Substantial hydrogen bonding leads to supramolecular layers in the  conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxylate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intramolecular amino-N—H⋯O(carboxylate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supramolecular chain by charge-assisted amine-N—H⋯O(carboxylate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N—H⋯O(carboxylate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N—O⋯π(arene) and methyl-C—H⋯O(nitro) interactions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N—H⋯O(carboxylate) hydrogen bonding. The formation of ammonium-N—H⋯O(carboxylate) hydrogen bonds, involving all ammonium-N—H and carboxylate O atoms leads to a three-dimensional architecture; additional C—H⋯O(nitro) interactions contribute to the packing. The Hirshfeld surface analysis confirms the importance of the hydrogen bonding in both crystal structures. Indeed, O⋯H/H⋯O interactions contribute nearly 50% to the entire Hirshfeld surface in (I).The crystal structures of two ammonium salts of 2-amino-4-nitrobenzoic acid are described, namely dimethylazanium 2-amino-4-nitrobenzoate, C The anion features an intramolecular amino-N—H⋯O(carboxylate) hydrogen bond (Table 1The molecular structures of the constituents of (I)d Table 1. Despitei.e. similar to the comparable angle in (I)i.e. with torsion angles of 173.0 (2)° (C23-chain) and 176.0 (2)° (C27-chain). The anions present similar conformations as in (I)The asymmetric unit of (II)c axis, Fig. 3a. Translationally-related chains stack along the a axis to define cavities in which reside the [Me2NH2]+ cations. These serve to link the anionic chains into layers via charge-assisted ammonium-N—H⋯O(carboxylate) hydrogen bonds, involving both carboxylate-O atoms. This association leads to the formation of centrosymmetric, 12-membered {⋯HNH⋯OCO}2 synthons, Fig. 3b. Layers stack along the a axis with the most notable interactions between the layers being nitro-N—O⋯π(arene) and methyl-C—H⋯O(nitro) contacts. The nitro-O4 atom is crucial in the formation of these contacts, being the donor and acceptor, respectively, Table 1c.As mentioned above, one H atom of the amino group forms an intramolecular hydrogen bond with the carboxylate-O1 atom. The second amino-H atom in (I)a. The result of this self-assembly is a centrosymmetric, 20-membered {⋯HNH⋯OCO⋯HNH⋯O}2 ring which encompasses two {⋯HNC3O} loops formed by the intramolecular amino-N—H⋯O(carboxylate) hydrogen bonds. Each of the cations associates with two anions in a very similar fashion to that in (I)2 synthon, Fig. 4b. The N6-ammonium H atoms form similar bridges but with the O5-anion. The result is the formation of a three-dimensional architecture, Fig. 4c.The crystal of (II)et al., 2016dnorm in the range −0.3 to + 1.8 au shown in Fig. 5a and b, the bright-red spots appearing near the amino-H2N, ammonium-H3N and H4N, and carboxylate-O1 and O2 atoms represent donors and acceptors of the dominating hydrogen bonds; they are viewed as blue and red regions on Hirshfeld surfaces mapped over electrostatic potential in the range −0.24 to + 0.31 au in Fig. 5c and correspond to positive and negative potentials, respectively. The faint-red spots at the methyl-H8C and nitro-O4 atoms in Fig. 5b are due to the presence of comparatively weak C—H⋯O interactions. Also from Fig. 5c, it is evident that the electrostatic coulombic interaction between the dimethylammonium and 2-amino-4-nitrobenzoate species results in a cation–anion pair through a C—H⋯π contact between methyl-H9C and the benzene (C1–C6) ring, as highlighted by the dotted bond. The immediate environment about the ion-pair within the Hirshfeld surface mapped over dnorm mediated by the above interactions is illustrated in Fig. 6Hirshfeld surface analysis for (I)In the crystal of the dibutylammonium salt, (II)dnorm, in the ranges −0.2 to +1.8 au for ion-pair 1, Fig. 8a, −0.1 to +1.6 au for ion-pair 2, Fig. 8b, and in order to reveal more detail (red-spots) on the surface, −0.1 to +1.6, for ion-pair 2, Fig. 8c. The bright-red spots appearing near amino-H2N and H4N, ammonium-H6N and H8N, and carboxylate-O1, O2, O5 and O6 atoms indicate donors and acceptors of charge-assisted N—H⋯O hydrogen bonds between the respective ion-pairs. The short interatomic O⋯H contact between the amino-H2N and nitro-O8 atoms, Table 3a, and nitro-O8 atoms, Fig. 8c. The faint-red spots present in Fig. 8b near atoms N4, C11, C13 and O6 of ion-pair 2 indicate their participation in short interatomic contacts in the crystal, Table 3c; the C27—H27A⋯O4 interaction is even weaker than these, showing no spots even at the lower dnorm range. The immediate environments about the ion-pairs within dnorm mapped Hirshfeld surface mediated by N—H⋯O hydrogen-bonding interactions are illustrated in Fig. 9Views of Hirshfeld surfaces mapped over et al., 2007a–g, respectively. The relative contributions from different contacts to the Hirshfeld surfaces of (I)The overall two-dimensional fingerprint plots for (I)c, shows that these contacts make the most significant contribution, i.e. almost half (49.4%), to the Hirshfeld surface. This may be due to salt formation through electrostatic interactions resulting in only a few hydrogen atoms being available on the surface to form interatomic H⋯H and other contacts. This is also reflected in a comparatively low contribution from H⋯H contacts to the Hirshfeld surface, Fig. 10b and Table 4de + di ∼1.8 Å in Fig. 10c is the result of charge-assisted N—H⋯O hydrogen bonds, Table 1d, having a fin-like distribution of points with tips at de + di ∼3.5 Å and a 4.8% contribution to the surface, indicate the presence of influential N—O⋯π and C—H⋯O interactions in the crystal of (I)e, is the result of a short interatomic contact, Table 3The fingerprint plot delineated into O⋯H/H⋯O contacts for (I)n-butyl side chains in the cations, cf. (I)b, and in the nearly same percentage contribution from these contacts in the plots for each ion-pair and overall Hirshfeld surface, Table 4de + di ∼2.2 Å in Fig. 10b is the result of short interatomic H⋯H contacts in the crystal, Table 3In the structure of (II)de + di ∼1.8 Å in the fingerprint delineated into O⋯H/H⋯O contacts, Fig. 10c, are a result of the N—H⋯O hydrogen bonds. A pair of regions comprising aligned green points in the plot beginning at de + di ∼2.7 Å are due to short interatomic O⋯H/H⋯O contacts present in the structure, Table 3e, and their different percentage contributions to the respective Hirshfeld surfaces, Table 4de + di ∼2.9 Å in the overall plot indicate short interatomic C⋯H/H⋯C contacts, Table 3A pair of long spikes with the tips at B is evident as a thin edge at de + di ∼2.7 Å in the overall fingerprint plot which results from the superposition of the individual plots for ion-pairs 1 and 2, Fig. 10f. The overall 1.4% contribution from C⋯O/O⋯C contacts results from short interatomic C⋯O contacts, Table 3de + di ∼3.2 Å in the overall fingerprint plot delineated into these contacts, Fig.10d.Though the interatomic N⋯H/H⋯N, C⋯O/O⋯C and C⋯C contacts each makes a small percentage contribution to the Hirshfeld surface of (II)g, is the result of π–π stacking between inversion-related benzene (C1–C6) rings  of ion-pair 1 and a 1.2% contribution from short C⋯C contacts in ion-pair 2, Table 3de + di ∼3.4 Å, Fig. 10g.The overall 1.4% contribution from C⋯C contacts to the Hirshfeld surfaces, Fig. 10Chemical context, a good number of ammonium salts of anions derived from 2-amino-4-nitrobenzoic acid have been described in the crystallographic literature. Salient geometric data for these are collated in Table 54]+ 6 ring. The greatest twist between the carboxylate and nitro substituents in any of the anions included in Table 3bAs indicated in the R2NH amine (0.1 mmol) in EtOH (5 ml) and 4-nitroanthranilic acid (0.1 mmol) in EtOH (10 ml) were mixed and left at room temperature. The yellow blocks of (I)R = Me salt: M.p. 428–431 (dec.) K. IR  3400–2500 (br), 1630, 1553, 1424, 1347, 1267, 1078, 822, 724, 692, 573 cm−1. R = n-Bu salt: M.p. 415–417 (dec.) K. IR: 3400–2500 (br) 1626, 1535, 1535, 1348, 1323, 1261, 825, 735 cm−1.The salts were isolated from the very similar reaction conditions. A solution of the respective Uiso(H) set to 1.2–1.5Ueq(C). The N-bound H atoms were located from difference maps but, refined with N—H = 0.88±0.01 Å, and with Uiso(H) = 1.2Ueq(N). In (II)i.e.  I, II, global. DOI: 10.1107/S2056989016017266/hb7627Isup2.hklStructure factors: contains datablock(s) I. DOI: 10.1107/S2056989016017266/hb7627IIsup3.hklStructure factors: contains datablock(s) II. DOI: Click here for additional data file.10.1107/S2056989016017266/hb7627Isup4.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989016017266/hb7627IIsup5.cmlSupporting information file. DOI: 1511822, 1511821CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The amino groups and the pyridine N atom engage in intermolecular hydrogen bonding. The molecules pack into spiral hydrogen-bonded columns with offset face-to-face π-stacking.The  ortho-amino groups of the title compound, C5H6ClN3, twist out of the plane of the molecule to minimize intramolecular interaction between the amino hydrogen atoms. In the crystal, the amino groups and the pyridine N atom engage in intermolecular hydrogen bonding. The molecules pack into spiral hydrogen-bonded columns with offset face-to-face π-stacking.The two  While all of the sixteen isomers of 5-chloropyridine-2,3-diamine are commercially available, none of their crystal structures have been reported in the literature. 5-Chloropyridine-2,3-diamine may be produced by nitrating 2-amino-5-chloropyridine with nitric acid to give 2-amino-3-nitro-5-chloropyridine, which is then reduced with sodium dithionite  and 34 (3)° for N2 and N3, respectively. It is notable that the achiral title compound crystallizes in a non-enantiogenic (Söhncke) space group, although not a polar space group.The molecular structure of the title compound 5-chloropyridine-2,3-diamine Fig. 1 shows thamine—H⋯Npyr and Namine—H⋯Namine hydrogen bonding interactions and offset face-to-face π-stacking. The molecules connect into a one-dimensional strip running parallel to the crystallographic b axis  −x + 2, y − z + amine—H22⋯N1iiipyr  and 2-amino-3-chloropyridine (URAXER) [1.351 (4) Å]. 2-amino-5-chloropyridine (AMCLPY12), which does not have the meta-NH2 substitution of the title compound, packs in a herringbone formation featuring centrosymmetric head-to-tail Namine—H⋯Npyr hydrogen bonding dimers with donor–acceptor distance 3.031 (2) Å. 2-Amino-3-chloropyridine (URAXER), has a meta-Cl substitution in place of the meta-NH2 in the title compound. Like 2-amino-5-chloropyridine (AMCLPY12), 2-amino-3-chloropyridine (URAXER) features a herringbone packing with centrosymmetric head-to-tail Namine—H⋯Npyr hydrogen-bonded dimer with a similar donor–acceptor distance of 3.051 (5) Å. The similar hydrogen-bonding motif in these two related compounds differs from the title compound, which does not exhibit centrosymmetric hydrogen-bonding dimerization. 2-Amino-3-chloropyridine (URAXER) also has short intermolecular Cl⋯Cl interactions of 3.278 (3) Å, where no such short halogen–halogen contact was observed in 2-amino-5-chloropyridine (AMCLPY12) or the title compound.The Cambridge Structural Database  was purchased from Aldrich Chemical Company, USA. A single crystal suitable for analysis was selected from the purchased sample and used as received.1H NMR : δ 4.99 , 5.55 , 6.69 , 7.21 . 13C NMR : δ 116.58 (CarylH), 118.38 (Caryl), 131.32 (Caryl), 131.66 (CarylH), 147.10 (Caryl). IR : 3392 , 3309 , 3172 , 1637 , 1572 (m), 1472 (s), 1421 (m), 1347 (w), 1307 (w), 1280 (w), 1240 (m), 1068 (m), 939 (w), 887 (w), 861 (m), 792 (m), 770 (m), 680 (s), 630 (s), 568 (s), 490 (s), 449 (s). GC/MS (Hewlett-Packard MS 5975/GC 7890): M+ = 143 .Uiso(H) = 1.2Ueq(C) of the aryl C-atoms. The positions of the four amino hydrogen atoms were found in the difference map and they were refined semi-freely using a distance restraint d(N—H) = 0.91 Å, and Uiso(H) = 1.2Ueq(N).Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989017010489/fy2122sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989017010489/fy2122Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989017010489/fy2122Isup3.cmlSupporting information file. DOI: 1562267CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Curved π-conjugated diradicaloids based on bridged corannulene dimers were synthesized, showing 3D spin delocalization and global aromaticity for their dianions. Cor-D1 and Cor-D2, both showing a three-dimensional curved π-conjugated structure. Cor-D1 has a small diradical character (y0 = 5.4%) and behaves more like a closed-shell quinoidal compound at room temperature, while Cor-D2 is a typical open-shell diradicaloid with a larger diradical character (y0 = 16.9%). Both compounds exhibited paramagnetic activity at elevated temperatures, with a singlet–triplet energy gap (ΔES–T) of –8.4 and –3.0 kcal mol–1, respectively. X-ray crystallographic analysis revealed that both molecules have a dumbbell-shaped geometry, with the two terminal corannulene bowls bent to opposite directions. The spin is largely delocalized onto the two bowls in Cor-D2 and there are multiple [CH···π] interactions between the neighboring bowls. Chemical oxidation/reduction to their respective dications/dianions results in global aromaticity with [4n + 2] π-electrons delocalized through the periphery of the whole framework.So far, most reported open-shell singlet diradicaloids are based on planar π-conjugated molecules. Herein, we report the bridged corannulene dimer diradicaloids,  Cor-Ver (verzazyl), Cor-IN (iminonitroxide), Cor-PhO (phenoxyl) and tBuNOCor- (tert-butylnitroxide) (Cor-PLY (Cor-2PhO showed significant intramolecular magnetic interaction with a singlet–triplet energy gap (ΔES–T = 2JkB–1) of –810 K .Cor-D1 and Cor-D2, in which the two corannulene units are annulated with a para-quinodimethane (p-QDM) and 2,6-naphthoquinodimethane  moiety, respectively   were pre(Cor-PLY  was not ectively . The cenectively .1 (1 at the ortho-position by N-bromosuccinimide (NBS) in the presence of diisopropylamine gave the 1-bromo-2-methoxy-corannulene 2 in 85% yield. The bromo-group was then converted into pinacol boronate in 3 by lithiation followed by quenching with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane. Suzuki coupling reaction between 3 and the 2,5-dibromoterephthalaldehyde (4) or 3,7-diformylnaphthalene-2,6-diyl bis(trifluoromethanesulfonate) (5)6a or 6b. Nucleophilic addition of the aldehyde groups in 6a/6b with excessive mesitylmagnesium bromide generated the diol intermediates and subsequent BF3·Et2O mediated intramolecular Friedel–Crafts alkylation afforded the dihydro-precursors 7a/7b. At this step, the existence of a methoxy group on each corannulene unit ensured a six-membered ring cyclized product only and avoided possible formation of five-membered rings.7a/7b with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in toluene at 80 °C gave the final desired products Cor-D1 and Cor-D2, respectively. The bulky mesityl groups are essential to kinetically block the reaction sites and also make the final products reasonably soluble. Both Cor-D1 and Cor-D2 are stable and can be purified by normal silica gel column chromatography.The synthesis of π-extended corannulenes is challenging1   of Cor-D1 is measured to be 0.89 Å, which is slightly larger than that of parent corannulene (d = 0.87 Å),Cor-D2 shows even larger bowl depth of 0.94 Å. No intermolecular close contact is found between Cor-D1 molecules, and chlorobenzene molecules fill the void with [CH···π] interactions with backbone of Cor-D1. On the other hand, multiple [CH···π] interactions (distance: 2.711 Å) between neighboring corannulene bowls are found in the crystallographic structure of Cor-D2, and there are additional [CH···π] interactions between the methyl groups and the corannulene bowls (distance: 2.736 Å), both drive the molecules into a densely packed structure   Å), is significantly longer than that of typical olefins (1.33–1.34 Å), implying certain contribution of diradical form. The central 2,6-NQDM unit in Cor-D2 also has significant BLA, with the exo-methylene C1–C2 bond being elongated (1.389(8) Å)  of 5.4% and 16.9%, respectively. Interestingly, a dihydro-product (Cor-D2-2H), the anti-isomer of 7b, was found during the crystal growth of Cor-D2 by slow evaporation of chlorobenzene at 60 °C. The structure was confirmed by X-ray crystallographic analysis  revealed splitting of the protons for both the central benzenoid ring, the OMe group, and the ortho-methyl groups in the mesityl substituents below the coalescent temperature Tc   and the other with two terminal bowls bent to the same directions (syn-form). Our calculations ) predict that the syn-form is 0.538 kcal mol–1 higher in energy than the anti-isomer  = –ΔH‡/R × 1/T + ln(kB/h) + ΔS‡/R) gave thermodynamic parameters ΔH‡ = 19.8 ± 0.6 kcal mol–1 and ΔS‡ = 21.9 ± 2.3 cal (mol–1 K). Accordingly, ΔG‡ was estimated to be 13.3 ± 1.3 kcal mol–1 at 298 K  but slightly smaller than that of the corannulene annulated with a –CH2–CE2–CH2– (E = COOCH3) ring .12Cor-D2 showed similar behavior with slightly lower Tc   and ΔG‡ (298 K) = 13.0 ± 3.0 kcal mol–1  , indicat89(8) Å) . NaturalC2 (1.388 Å), is sCor-D1 is blue while Cor-D2 is green in dichloromethane (DCM). Cor-D1 shows an intense absorption band with maximum (λmax) at 612 nm  signal  of –8.4 kcal mol–1 . However, NMR spectral broadening in toluene-d8 was observed along with the elevated temperatures from 333 K to 373 K  increased after 150 K and fitting of the data using Bleaney–Bowers equation gave a moderate ΔES–T = –3.0 kcal mol–1  under heating (50 °C) which can suppress molecular aggregation and give better resolved redox waves . The HOMO and LUMO energy levels were calculated to be –5.03 and –3.38 eV from the onset of the first oxidation/reduction wave, respectively, and an electrochemical energy gap (EECg) of 1.65 eV was estimated. Cor-D2 showed two reduction waves at Ered1/2 = –1.28 and –1.56 V, with a LUMO energy level of –3.52 eV. Due to strong aggregation, clear oxidation wave could not be observed. Both compounds can be chemically oxidized into radical cation and dication by NO·SbF6 in dry DCM, and reduced into radical anion and dianion by sodium anthracenide (NaAn) in anhydrous THF . The dianion and dication exhibit similar band structure and trend . Clear 1H NMR spectra of the dianions of Cor-D1 and Cor-D2 can be recorded by in situ reduction with NaAn in anhydrous THF-d8 and most of the aromatic protons appear above 7 ppm despite their electron-rich character zz valuezz value of the central benzene ring becomes largely negative (–30.66 ppm), and even the inner cyclopenta-ring in the each corannulene unit shows significantly negative NICS(1)zz value (–14.75 ppm), indicating a strong global aromatic system. Apparently, 38 π electrons can be counted along the periphery, which satisfies Hückel's [4n + 2] aromaticity rule. Its dication exhibits similar global aromaticity with 34 π electrons delocalized along the periphery. The NICS(1)zz value of the central benzene ring (–12.45 ppm) is less negative than that in dianion, and that of the cyclopenta-ring becomes quite positive (+34.13 ppm), indicating relatively weak global aromaticity. In the anti-Cor-D2, the two corannulene bowls remain their individual aromatic character similar to that in Cor-D1, but diamagnetic ring current was found in the central naphthalene unit (NICS(1)zz: –10.18 ppm), indicating significant contribution of the open-shell diradical form. Its dianion also show global aromaticity with 42 π-electrons delocalized along the periphery and the NICS(1)zz value in the central naphthalene ring is shifted to –26.98 ppm. Its dication does not display global aromaticity as 2+Cor-D1, and the localized aromaticity at the central naphthalene unit dominates (NICS(1)zz: –12.74 ppm), making the two corannulene units somehow segregated. The radical anions and radical cations of both compounds with unpaired electron show partial global aromatic character  plotp-QDM and 2,6-NQDM bridged corannulene dimers Cor-D1 and Cor-D2 were synthesized in stable form, which represent a new type of curved π-conjugated open-shell singlet diradicaloids. Cor-D1 has a small diradical character and behaves more like a closed-shell hydrocarbon at room temperature, while Cor-D2 possesses a moderate diradical character. Both compounds display magnetic activity at elevated temperatures. Electronic spins are distributed onto both corannulene bowls in Cor-D2, and stronger intermolecular interactions and more ordered packing are observed in its single crystals. Notably, their dianions show prominent global aromaticity with [4n + 2] π electrons delocalized along the periphery. Our studies reveal the unique electronic structure of such kind of bowl-shaped π-conjugated polycyclic hydrocarbons, which implies their potential applications for organic electronic and spintronic devices in the future.In summary, rigid, There are no conflicts to declare.Supplementary informationClick here for additional data file.Crystal structure dataClick here for additional data file.


The same type of N—H⋯O=C hydrogen-bonded chain has previously been found in several 5,5-disubstituted derivatives of barbituric acid which are chemically closely related to (I) and (II).The molecule of buthalital, (I) , C Buthalital (I)The molecular structure of (I)sec-butyl group (r.m.s. deviation = 0.091 Å) forms an angle of 88.64 (5)° with the mean plane of the pyrimidine ring and an angle of 39.0 (1)° with the mean plane of the  fragment of the nearly planar (r.m.s. deviation = 0.070) sec-butyl group. In the 2-(methylthio)ethyl substituent, the C10—S9 and C8—S9 bond lengths are 1.794 (2) and 1.803 (2) Å, respectively, and the C7—C8—S9—C10 torsion angle is 82.5 (2)°. The bond between ring atom C5 and atom C12 of the sec-butyl group [1.582 (2) Å] is somewhat longer than the analogous distance between C5 and atom C7 of the 2-(methylthio)ethyl group [1.547 (2) Å]. This difference is reminiscent of the difference between equatorial and axial bonds at ring atom C5 found in several 5,5-disubstituted barbituric acid derivatives that exhibit a puckered pyrimidine ring  in the molecule of (II)i and N3—H3⋯O6ii bonds C-2 type, which also occurs in a number of 5,5-disubstituted barbituric acid derivatives ds Fig. 3. Each moi and N3—H3⋯O4ii, are present in the crystal structure of (II)C-2 chain structure is formed that propagates parallel to the c axis. In this case, the C-2 chain contains two crystallographically distinct sec-butyl group of a molecule belonging to a neighbouring chain and S2 lies in close proximity to the methyl group of a 2-(methylthio)ethyl substituent (S⋯H = 2.96 Å).Two independent hydrogen bonds, N1—H1⋯O6re Fig. 4. The meaet al., 2010hcb topology and polymorph IV (THBARB02) an N—H⋯O-bonded framework. Both these structures contain N—H⋯O-bonded sql topology whose molecules are linked exclusively by one-point connections and an hcb-type layer based on N—H⋯O as well as N—H⋯S bonds, with the latter interaction resulting in The crystal structures of three polymorphs of the keto form of 2-thiobarbituric acid, which is a close structural analogue of (I)C-1 and C-2 Numerous 5,5-substituted derivatives of barbituric acid are known to form N—H⋯O=C-bonded chains exhibiting the 2C1 topology, with their molecules being linked by two-point connections resulting in the formation of characteristic C-2 chains containing a 21 screw axis occur in polymorph III of phenobarbital (PHBARB09), the CH2Cl2 solvate of the same compound (EPUDEA)  The crystals of (II)Uiso parameters of all H atoms were refined freely.Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S205698901701653X/dx2002sup1.cifCrystal structure: contains datablock(s) I, II, global. DOI: 10.1107/S205698901701653X/dx2002Isup2.hklStructure factors: contains datablock(s) I. DOI: 10.1107/S205698901701653X/dx2002IIsup3.hklStructure factors: contains datablock(s) II. DOI: Click here for additional data file.10.1107/S205698901701653X/dx2002Isup4.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S205698901701653X/dx2002IIsup5.cmlSupporting information file. DOI: 10.1107/S205698901701653X/dx2002sup6.pdfHot-stage microscopy. DOI: 1586016, 1586015CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Nardostachys chinensis Batal. led to the isolation of forty sesquiterpenoids including six new aristolane-type sesquiterpenoids and six new nardosinane-type sesquiterprenoids. Their structures were elucidated by extensive spectroscopic methods, combined with analyses of circular dichroism and single-crystal X-ray diffraction data. To explore natural product scaffolds with SERT regulating activity, a high-content assay for measurement of SERT function in vitro was conducted to evaluate the SERT regulating properties of these isolates. In conclusion, eleven compounds could be potential natural product scaffolds for developing drug candidates targeting SERT. Among which, kanshone C of aristolane-type sesquiterpenoid inhibited SERT most strongly, while desoxo-nachinol A of nardosinane-type sesquiterpenoid instead enhanced SERT potently.Serotonin transporter (SERT) is a classic target of drug discovery for neuropsychiatric and digestive disorders, and against those disorders, plants of Nardostachys genus have been valued for centuries in the systems of Traditional Chinese Medicine, Ayurvedic and Unani. Herein, chemical investigation on the roots and rhizomes of  At enterochromaffin cells in the digestive system, SERT inactivates the stimulant effects of 5-hydroxytryptamine on gastrointestinal tract mucosa, and it plays important roles in the pathophysiology of digestive disorders such as irritable bowel syndrome, slow transit constipation and functional abdominal bloating3. To screen SERT activity of the candidate compounds, the high-content assay for measurement of SERT function based on human embryonic kidney 293 cell line stably expressing human SERT (hSERT-HEK) and the fluorescent substrate 4-[4-(dimethylamino)phenyl]-1-methylpyridinium (APP+) has been established5, and this novel method is more feasible in practice than the traditional isotope labeling uptake assay.Serotonin transporter (SERT) is a classic target of drug discovery for neuropsychiatric and digestive disorders. At serotonin synapses in the central nervous system, SERT is responsible for the reuptake of 5-hydroxytryptamine into presynaptic neurons, and it is implicated in the occurrence of mood disorders, for instance, depression, anxiety or obsessive-compulsive disorderNardostachys chinensis Batal. (NCB) has been studied. NCB is mainly distributed in Sichuan, Gansu, Qinghai and Xizang areas in China. The root and rhizome of NCB have been used as both herbal drugs and functional foods for centuries to treat digestive disorders in traditional Chinese medicine6. Modern pharmacological studies demonstrated that NCB show bioactivities in against depression, arrhythmia, convulsion, myocardial ischemia and hypertension7. This plant was enriched with bioactive sesquiterpenoids, among which aristolane-, nardosinane-, and guaiane- types of sesquiterpenoids were the representative constituents9. Herein, we report the isolation, structure elucidation and effects on SERT function of six new and twelve known aristolane-type sesquiterpenoids  to give six new  and twelve known aristolane-type sesquiterpenoids  and sixteen known nardosinane-type sesquiterpenoids 10, nardoaristolone B (2)11, 1(10)-aristolen-9β-ol (4)12, kanshone C (5)13, kanshone H (8)14, (−)-aristolone (9)15, (−)--aristolone (10)16, kanshone F (12)8, kanshone G (13)8, debilon (15)17, nardostachone (16)18, 1(10)-aristolen-2-one (17)19, nardosinone (20)17, nardosinonediol (21)17, kanshone A (25)17, kanshone E (27)20, isonardosinone (28)20, nardosinanone H (29)9, -4a,5-dimethyl-4-(1-methylethenyl)-4a,5,6,7-tetrahydronaphthalen-1(4 H)-one (31)21, nardosinanone I (32)9, nardosinanone B (33)22, nardosinanone G (34)9, nardosinanone M (35)10, nardonoxide (36)12, nardosinanone F (37)9, desoxo-nachinol A (38)17, narchinol B (39)23 and narchinol A (40)24, respectively. The structures of the new compounds were deduced by analysis of extensive spectroscopic data .The 70% aqueous ethanol extract of the air-dried roots and rhizomes of 1) was isolated as colorless needles. The 1H and 13C NMR data (Supplementary Table 1 was similar to that of nardoaristolone B (2), except that the two olefinic carbons (C-1 and C-9) in 2 were replaced by the two oxygenated carbons in 1 , indicating the existence of an oxiran ring adjacent to carbonyl in 1. Analysis of the HSQC and HMBC spectroscopic data supported the assignments of its 1D NMR data, which were identical with those data recently reported by other groups in this April.Nardoaristolone C  data, together with the NOESY correlations between δH 1.97 (H-6) and δH 1.04 (H3-13), and between δH 1.56 (H3-12) and δH 2.57 (H-4)/1.20 (H3-11). For X-ray crystallographic analysis of light atom structures , if a heavier element  is not contained in the crystals, the anomalous scattering with molybdenum (Mo) radiation is always too small to assign the absolute configuration25. Herein, the absolute configuration of 1 was then assigned by comparing its CD data with those of 2  was isolated as a colorless oil, and epoxynardosinone (19) was isolated as colorless crystals. Their molecular formulas were confirmed respectively to be C15H24O2 and C15H22O4 by analysis of their NMR and ESIMS data. The 1H and 13C NMR data (Supplementary Table 3 and 19 were similar to those of 1(10)-aristolen-9β-ol (4) and nardosinone (20), except that the olefinic carbons (C-1 and C-10) in 4 and 20 were replaced by the oxygenated carbons of two oxiran rings in 3  and 19 , respectively. The deduction was further confirmed by analysis of the HSQC and HMBC spectroscopic data and the relative configurations of 3 and 19 were assigned by the 2D NOESY experiments  was established by comparison of its 1D/2D NMR spectroscopic data with those of nardosinanone H (29).Nardoaristol (dosinone 9 was iso6) was isolated as a colorless oil, and 3-oxokanshone H (7) was isolated as a white amorphous powder. Analysis of their ESIMS and NMR data established the molecular formulas to be C15H20O2 and C15H18O2. On the basis of the HSQC and HMBC spectra, the structures of 6 and 7 were elucidated as 3-hydroxylaristol-1,9-dien-8-one  and aristol-1,9-dien-3,8-dione , indicating that they were 3-hydroxyl and 3-oxo derivatives of kanshone H (8), respectively. The β configuration of the 3-hydroxyl group in 6 was deduced from the key NOESY correlations /H3-15 (δH 1.27).3-Hydroxylkanshone H -epoxidation derivative of the known aristolane-type sesquiterpenoid (4) and its CD spectrum also showed negative Cotton effects (<215 nm), the absolute configuration of 3 was proposed as shown in Fig. Based on the above deduced relative configurations, the absolute configurations of the new compounds 11) and 9β-debilon (14) were found out to be two new stereoisomers of the reported structures axinysone B27 and debilon (15), respectively. 1D NMR data of 11 was exactly the same as those reported for axinysone B, but the optical rotation and CD data of 11 was opposite to those of axinysone B, indicating that the two compounds are a pair of enantiomers. The experimental CD spectrum of 11 was further compared with the computational ECD spectra of the -11a and -11b obtained by time-dependent density functional theory (TDDFT) quantum mechanics [B3LYP/6–31 G(d)]28. The excellent agreement of the experimental and computational ECD spectra . 14 was elucidated as a 9β-hydroxyl epimer of 15 (debilon) by analysis and comparison of the spectroscopic data  for compounds 14 and 15.Based on the comparisons of 1D/2D NMR data, 1-hydroxylaristolone (18) was isolated as a white amorphous powder with a molecular formula of C15H20O3, deduced by analysis of the HRESIMS  and NMR data. The 1H NMR spectrum of 18 revealed the existences of four methines , two methylenes  and four methyls  in 18. Furthermore, the 13C NMR spectrum of 18 suggested a double bond (δC 141.2 and 137.4) and two ester carbonyls (δC 176.1 and 171.8) were included in the structure of 18. HMBC correlations from δH 6.65 (H-1) to δC 171.8 (C-10), 141.2 (C-11), 41.4 (C-5) and 24.1 (C-2), from δH 0.89 (H3-16) to δC 41.4, 37.4 (C-4) and 26.5 (C-3), from δH 1.44/1.18 (H3-13/14) to δC 46.4 (C-6) and 30.3 (C-12), from δH 1.37 (H-6) to δC 176.1 (C-8) and from δH 1.33 (H3-15) to δC 46.4 then established the planar structure of 18, a rare 8,9-cleavage anhydride derivative of aristolane-type sesquiterpenoid. The stereochemistry problem of 18 was solved by NOESY experiment and comparison of its experimental ECD spectrum with the computational ones , 7-oxonardosinone (23), 7-oxonardosinoperoxide (24) and 2-oxokanshone A (26), were established by comparing their NMR data (Supplementary Tables 21 (nardosinonediol) and 25 (kanshone A). Compound 24 was deduced as a peroxide compound on the basis of its positive HRESIMS  and NMR data. Furthermore, the absolute configurations of these compounds were all proposed as shown in Fig. The structures of other four new nardosinane-type sesquiterpenoids, nardosinonetriol 2, 7-oxonosinone 2, 7-oxona2, 4, 6–8, 11, 16, 19, 23–24, 27–29, 32–33, 36, 38 and 40 enhanced SERT activity while compounds 5, 12–13, 17, 20–21, 30, 35 and 37 inhibited SERT activity. Compounds 1, 9, 15, 18, 22, 25, 26, 31 and 34 did not show any SERT activity meanwhile compounds 3, 10, 14 and 39 were not tested due to insufficient amount. For the SERT enhancers, nardoaristolone B (2), nardonoxide (36) and desoxo-nachinol A (38) showed potent effects, among which a 4,11-O-briged nardosinane-type sesquiterpenoid  with a 5/6/6 tricyclic ring system showed the strongest effect; 1(10)-aristolen-9β-ol (4), kanshone H (8), nardostachone (16), 7-oxonardosinoperoxide (24), kanshone E (27) and nardosinanone H (29) were in the middle; and 3-hydroxylkanshone H (6), 3-oxokanshone H (7), 1-hydroxylaristolone (11), epoxynardosinone (19), 7-oxonardosinone (23), isonardosinone (28), nardosinanone I (32) and nardosinanone B (33) showed weak effects, however, 8 exhibited stronger effect than its 3-hydroxyl derivative (6) and 3-oxo derivative (7), 23 exhibited weaker effect than its 9-peroxide derivative (24), and 28 showed weaker effect than its 2-oxo derivative (27). For the SERT inhibitors, kanshone C (5), nardosinone (20) and nardosinonediol (21) significantly inhibited SERT activity. Further analysis suggested that 1(10) or 1(9)-epoxidation of the double bond  seems to inactivate or reverse the aristolane-type and nardosinane-type sesquiterpenoids’ regulation effects on SERT activity.As shown in Table 5), and the SERT enhancers 1(10)-aristolen-9β-ol (4) and nardostachone (16), are derived from compound 4.Both enhancer and inhibitor of SERT, interestingly, were identified in the two main types of sesquiterpenoids  from NCB, and the SERT enhancers are richer in quantity than the SERT inhibitors. According to the proposed biosynthetic pathways -5-fluoroindole53, have been developed by chemical modification or hybridization of the known clinical antidepressants, based on the molecular templates shown in Fig. 54. As far as we know, this is the first report on SERT activities of the natural aristolane-type and nardosinane-type sesquiterpenoids. Further, according to the above structure-activity discussion of known SIs, it suggests that eleven compounds  and three SERT inhibitors  may provide novel potential scaffolds for synthesis of SERT regulators.Reported or marketed clinical antidepressants of the SERT mechanism, as known, include SERT inhibitors as well as SERT enhancers. SERT inhibitors (SIs) are dominant containing tricyclic antidepressants, selective serotonin reuptake inhibitors and selective noradrenaline reuptake inhibitorsNardostachys chinensis Batal., and their structures were identified by combined modern spectroscopic methods. Among these compounds, eleven natural scaffolds bidirectionally regulate SERT activity. They are potential lead compounds for regulation of SERT activity in drug discovery and provide novel molecular templates for synthesis of SERT enhancers and inhibitors, especially enhancer of SERT, which is rare so far in drug discovery. Presently, we are exploiting more SERT regulation lead structures from NCB and investigating antidepressant effect of SERT regulators in vivo assays to be reported in due time.In conclusion, forty sesquiterpenoids were isolated from roots and rhizomes of TM Elite system . 1D and 2D NMR spectra were recorded on a Bruker AV-III spectrometer  using TMS as an internal standard. Chemical shifts (δ) were expressed in ppm. X-ray crystal data were analyzed on Rigaku MicroMax-007HF , preformed with Mo Kα. Preparative HPLC was performed on Waters 2489 HPLC system  using an Agilent Zorbax SB-C18 ODS column . Column chromatography (CC) was carried out with silica gel , sephadex LH-20  and D101 macroporous resin . Column fractions were monitored by TLC , and the spots were visualized by heating the plates after spraying with 10% H2SO4 in ethanol. All reagents of HPLC or analytical grade were purchased from Tianjin Damao Reagent Co., Ltd., Tianjin, China.Optical rotations were measured using a Rudolph AUTOPOL V polarimeter . UV and electronic circular dichroism spectra were obtained on a Jasco J-815 circular dichroism spectropolarimeter . ESIMS was performed on a Waters Synapt G2 mass spectrometer , and HRESIMS spectra was obtained on a quadrupole time-of-flight mass spectrometer QSTARNardostachys Chinensis Batal. by Prof. Tian-xiang Li, Tianjin University of Traditional Chinese Medicine. A voucher specimen (No. B20604126) was deposited in the Tianjin Key Laboratory of Modern Chinese Medicine, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China.The air-dried plant materials were purchased from Anhui Jiren Pharmacy Co. Ltd.  in July, 2011, and were identified as roots and rhizomes of v/v) at a speed of 10 ml/min under room temperature, and the residues were then reflux extracted 3 times (2 hours each time) by 8 times amount of 70% ethanol at 80–90 °C. The combined 70% ethanol solution was concentrated to dryness in vacuo (3.4 kg) and resuspended in water before being partitioned successively with petroleum ether, ethyl acetate, and n-butanol to give petroleum ether (PE), ethyl acetate (EA), and n-butanol (BU) extracts. The BU extract, combined with the extract afforded by alcohol precipitation of the rest water solution, was chromatographed on D101 macroporous resin column, gradiently eluted with EtOH/H2O (0:100−95:5) to obtain 5 fractions . Among them, the 95% EtOH fraction was concentrated to dryness in vacuo before combined with the EA extract. The PE extract (320 g) was fractionated by silica gel CC, gradiently eluted with PE/EA (100:0–0:100) to obtain 22 primary fractions Fr.1–Fr.22. Fr.5 (120.0 g) was successively subjected to a sephadex LH-20 CC  and a silica gel CC  to afford 6 subfractions Fr.5–1–5–6, among which, Fr.5–1 gave compound 30  and Fr.5–5 gave compound 29  after purifications by preparative thin layer chromatography (pTLC) over silica gel. Fr. 6 (57.0 g) and Fr. 9 (40 g) were then subjected to repeated silica gel CC  to afford compounds 2 (13 mg), 4 (280 mg), 5 (10 mg), 16 (250 mg), 20 (240 mg), 26 (3 mg) and 36 (4 mg). One subfraction Fr.6–4–5 from Fr.6 was further subjected to semi-preparative HPLC (MeOH:H2O = 80:20) to give compound 13 . Fr.7 (70 g) was separated by reverse phase ODS CC  to give 6 subfractions Fr.7–1–7–6. Fr.7–1 was then subjected to repeated silica gel CC  to give compounds 1 (8 mg), 19 (6 mg) and 32 (8 mg). Similarly, Fr.7–2–7–4 were subjected to repeated silica gel CC  to give compounds 23 (5 mg), 24 (6 mg) and 27 (3 mg). The remain subfractions from Fr.7–2–7–4 were further purified by silica gel pTLC eluted with PE/EA/methanol  to afford compounds 3 , 6 , 7 , 15 , 17 , 38 , 35  and 40 . Compounds 8 (15 mg) and 9 (12 mg) were obtained by recrystallization of the subfraction Fr.7–2–2–1, and compound 10 (3 mg) was given by recrystallization of the subfraction Fr.7–2–2–9. Fr.10 (35 g) was successively subjected to a sephadex LH-20 CC  and a silica gel CC  to afford 28 (7 mg). Fr.13 (54 g) was fractionated by silica gel CC  to subfrations Fr.13–1–Fr.13–6. Fr.13–2 was then subjected to silica gel pTLC to give compound 25 . Fr. 15 (7.0 g) was subjected to silica gel CC  to obtain 18 primary fractions Fr.15–1–Fr.15–18. Subfraction Fr.15–1 was then subjected to semi-preparative HPLC (MeOH:H2O = 60:40) to afford compound 37 . Fr. 17 (3.0 g) was then subjected to silica gel CC  to obtain 16 sufractions Fr.17–1–Fr.17–16. Subfraction Fr.17–9 was further isolated by semi-preparative HPLC (MeOH:H2O = 65:35) to yield compound 34 .The air-dried roots and rhizomes (20.0 kg) of NCB were first percolated 3 times by 8 times amount of 70% ethanol (2Cl2/MeOH (100:0–0:100) to obtain 15 primary fractions Fr.1–Fr.15. Fr.10 (40 g) was subjected to silica gel CC eluted with 100% EA to get 8 subfratcions Fr.10–1–Fr.10–8. And then, subfraction Fr.10–3 was successively subjected to a sephadex LH-20 CC (100% MeOH) and a silica gel CC  to give compound 21 (17.5 mg). Fr.1 (782 g) was separated into 12 subfractions Fr.1–1–Fr.1–12 by normal-phase silica gel CC . Subfraction Fr.1–1 (25 g) was then subjected to repeated silica gel CC to give 15 fractions Fr.1–1–1–Fr.1–1–15. Fraction Fr.1–1–5 was fractionated to 6 subfractions Fr.1–1–5–1–Fr.1–1–5–5 by preparative HPLC , and then subfraction Fr.1–1–5–1 was further purified by preparative HPLC (MeCN:H2O = 35:65) to yield compound 31 . Similarly, subfraction Fr.4–2–3–2 afforded by repeated silica gel CC of Fr.4, was subjected to semi-preparative HPLC (MeOH:H2O = 65:35) to yield compound 12 . Fr.1–5 (16 g) was isolated by preparative HPLC  to afford 6 fractions Fr.1–5–1–Fr.1–5–6, among which fracion Fr.1–5–5 was purified to yield compound 18 . Fr.1–9 (18 g) was separated into 10 fractions Fr.1–9–1–Fr.1–9–10 by preparative HPLC , and fraction Fr.1–9–6 was further isolated by preparative HPLC (MeCN:H2O = 45:55) to yield compound 11 . Subfraction Fr.1–2 (80 g) was chromatographed on silica gel CC eluted with PE/EA (from 50:1 to 0:100) to obtain 11 fractions Fr.1–2–1–Fr.1–2–11. Fraction Fr.1–2–11 was then purified to yield compound 14  by preparative HPLC .The EA extract (1200 g) was fractionated by silica gel CC, gradiently eluted with CH2O (10:90–100:0) to obtain 5 subfractions . The 10% MeOH subfraction was subjected to repeated sephadex LH-20 CC (50% aqueous MeOH or 100% MeOH) to afford compounds 22 (11.8 mg) and 33 (11.0 mg), and the rest samples were further isolated by preparative HPLC (MeOH:H2O = 28:72) to afford compound 39 .The 30% aqueous ethanol fraction (190 g) from the BU extract (1800 g) was then subjected to D101 macroporous resin column, gradiently eluted with MeOH/HThe NMR spectra of the new compounds are provided in the Supplementary Information.α]20 D =  +18.00 ; UV (MeOH) λmax 197.5; CD  λ(Δε) 209.5 (−0.03), 215.5 (+0.012), 219 (−0.005), 221.5 (+0.02); 1H NMR  and 13C NMR data , see Supplementary Table m/z 235.19 [M−H]−, ( + )-ESIMS m/z 237.27 [M + H]+.Colorless oil (EtOAc); [α]20 D = −50.13 ; UV (MeOH) λmax 283.0; CD  λ(Δε) 213.5 (+1.32), 275.5 (+0.08), 296.0 (+0.66), 336.5 (−3.55); 1H NMR  and 13C NMR data , see Supplementary Table m/z 231.1385 [M−H]− ; (−)-ESIMS m/z 231.30 [M−H]−, (+)-ESIMS m/z 255.28 [M + Na]+.Colorless oil (EtOAc); 20 D = −391.88 ; UV (MeOH) λmax 198, 290; CD  λ(Δε) 197 (−1.11), 221 (9.40), 307 (−3.12), 348 (−2.24); 1H NMR  and 13C NMR data , see Supplementary Table m/z 231.1378 [M + H]+ ; (−)-ESIMS m/z 229.97 [M−H]−, (+)-ESIMS m/z 231.33 [M + H]+.White amorphous powder ; UV (MeOH) λmax 195, 230; CD  λ(Δε) 201 (+3.20), 257 (−4.74), 294 (−0.71), 328 (−2.23); (−)-HRESIMS m/z 233.1544 [M−H]− ., (+)-HRESIMS m/z 235.1670 [M + H]+ .Colorless needles (MeOH); 20 D = −33.31 ; UV (MeOH) λmax 198, 290; CD  λ(Δε) 200 (−1.85), 218.9 (−0.09), 243.2 (−0.83), 260.8 (−0.45), 318.5 (−0.51), 379.4 (+0.07); 1H NMR  and 13C NMR data , Supplementary Table m/z 251.1646 [M + OH]− . (+)-HRESIMS m/z 257.1498 [M + Na]+ .Colorless crystals (CH2Cl2); [α]20 D = −67.00 ; UV (MeOH) λmax 210, 285; CD  λ(Δε) 200 (−1.44), 209 (−0.62), 224 (−2.15); 1H NMR  and 13C NMR data , see Supplementary Table m/z 249.1469 [M + H]+ ; (−)-HRESIMS m/z 265.1441 [M + OH]− .White amorphous powder ; UV (MeOH) λmax 197.0; 1H NMR  and 13C NMR data , see Supplementary Table m/z 265.1453 [M - H]− ; (−)-ESIMS m/z 265.25 [M−H]−, ( + )-ESIMS m/z 267.33 [M + H]+.Colorless crystals (EtOAc); [α]20 D =  +58.89 ; UV (MeOH) λmax 193, 243; CD  λ(Δε): 208 (−1.57), 241 (+1.76), 284 (−2.29), 303 (−2.18), 335 (−2.27); 1H NMR  and 13C NMR data , see Supplementary Table m/z 313.1649 [M + COOH]− , (+)-HRESIMS m/z 291.1569 [M + Na]+ .Colorless needles (MeOH); [α]20 D = +4.67 ; UV (MeOH) λmax 198.0, 295.5; CD  λ(Δε): 203.0 (−0.67), 209 (−0.78), 225.0 (−0.14), 245.0 (−0.39), 293.5 (+1.57), 329.0 (−1.51); 1H NMR  and 13C NMR data , see Supplementary Table m/z 251.1637 [M + H]+ ; (−)-ESI-MS m/z 249.25 [M−H]−, (+)-ESI-MS: m/z 251.37 [M + H]+.Colorless oil (EtOAc); 20 D = +55.33 ; UV (MeOH) λmax 197.5, 269.5; CD  λ(Δε): 279.5 (+1.13), 326.5 (−0.91); 1H NMR  and 13C NMR data , see Supplementary Table m/z 267.1589 [M + H]+ ; (−)-ESI-MS m/z 265.19 [M−H]−, (+)-ESI-MS m/z 267.36 [M + H]+.Colorless oil (EtOAc); [α]20 D = −153.85 ; UV (MeOH) λmax 205, 266; CD  λ(Δε): 205 (+2.16), 221 (+4.40), 295 (−3.05), 334 (−0.25); 1H NMR  and 13C NMR data , see Supplementary Table m/z 249.1485 [M + H]+ .Colorless oil (EtOAc); [α]20 D = −160.56 ; UV (MeOH) λmax 198, 231; CD  λ(Δε): 216 (+7.24), 252 (−8.05), 312 (+3.92); 1H NMR  and 13C NMR data , see Supplementary Table m/z 233.1535 [M + H]+ ; (+)-ESI-MS: m/z 233.47 [M + H]+.Colorless oil (EtOAc); -1-methyl pyridinium (APP+) was used to examine SERT activity and the fluorescent dye Hoechst 33342 stain cellular nuclei. The effects of test compounds on SERT function were calculated by the following equation: Relative fluorescent intensity (RFI) = (Intracellular APP+ fluorescent intensity treatment/Intracellular APP+ fluorescent intensity control). The positive control drugs in testing SERT function include SSRI fluoxetine 2.0 μM and SSRE tianeptine 1.0 μM. All test compounds were run in triplicates with three repeat times. The data from the SERT function assays were analyzed by using SPSS software . The RFI values under different treatments were evaluated by one-way analysis of variance (ANOVA), followed by post hoc testing using Dunnett’s multiple comparisons tests. The results were expressed in Mean ± S.E.M.55. Some available compounds were re-purified to make sure their purities ≥95%  before bioactivity evaluation.The SERT activity assay was based on the reported methodSupplementary Information


In each of the title compounds, the cation is conformationally chiral, exhibiting conformational disorder, while two of the nitro groups in the picrate anion also exhibit disorder. In the benzoate salt, the ions are linked into a chain of rings by N—H⋯O hydrogen bonds, whole in the picrate salt, the hydrogen-bonded four-ion aggregate contains four different types of ring. 11H19N2S+·C7H5O2−, (I), and 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium picrate , C11H19N2S+·C6H2N3O7−, (II), the cations are conformationally chiral as the six-membered rings adopt half-chair conformations, which are disordered over two sets of atomic sites giving approximately enantiomeric disorder. For both cations, the bond lengths indicate delocalization of the positive charge comparable to that in an amidinium cation. The bond lengths in the picrate anion in (II) are consistent with extensive delocalization of the negative charge into the ring and onto the nitro groups, in two of which the O atoms are disordered over two sets of sites. In (I), the ionic components are linked by N—H⋯O hydrogen bonds to form a chain of rings, and in (II), the N—H⋯O hydrogen bonds link the components into centrosymmetric four-ion aggregates containing seven hydrogen bonded rings of four different types.In both 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3- benzothiazol-3-ium benzoate, C For an idealized half-chair form the puckering angles are θ = 50.8° and φ = (60k + 30)°, where k represents an integer. In each of (I)Compound (I)if Fig. 1. In the if Fig. 1. The rin2 hydrogen bond, generating two edge-fused rings of Compound (II)es Fig. 3.x3A,Cx4,Cx5,Cx6,Cx7,Cx7A) are Q = 0.444 (10) Å, θ = 41.9 (15)° and φ = 150 (2) when x = 1 and Q = 0.441 (14) Å, θ = 136 (2)° and φ = 328 (3)° when x = 2, so that the ring- puckering parameters are very similar to those found in compound (I)min = (180 − θmaj) and φmin = (180 + φmaj), where min and maj refer to the minor and major components, indicate clearly the approximately enantiomorphic relationship between the two conformers  and 0.425 (4). For the major conformer, the ring-puckering parameters, calculated for the atom sequence  and 1.323 (3) Å respectively in (I)et al., 1987o-quinonoid isomers, and the ketonic form (E) are significant contributors to the overall electronic structure of the anion in addition to the classically delocalized form (C) (see Scheme).In the picrate anion of (II)et al., 1994c-glide plane at y = 0.5 into a The major and minor conformers of the cation in (I)on Fig. 5.2 hydrogen bond, and the hydrogen bonds together generate a four-ion aggregate in which a centrosymmetric In addition, the N—H⋯O hydrogen bonds within the selected asymmetric unit of (II)te Fig. 6. It is net al., 2001trans-bisdichloroplatinum(II), which crystallizes as a tetrakis(dimethylformamide) solvate  for (I)2-Amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazole  and the equivalent amount of the respective acid Crystal data, data collection and structure refinement details are summarized in Table 33) or 0.97 Å (CH2) and N—H = 0.86 Å, and with Uiso(H) = kUeq (C), where k = 1.5 for the methyl groups which were permitted to rotate but not to tilt and 1.2 for all other H atoms. One bad outlier reflection , 0.96 Å −(I−)]/[(I+)+(I−)], and by means of the Hooft y parameter  and y = 0.0561 (8): use of the TWIN/BASF procedure in SHELXL for the determination of the Flack x parameter gave a less well defined value, x = 0.053 (18). In the final analysis of variance for compound (II)oF2)/mean(Fc2)] for the group of 433 very weak reflections having Fc/Fc(max) in the range 0 < Fc/Fc(max) < 0.006.The correct orientation of the structure of (I)10.1107/S2056989017011446/lh5849sup1.cifCrystal structure: contains datablock(s) global, I, II. DOI: 10.1107/S2056989017011446/lh5849Isup2.hklStructure factors: contains datablock(s) I. DOI: 10.1107/S2056989017011446/lh5849IIsup3.hklStructure factors: contains datablock(s) II. DOI: Click here for additional data file.10.1107/S2056989017011446/lh5849Isup4.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989017011446/lh5849IIsup5.cmlSupporting information file. DOI: 1566446, 1566445CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


A chiral methine-C atom connects the (4-chlorophenyl)sulfanyl, benzaldehyde and methoxy residues in the racemic title compound. Supramolecular helical chains are formed in the crystal, being sustained by methyl- and methine-C—H⋯O(carbonyl) interactions. 15H13ClO2S, comprises (4-chlorophenyl)sulfanyl, benzaldehyde and methoxy residues linked at a chiral methine-C atom . A twist in the methine-C—C(carbonyl) bond [O—C—C—O torsion angle = 19.3 (7)°] leads to a dihedral angle of 22.2 (5)° between the benzaldehyde and methine+methoxy residues. The chlorobenzene ring is folded to lie over the O atoms, with the dihedral angle between the benzene rings being 42.9 (2)°. In the crystal, the carbonyl-O atom accepts two C—H⋯O interactions with methyl- and methine-C—H atoms being the donors. The result is an helical supramolecular chain aligned along the c axis; chains pack with no directional interactions between them. An analysis of the Hirshfeld surface points to the important contributions of weak H⋯H and C⋯C contacts to the molecular packing.The title compound, C N,N-diethyl-2-[(4′-substituted)phenylthio]acetamides ° owing to the twist about the C8—C9 bond as seen in the value of the O1—C8—C9—O2 torsion angle of 19.3 (7)°. The 4-chlorophenyl group is orientated so that the ring lies over the oxygen atoms with the dihedral angle between the benzene rings being 42.9 (2)°.The molecular structure of (I)1 symmetry, Fig. 2a. Chains assemble into the three-dimensional architecture without directional interactions between them, Fig. 2b.The molecular packing of (I)et al., 2017A and methine-H8 atoms, a pair near the carbonyl-O2 atom arise as a result of the C—H⋯O interactions leading to the supramolecular chain discussed above, Table 1C atoms are viewed as the pair of diminutive and faint-red spots near these atoms in Fig. 3B, phenyl-C14 and -H14 atoms represent H7B⋯H14 and C⋯H/H⋯C contacts. Views of the Hirshfeld surfaces mapped over electrostatic potential are shown in Fig. 4dnorm-mapped Hirshfeld surface and highlight the intermolecular C—H⋯O interactions and short interatomic H⋯H, C⋯H/H⋯C and C⋯C contacts.The Hirshfeld surface calculations for (I)et al., 2007i.e. 0.6%, contribution from C⋯C contacts as summarized in Table 3de + di ∼ 2.1 Å and the pair of parabolic distributions of points at around de + di < 2.8 Å in their respective delineated fingerprint plots. The short interatomic C⋯H/H⋯C contacts in the crystal, Table 2de + di ∼ 2.7 Å attached to the aforementioned parabolic distribution. The interatomic Cl⋯H/H⋯Cl contacts, making the next most significant contribution to the Hirshfeld surface, i.e. 12.8%, are at van der Waals separations. The C—H⋯O contacts, involving the carbonyl-O2 with methyl-C7 H and methine-C8 H atoms, Table 1de + di ∼ 2.3 Å. The vase-shaped distribution of points beginning at de + di ∼ 3.3 Å in the fingerprint plot delineated into C⋯C contacts results from the contacts highlighted in Fig. 5The non-symmetric molecular geometry in (I)et al., 2010et al., 2011a, clearly indicating their weakly attractive nature. Similarly, the interactions between the chlorobenzene-C6 and methyl-H7C atoms, Fig. 7b, and between the methyl-H7B and phenyl-H14 atoms, Fig. 7c, are weakly attractive.Non-covalent interaction plots are a convenient means by which the nature of a specified intermolecular interaction may be assessed in terms of it being attractive or otherwise –(III) is shown in Fig. 8There are two closely related literature precedents for (I)n-butyllithium  in THF (25 ml). After 30 min., a solution of 4′-chlorophenyl disulfide  with hexamethylphosphoramide (HMPA)  dissolved in THF (15 ml) was added dropwise to the enolate solution , then with dry acetone to give a mixture of both acetophenones (product and reactant). Crystallization was performed by vapour diffusion of n-hexane into a chloroform solution held at 283 K to give pure product . Irregular colourless crystals for X-ray diffraction of (I)1H NMR : 3.67 , 5.86 , 7.24–7.29 , 7.44–7.47 , 7.57–7.60 , 7.93–7.95 . 13C NMR : 190.20, 135.60, 135.25, 134.23, 133.55, 129.22, 128.84, 128.59, 89.37, 56.13. Microanalysis calculated for C15H13ClO2S (%): C 61.53, H 4.48. Found (%): C 61.47, H 4.55. High-resolution MS  calculated: 292.0325, 294.0295; found: 292.0324, 294.0296.The 4′-chlorophenyl disulfide precursor was prepared as previously described  set to 1.2–1.5Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 410.1107/S2056989018006072/hb7746sup1.cifCrystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989018006072/hb7746Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018006072/hb7746Isup3.cmlSupporting information file. DOI: 1838590CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


DGE-Eu) was synthesized from eugenol by a three-step reaction. It consists of a 1,2,4-trisubstituted benzene ring substituted by diglycidyl ether, a methoxy group and a methyloxirane group. The three-membered oxirane rings are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ab plane.The diepoxy monomer benzyl]oxirane}, was synthesized from eugenol by a three-step reaction. It consists of a 1,2,4-trisubstituted benzene ring substituted by diglycidyl ether, a methoxy group and a methyloxirane group. The three-membered oxirane rings are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°. The methylene C atom of one of the two terminal epoxide rings is positionally disordered [refined occupancy ratio = 0.69 (1):0.31 (1)]. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ab plane. The layers are linked by C—H⋯π interactions, forming a three-dimensional network.The diepoxy monomer, C While atoms O1, O2 and C11 lie in the plane of the benzene ring, the methoxy group (O1/C5/C10) is inclined to the benzene ring by 11.2 (3)°. The two oxirane rings (O3/C8/C9 and O4/C12A/C13) are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°, respectively. The molecule shows disorder with an occupation factor equal to 0.69 (1) for the major component of the methylene group (C12A) of the oxirane ring (C11/C12/O3). Such disorder is commonly observed for diglycidyl ether derivatives benzene , according to a three-step procedure previously reported in the literature (Qin Uiso(H) = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms. Atom C12 atom of the epoxypropane (oxirane) group (C11/C12/O3) was found to be disordered over two positions with a refined occupancy ratio of 0.69 (1): 0.31 (1) for atoms C12A:C12B.Crystal data, data collection and structure refinement details are summarized in Table 210.1107/S2056989017005370/su5360sup1.cifCrystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989017005370/su5360Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989017005370/su5360Isup3.cmlSupporting information file. DOI: 1543288CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


Artemisia capillaris Thunberg. The novel compound isofraxidin 7-O-(6′-O-p-coumaroyl)-β-glucopyranoside (compound 1) was isolated and its pigmentation activity was characterized in mammalian melanocytes. Compound 1 stimulated melanin accumulation and increased tyrosinase activity, which regulates melanin synthesis. Moreover, compound 1 increased the expression of tyrosinase and the key melanogenesis regulator microphthalmia-associated transcription factor (MITF) in melanocytes. Compared to the parent compound, isofraxidin, compound 1 produced greater effects on these pigmentation parameters. To validate compound 1 as a novel hyperpigmentation agent in vivo, we utilized the zebrafish vertebrate model. Zebrafish treated with compound 1 showed higher melanogenesis and increased tyrosinase activity. Compound 1 treated embryos had no developmental defects and displayed normal cardiac function, indicating that this compound enhanced pigmentation without producing toxicity. In summary, our results describe the characterization of novel natural product compound 1 and its bioactivity as a pigmentation enhancer, demonstrating its potential as a therapeutic to treat hypopigmentation disorders.Abnormalities in skin pigmentation can produce disorders such as albinism or melasma. There is a research need to discover novel compounds that safely and effectively regulate pigmentation. To identify novel modulators of pigmentation, we attempted to purify compounds from a bioactive fraction of the Korean medicinal plant Human skin is exposed to numerous environmental stresses, such as mutagenic ultraviolet radiation. Mutations or dysregulation of the genes that regulate pigmentation can produce hypopigmentation disorders, such as albinism or vitiligo , 2. HypoSmall molecule compounds that increase melanin synthesis have the potential to treat hypopigmentation disorders . Numerou Artemisia capillaris Thunberg . The Artemisia genus has been used as a herbal medicine for a range of disorders, including inflammation, microbial infections, cancer, and malaria . The chemical shifts (δ) were expressed as parts per million (ppm) and the coupling constants (J) were expressed in Hz. Mass spectra were measured on a JMS-700  and Varian 1200, Platform II  spectrometers. High resolution mass (ESI-MS) and LCMS/MS spectra were measured with a Waters Synapt High Definition Mass Spectrometry/time-of-flight mass spectrometer, using the negative electrospray ion mode.Optical rotation was measured with a JASCO DIP-1000 digital polarimeter. UV spectra were recorded with a JASCO V-530 UV/Vis spectrophotometer  and IR spectra were obtained using a JASCO FT/IR-300E spectrometer .  Artemisia capillaris Thunberg was provided by Professor Soon-Ho Yim, Dongshin University, Jeonnam, Republic of Korea.The active fraction (ACMF09) from L-3,4-dihydroxyphenylalanine (L-DOPA), caffeine powder, staurosporine, 3--2,5-diphenyltetrazolium bromide (MTT), and CellLytic™ lysis buffer were purchased from Sigma . Isofraxidin was purchased from ChemFaces Biochemical .IBMX, forskolin, phenylthiourea (PTU), sodium hydroxide (NaOH), DMSO,2.Murine melanoma B16F10 melanocytes were supplied by the American Type Culture Collection  and cultured in DMEM containing 10% FBS and 1% penicillin-streptomycin mixture . Cells were cultured in a 37°C humidified incubator with 5% CO5 cells/well. 24 h later, the cells were treated with compound of interest for 48 h. Cells were washed with PBS and lysed with 4°C CellLytic buffer, followed by centrifugation at 13000 rpm for 10 min at 4°C. The pellet was used for melanin content analysis by two washes with ethanol : ether (1 : 1 volume) and dissolving in 200 μL 1 N NaOH containing 10% DMSO, with heating at 80°C for 1 h. 100 μL aliquots of the solution were measured for melanin content by reading the absorbance at 400 nm using a microplate reader , as previously described.The melanocytes were seeded in a 6-well plate at a density of 2 × 104 cells/well using 500 μL culture media. 24 h later, the culture media were replenished and cells were treated with the compound of interest for 60 h. The culture media were collected and melanin levels were measured at an absorbance wavelength of 475 nm using a microplate reader .Based on the previously published protocol . B16F10 5 cells/well. 24 h later, the cells were treated with compound of interest for 48 h. The cells were rinsed with PBS and lysed with CellLytic buffer at 4°C. Cell extracts were then centrifuged at 13000 rpm for 10 min at 4°C. The protein concentration was adjusted using the Bradford assay and 100 μL lysate containing 40 μg protein was transferred into a 96-well plate. 100 μL of 5 mM L-DOPA was added, followed by incubation at 37°C for 60 min. Dopachrome formation was measured at 475 nm with a plate reader.Tyrosinase activity in the compound treated melanocytes was measured as previously described . In brieμL of 50 mM potassium phosphate and 50 μL of the mushroom tyrosinase solution were combined with the test samples in a microfuge tube and incubated for 5 min at room temperature. 100 μL of 1.5 mM L-tyrosine was added and the solution was transferred to a 96-well plate. Formation of the dopachrome product was determined by measuring the absorbance at 490 nm using a microplate reader.The effect of the compounds on mushroom tyrosinase activity was measured using the assay of Zhang et al.  with the A. capillaris was separated using a RP-18 column with a gradient of H2O-MeOH (60 : 40 v/v) for 50 min and then changed to 0 : 100 for 20 min to yield compound 1 (2 mg). The active fraction of the MeOH extract ofIsofraxidin 7-O-(6′-O-p-Coumaroyl)-β-glucopyranoside. Brownish amorphous powder; UV λmax (H2O) (logε) 300, 304, 322 nm; IR (KBr) νmax: 3500, 1675, 1011 cm−1; 1H NMR δ 7.64 , 7.37 , 7.32 , 6.90 , 6.80 , 6.16 , 6.10 , 5.20 , 4.39 , 4.34 , 3.99 , 3.88 , 3.55 , 3.50 , 3.47 , 3.40 ; 13C NMR  δ 168.7 (C-9′′), 162.7 (C-2), 161.5 (C-4′′), 151.8 (C-6), 146.5 (C-7′′), 145.7 (C-4), 144.0 (C-8a), 143.1 (C-7), 142.7 (C-8), 131.3 (C-2′′/C-6′′), 127.1 (C-1′′), 117.1 (C-3′′/C-5′′), 116.9 (C-4a), 115.7 (C-3), 114.9 (C-8′′), 105.9 (C-5), 103.9 (C-1′), 77.9 (C-3′), 75.9 (C-5′), 75.7 (C-2′), 72.2 (C-4′), 64.4 (C-6′), 62.5 (8-OMe), 57.2 (6-OMe); HRESI-MS m/z 529.1346 [M−H]− (C26H25O12).μg RNA using AccuPower® PCR PreMix (Bioneer) following the manufacturer's recommendation. mRNA expression of the MITF gene, tyrosinase gene, and TRP-1 was quantified using a Power SYBT® Green PCR Master Mix (Applied Biosystems). mRNA levels were normalized with β-actin and fold change of expression was calculated with the ΔΔCT method. The primer sequences were as follows: mouse tyrosinase forward 5′-TACTTGGAACAAGCCAGTCGTATC-3′, reverse 5′-ATAGCCTACTGCTAAGCCCAGAGA-3′; mouse TRP-1 forward 5′-AAACCCATTTGTCTCCCAATGA-3′, reverse 5′-CGTTTTCCAACGGGAAGGTA-3′; mouse MITF forward 5′-GGACTTTCCCTTATCCCATCCA-3′, reverse 5′-GCCGAGGTTGTTGGTAAAGGT-3′. The PCR conditions were 95°C for 2 min followed by 40 cycles of 95°C for 30 s, 60°C for 1 min, and 72°C for 1 min followed by a final 30 sec extension at 72°C. Data were analyzed using the Stepone™ software v2.3 (Applied Biosystems).B16F10 melanocytes were treated with test compounds for 48 h. Total RNA was extracted using the TRI-Solution™ according to the manufacturer's instructions and quantified using a NanoDrop 2000 spectrophotometer (NanoDrop Technologies). cDNA synthesis was carried out from 1 3 cells/well for 12 h. Cells were treated with compound or extract for 48 h.Cell viability was assessed using the MTT assay, as previously described . B16-F10 (Danio rerio) were purchased from a commercial outlet . 10–15 fishes were maintained in a 5 L acrylic tank under the following conditions: water temperature 28.5°C with a 14/10 h light/dark cycle. Zebrafish were fed twice daily with live brine shrimps . Fish breeding was carried out using the standard protocol [The experimental protocols involving zebrafish were approved by the Animal Care and Use Committee of the Gwangju Institute of Technology, Republic of Korea. All methods that utilized zebrafish were carried out in accordance with relevant guidelines and regulations provided by the Gwangju Institute of Science and Technology. Adult zebrafishprotocol  at 9.30 2 Petri dishes using embryo media  at a density of 70–80 embryos/dish. For compound treatment, embryos were placed in a 96-well plate (3 embryos/well in 200 μL embryo media). Compounds were dissolved in 0.1% DMSO and embryos were treated from 9 to 72 hpf (63 h exposure). The media and embryos were gently stirred and media/compound was replenished daily to ensure an even compound distribution. Effects on the pigmentation were imaged by stereomicroscopy . In all experiments, 75 μM PTU was used as a positive control to ablate zebrafish pigmentation without interfering with developmental processes [Zebrafish embryos were maintained in 100 mmμL buffer). The lysate was centrifuged at 13000 rpm for 10 min. the supernatant was collected and protein was quantified using the Bradford assay. 250 μg total protein in 100 μL buffer was transferred to a 96-well plate. 100 μL 5 mM L-DOPA was added, followed by incubation for 60 min at 37°C. The absorbance was determined at 475 nm using a microplate reader. The blank sample reading was deleted from each absorbance value, with the final activity expressed as a percentage of the water control.Tyrosinase activity was measured as described previously  with theμL 1 N NaOH with 10% DMSO for 80°C for 60 min, followed by vortexing. Absorbance was measured at 400 nm using a microplate reader.Melanin content in the zebrafish was measured using the previously described protocol . In brieTo determine the toxicity of test compounds, the heart rate of the atrium and ventricle was measured for 3 min at 48 hpf to assess toxicity, as previously described  using a To count melanocytes, embryos were exposed to the fish room lighting. This induces contraction of the melanin within the melanocytes . Embryos t-test (Microsoft Excel 2016). A p value of less than 0.05 was considered to be significant. Data are expressed as the means ± SEM of three independent experiments, unless otherwise indicated.Data were evaluated for significance using Student's A. capillaris was previously shown to regulate melanin synthesis [ 1; Figures  1 extracted with a retention time 54.428 min is shown in  1 was identified and characterized on the basis of complementary information provided by ESI-MS detectors. The structure of the isolate was identified by spectroscopic analysis (1H NMR), as a novel compound. The IR and UV spectra for purified compound 1 are shown in Figures  1 was a pale brown, amorphous powder. Compound 1 was assigned the molecular formula, C26H25O12, based on the HRESIMS spectra of the compound obtained in the negative ion mode . Compound 1 exhibited UV absorption bands at 300, 304, and 322 nm with IR absorption bands corresponding to hydroxy (3500 cm−1) and carbonyl (1675 cm−1). The 1D NMR spectra of compound 1 exhibited signals for a coumarin moiety, a p-coumaroyl moiety, and a β-glucopyranose unit. Compound 1 showed two doublets at δH 7.64 , δH 6.16 , and a carbonyl ester at δC 162.7 (C-2) ascribable to the coumarin moiety and exhibited the presence of one β-glucopyranose unit from the anomeric signals at δH 5.20  including hydroxyl methine signals at δH 3.40~3.55 with vicinal coupling constants (J = 9.0 Hz) between two axial hydrogens. The signals of p-coumaroyl moiety were assigned to symmetric doublets at δH 7.32  and 6.80 , as well as proton doublets showing trans-configuration at δH 7.37  and 6.10 . Two aromatic carbon signals at δC 161.5 (C-4′′) and 127.1 (C-1′′) were correlated to two symmetric doublet proton signals and proton doublets with trans-configuration of p-coumaroyl moiety in the heteronuclear multiple bond connectivity (HMBC) spectrum. In addition, long-range HMBC correlations were, respectively, observed between anomeric proton (H-1′) and an oxygenated aromatic carbon at δC 143.1 (C-7), between a methoxy proton signal at δH 3.88  and C-6 carbon and a methoxy proton signal at δH 3.99  to C-8 aromatic carbon  and δC 64.4 (C-6′) indicated that a carbonyl ester (C-9′′) group of p-coumaroyl moiety was attached with C-6′ of the glucose unit. On the basis of this data, the structure of compound 1 was elucidated to be isofraxidin 7-O-(6′-O-p-coumaroyl)-β-glucopyranoside. The 1H and 13C NMR spectroscopic data  for compound 1 are shown in An active fraction fromynthesis . Preparac carbon . Moreove 1 regulates melanogenesis, melanin levels in B16F10 cells were measured after compound treatment. Along with compound 1, we also tested the effects of isofraxidin , the parent compound of compound 1. The previously characterized melanogenic inhibitor, azelaic acid (AZ) [ 1 to melanocytes stimulated melanin production  , was use Figures . Compount manner . Moreovet manner . The part manner . 1 treatment increased melanin secretion by the melanocytes , tyrosinase-related protein-1 (TRP-1), and tyrosinase , 26, 27. Figures . The inc 1 on pigmentation in vivo, we employed the zebrafish larvae model, which has proved useful for characterizing novel regulators of pigmentation [To assess the effect of compoundentation . Phenyltentation , was tesWe found out that PTU dose-dependently abrogated pigmentation . 1  relative to isofraxidin (Figures  1 increased the activity of tyrosinase in the cell-free assay, which was not observed after isofraxidin treatment ( 1 increased melanocyte number and area (Figures  1 produced significant increases in melanocyte accumulation and tyrosinase activity in this animal model (Figures  1 is a more potent inducer of pigmentation compared to isofraxidin.Compound Figures . To our  Figures . However Figures . In cont Figures . A poten Figures . In addireatment . In the  Figures . However Figures  indicati 1 is a novel, nontoxic pigmentation enhancer that is effective in vivo. Compound 1 targets the expression of MITF and tyrosinase expression/activity. These results indicate that this natural product can be further developed as a therapeutic for treating hypopigmentation disorders.In summary, we have discovered that compound


The galactoside molecules are connected by several O—H⋯O hydrogen bonds, forming a sheet lying parallel to (100), and by intermolecular C—H⋯O interactions.The pyranoid ring of the title compound C 14H19NO8·H2O, prepared in three steps from 6-O-ethyl-1,2;3,4-di-O-isopropylidene-α-d-galactopyranose using protecting-group strategies employed in carbohydrate chemistry, is reported. The asymmetric unit consists of a single galactoside molecule, in which the pyranoid ring has a 4C1 conformation and the 4-nitrophenyl moiety is essentially planar. In the crystal, each carbohydrate is surrounded by other d-galactose residues and water molecules, linked by O—H⋯O hydrogen bonds involving all hydroxy groups, giving a two-dimensional substructure lying parallel to (100) and extended into three dimensions by C—H⋯O interactions.The synthesis and crystal structure of the title compound, C The anomeric beta form and d-galacto configuration of the carbohydrate with C1(S), C2(R), C3(S), C4(R) and C5(R) are consistent with that expected from the synthesis. The length of the glycosidic bond is 1.408 (2) Å and the bond angles around the anomeric carbon atom (C1) range from 106.40 (16) to 111.35 (17)°. The 4-nitrophenyl substituent at C1 located in an equatorial position is essentially planar, with a r.m.s. deviation of 0.02 Å for non-hydrogen atoms [torsion angle C9—C10—N1—O11 = 179.0 (4)°]. The angle between the mean plane of the 4-nitrophenyl substituent (defined by atoms C7–C12/N1/O11/O12) and the mean sugar plane (defined by C1–C5/O5 atoms) is 57.45 (11)° [torsion angle O5—C1—O1—O7 = −79.8 (2)°]. An intramolecular C13—H13B⋯O5 interaction is also present (Table 1In the structure of the title monohydrated compound (I)t Table 1.d-galactose residues by several direct and water-mediated classical hydrogen bonds ° in the title compound. According to the authors A⋯O12 interaction noted above.To the best of our knowledge, this is the first report of the crystal structure of an aryl 6-O-ethyl-β-d-galactopyranoside monohydrate (I)The chemical synthesis of 4-nitrophenyl 6-O-alkylation of 1,2;3,4-di-O-isopropylidene-α-d-galactopyranose was carried out as reported in the literature furnishing the 6-O-alkylated derivative (2)  was prepared in a three-step one-pot reaction as follows. To a solution of (2)  in acetyl chloride  was added methanol (0.42 mL) under ice-bath conditions. The mixture was stirred at room temperature for 2h in a closed system and concentrated hydrochloric acid (0.34 mL) was then added and the resulting mixture was stirred at room temperature for 24 h, also in a closed system. The reaction was quenched with crushed ice (about 30 mL) and the mixture was extracted with dichloromethane (3 × 25 mL). The organic layers were washed with a saturated aqueous sodium bicarbonate solution (2 × 60 mL) and water (60 mL), then dried over anhydrous sodium sulfate and concentrated. The brown oil obtained  was used in the next step without further purification.Initially the et al., 19573) in alkaline medium gave (4) in 46% yield. Treatment with sodium methoxide to remove the acetyl groups furnished (I)Classical procedures in carbohydrate chemistry were employed in the next two steps . IR max (cm−1): 3354 (O—H), 1608, 1592, 1493 (C=C), 1511, 1349 (NO2), 1249, 1074 (C—O), 846 (C—H aromatic out-of-plane bending). 1H NMR : δH 8.20 , 7.22 , 5.28 , 5.05 , 4.91 , 4.64 , 3.85 , 3.71–3.66 , 3.63 , 3.55 , 3.50–3.39 , 1.09 . 13C NMR : δC 162.4 (OCCH), 141.6 (CHCNO2), 125.6 (CHCNO2), 116.5 (OCCH), 100.3 (C-1), 73.8 (C-5), 73.0 (C-3), 70.0 (C-2), 69.1 (C-6), 68.3 (C-4), 65.7 (O2CHCH3), 15.1 (OCH23CH).Spectrometric data. [α]Uiso(H) = 1.5 Ueq(O). Carbon-bound H atoms were constrained to an ideal geometry with C—H distances in the range 0.93–0.98 Å, Uiso(H) = 1.5 Ueq(C) for methyl H atoms and Uiso(H) = 1.2 Ueq(C) for other H atoms. In the absence of significant anomalous scattering effects, the Flack structure parameter  I. DOI: 1539718CCDC reference:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


T, was obtained from an anaerobic batch digester treating animal manure and rice straw. Cells were Gram-stain-positive, slightly curved rods with a size of 0.6–1×2.5–8.2 µm, non-motile and produced terminal spores. The temperature, pH and NaCl concentration ranges for growth were 40–60 °C, 6.5–8.0 and 0–15.0 g l−1, with optimum growth noted at 50–55 °C, pH 7.5 and in the absence of NaCl, respectively. Yeast extract was required for growth. d-Glucose, maltose, d-xylose, d-galactose, d-fructose, d-ribose, lactose, raffinose, sucrose, d-arabinose, cellobiose, d-mannose and yeast extract were used as carbon and energy sources. The fermentation products from glucose were ethanol, lactate, acetate, propionate, butyrate, valerate, iso-butyrate, iso-valerate, H2 and CO2. The G+C content of the genomic DNA was 36.6 mol%. The predominant fatty acids were C16 : 0, iso-C17 : 1, C14 : 0, C16 : 1ω7c, C16 : 0 N-alcohol and C13 : 0 3-OH. Respiratory quinones were not detected. The polar lipid profile comprised phosphoglycolipids, phospholipids, glycolipids, a diphosphatidylglycerol, a phosphatidylglycerol and an unidentified lipid. Phylogenetic analyses of the 16S rRNA gene sequence indicated that the strain was closely related to Defluviitalea saccharophila DSM 22681T with a similarity of 96.0 %. Based on the morphological, physiological and taxonomic characterization, strain A6T is considered to represent a novel species of the genus Defluviitalea, for which the name Defluviitalea raffinosedens sp. nov. is proposed. The type strain is A6T (=DSM 28090T=ACCC 19951T).A thermophilic, anaerobic, fermentative bacterium, strain A6 It compigesters . It is wronments . Defluviy Jabari  to descrClostridium, Gracilibacter, Sedimentibacter and uncultured Firmicutes were the predominant organisms of the microbial consortium (unpublished data). To reveal the ecophysiological roles of anaerobic bacteria in anaerobic digestion, strain A6T was enriched and isolated from the above-mentioned microbial consortium at 55 °C using enriched medium . The basal medium contained the following (per litre distilled water): NH4Cl, 1.0 g; yeast extract, 0.1 g; l-Cys-HCl, 1 g; 0.1 % (w/v) resazurin solution, 1.0 ml; macro mineral solution, 50.0 ml; trace mineral solution, 10.0 ml; and vitamin mix solution, 10.0 ml. The macro mineral solution, trace mineral solution and vitamin mix solution were prepared as described previously [2. The pH of the medium was adjusted to 6.5–7.0 with 5 M KOH, and the media were sterilized by autoclaving at 121 °C for 30 min.We collected samples from an anaerobic batch digester treating animal manure and rice straw, which was pre-enriched with PY medium (2 g peptone and 1 g yeast extract per litre distilled water) containing rice straw (5 g per litre distilled water), and a microbial consortium degrading rice straw under anaerobic methanogenic conditions at 40 °C was obtained and subcultured for 10 years. The 16S rRNA clone libraries and high-throughput sequencing analyses revealed that eviously . The agaT. This strain did not utilize acetate or propionate, but grew at low cell concentration in enriched medium, indicating that the yeast extract in the medium served as carbon and energy source during enrichment and isolation. For subsequent incubation of strain A6T, d-glucose was used as the main substrate, instead of acetate or propionate. The taxonomic description of strain A6T is reported here based on phenotypic and phylogenetic studies.The enriched medium was inoculated with 2 % (v/v) rice-straw-degrading microbial consortium and incubated for 1 week at 55 °C. For isolation, the enrichment culture was serially diluted tenfold in Hungate tubes containing molten agar medium, and the tubes were rolled following the procedures of the Hungate roll-tube technique . Subsequblastn program. The 16S rRNA sequences from closely related organisms were retrieved from NCBI and EzTaxon. Phylogenetic trees were reconstructed with the software package mega version 5.0 using the neighbour-joining and maximum-likelihood methods [T belonged to the family Defluviitaleaceae, and that its closest relative was D. saccharophila LIND6LT2T (96 % sequence similarity), followed by Natranaerovirga pectinivora AP3T (88.9 %), Vallitalea guaymasensis Ra1766G1T (88.4 %), Lactonifactor longoviformis ED-Mt61/PYG-s6T (88.3 %) and Anaerostipes butyraticus LMG 24724T (88.11 %)  .T were investigated using cells cultivated on basal carbonate yeast extract and trypticase medium (BCTY medium). The BCTY medium consisted of basal medium, yeast extract (0.5 g l−1) and trypticase (0.5 g l−1). Prior to inoculation, filter-sterilized glucose solution was added as substrate  to the sterile BCTY medium. Cell morphology was examined using a scanning electron microscope (JEOL JSM-7500F) and transmission electron microscope (Hitachi H-600IV). Gram staining was performed using the traditional method [The cultural and morphological characteristics of the isolated strain A6l method  and sporl method . The preD. saccharophila DSM 22681T was obtained from the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ) for comparson of its physiological and chemotaxonomic characteristics with those of strain A6T. Growth experiments to determine the pH, temperature and NaCl concentration ranges were performed in triplicate using Hungate tubes with 5 ml of BCTY medium containing glucose as the substrate. The pH range examined for growth was 5.5–10.0, and was adjusted using the following sterile anaerobic solutions (20 mM): MES , PIPES , HEPES (8.0), Tricine (8.5) and CHES . The temperature range investigated was 35–65 °C at 5 °C intervals, and the NaCl concentration range was 0–25.0 g NaCl l−1. Substrate utilization tests were performed in basal medium with d-glucose, d-xylose, maltose, d-fructose, d-galactose, d-ribose, d-sucrose, d-lactose, d-mannose, d-mannitol, raffinose, l-rhamnose, cellobiose, d-arabinose, yeast extract, acetate, propionate, pyruvate and lactate. Each substrate was added at a final concentration of 20 mM (for sugars and organic acids). The strain was subcultured at least twice under the same experimental conditions prior to determination of growth rates. Elemental sulfur , sulfate (20 mM), thiosulfate (20 mM), sulfite (2 mM), nitrate (10 mM) and nitrite (2 mM) were tested as terminal electron acceptors. Growth was determined by measuring the turbidity of the cultures at a wavelength of 600 nm using a spectrophotometer  as described previously [eviously .2 as the carrier gas at a flow rate of 36 ml min−1. H2 and CO2 were analysed by GC (Agilent 7820A) using a porapak Q packed column (2 m×30 µm) and thermal conductivity detector with N2 as the carrier gas at a ﬂow rate of 30.0 ml min−1 and column temperature of 80 °C. H2S production was determined photometrically as described by Cord-Ruwisch [2CO3 and 0.3 mM NaHCO3 as eluent at a flow rate of 1.2 ml min−1.The liquid fermentation products were determined by GC (Agilent 7890A) using an FFAP column (30 m×320 µm×0.25 µm) and a ﬂame ionization detector with N-Ruwisch . SulfateT formed white and round colonies after 2 days at 55 °C. Cells were non-motile and slightly curved rods with a size of 2.5–7.6×1–0.58 µm, occurring singly or in pairs . The DNA G+C content was determined by using HPLC as described by Mesbah et al. . The celet al. . Fatty aet al. , followe [et al. .T were C16 : 0 (30.6 %), iso-C17 : 1 (30.3 %), C14 : 0 (18.1 %), C16 : 1ω7c (5.6 %), C16 : 0 N-alcohol (3.2 %), C13 : 0 3-OH (2.9 %), C13 : 1 AT 12–13 (1.0 %), C18 : 0 (0.8 %), C12 : 0 (0.7 %), C18 : 1ω7c (0.4 %), C16 : 1ω5c (0.3 %), C18 : 1ω9c (0.3 %) and an unknown component (5.7 %)  [The major whole-cell fatty acids of strain A6 (5.7 %) . RespiraT was found to be phenotypically comparable to D. saccharophila LIND6LT2T with respect to cell morphology, optimum pH and temperature for growth, electron acceptors, and polar lipid profile, it differed with respect to major cellular fatty acids and substrate utilization. Unlike D. saccharophila LIND6LT2T, strain A6T did not ferment d-mannitol or l-rhamnose, but fermented d-galactose, d-fructose, d-ribose, lactose, raffinose and d-arabinose .d-glucose, maltose, d-xylose, d-galactose, d-fructose, d-ribose, lactose, d-mannose, raffinose, sucrose, d-arabinose, cellobiose and yeast extract. Yeast extract is required for growth. The major cellular fatty acids are C16 : 0, iso-C17 : 1, C14 : 0, C16 : 1ω7c, C16 : 0 N-alcohol and C13 : 0 3-OH. Respiratory quinones are not found. The polar lipids are phosphoglycolipids, phospholipids, glycolipids, a diphosphatidylglycerol and a phosphatidylglycerol.Cells are Gram-stain-positive, slightly curved rods with a size of 2.5–7.6×1–0.58 µm, non-motile, occur singly or in pairs, and form spores at high temperature. Growth occurs at 40–65 °C (optimum 50 °C), pH 6.5–8.0 (optimum 7.5) and an NaCl concentration of 0–20 % (w/v). Cells are thermophilic and anaerobic, and hydrolyse T (=DSM 28090T=ACCC 19951T), isolated from an anaerobic batch digester treating animal manure and rice straw. The G+C content of the genomic DNA of the type strain is 36.6 mol%.The type strain is A6


The title compounds show different conformations in the solid state. E)-1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-benzyloxime, C12H12N4O3, (I), (E)-1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-(4-fluorobenzyl) oxime, C12H11FN4O3, (II), and (E)-1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-(4-bromobenzyl) oxime, C12H11BrN4O3, (III), are described. The dihedral angle between the ring systems in (I) is 49.66 (5)° and the linking Nm—C—C=N (m = methylated) bond shows an anti conformation [torsion angle = 175.00 (15)°]. Compounds (II) and (III) are isostructural [dihedral angle between the aromatic rings = 8.31 (5)° in (II) and 5.34 (15)° in (III)] and differ from (I) in showing a near-syn conformation for the Nm—C—C=N linker , which allows for the occurrence of a short intramolecular C—H⋯N contact. In the crystal of (I), C—H⋯N hydrogen bonds link the molecules into [010] chains, which are cross-linked by very weak C—H⋯O bonds into (100) sheets. Weak aromatic π–π stacking interactions occur between the sheets. The extended structures of (II) and (III) feature several C—H⋯N and C—H⋯O hydrogen bonds, which link the molecules into three-dimensional networks, which are consolidated by aromatic π–π stacking interactions. Conformational energy calculations and Hirshfeld fingerprint analyses for (I), (II) and (III) are presented and discussed.The crystal structures of ( Trypanosoma brucei) and Chagas’ disease. The infectious agent of Chagas’ disease is the protozoan parasite Trypanosoma cruzi, which produces progressive symptoms from mild swelling to intestinal disease and ultimately heart failure -1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-benzyloxime, C12H12N4O3 (I)E)-1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-(4-fluorobenzyl) oxime C12H11FN4O3 (II)E)-1-methyl-5-nitro-1H-imidazole-2-carbaldehyde O-(4-bromobenzyl) oxime, C12H11BrN4O3 (III)We have recently described , −172.50 (15) and 172.62 (14)°, respectively. The major twist in the molecule of (I)C = 2.12 Å) is still present.Compound (I)P21/n with one molecule in the asymmetric unit C⋯N3 hydrogen bond in both (II)Compounds (II)t Figs. 2 and 3 ▸.Orca software package version 4.0.0.2 syn conformer arbitrarily defined to be zero in each case) either in vacuo or in a methanol solvent environment, although the differences in the latter case are quite small.The different conformations of (I)C(6) chains, with adjacent molecules related by the 21 screw axis  and 4.1184 (10) Å; corresponding slippages = 1.35 and 2.25 Å, respectively].In the crystal of (I)is Fig. 4. The C5—C⋯Br1 bond in (III)There are a number of intermolecular interactions in (II)CrystalExplorer17  are the most significant in each structure, followed by O⋯H/H⋯O contacts. It is interesting the percentage of the latter for (I)X—H/H⋯X contributions for (II)Hirshfeld surface fingerprint plots for (I)anti conformation in the crystal: it allows the C5—H5 group to form a weak hydrogen bond (Table 1i.e. pointing away from C4) in both (II)syn conformation for (II)X  interactions in the crystals of (II)m—C—C=N grouping has a syn conformation but with a different overall packing motif to (II)Beyond a vague appeal to ‘packing forces’, we find it difficult to explain why (I)d Table 1 to a nitet al., 2016N-[(4-methylbenzyl)oxy]-1-(1-methyl-5-nitro-1H-imidazol-2-yl)methanimine (refcode: TEVGAF), has been reported by Carvalho et al. (2017m—C—C=N torsion angle is −30.7 (2)°, i.e. somewhat twisted from syn.A survey of of the Cambridge Structural Database  = 1.2Ueq(carrier) or 1.5Ueq(methyl carrier) was applied in all cases. The methyl groups were allowed to rotate, but not to tip, to best fit the electron density.Crystal data, data collection and structure refinement details are summarized in Table 610.1107/S2056989018002876/mw2136sup1.cifCrystal structure: contains datablock(s) I, II, III, global. DOI: 10.1107/S2056989018002876/mw2136Isup2.hklStructure factors: contains datablock(s) I. DOI: Click here for additional data file.10.1107/S2056989018002876/mw2136Isup5.cmlSupporting information file. DOI: 10.1107/S2056989018002876/mw2136IIsup3.hklStructure factors: contains datablock(s) II. DOI: Click here for additional data file.10.1107/S2056989018002876/mw2136IIsup6.cmlSupporting information file. DOI: 10.1107/S2056989018002876/mw2136IIIsup4.hklStructure factors: contains datablock(s) III. DOI: Click here for additional data file.10.1107/S2056989018002876/mw2136IIIsup7.cmlSupporting information file. DOI: 10.1107/S2056989018002876/mw2136sup8.pdfSupplementary Figures 1, 2 and 3: Hirshfeld fingerprint plots. DOI: 1486983, 1486982, 1486987CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information:


The conformation of the title diaminopyrimidine sulfanly acetamides, (I) and (II), have similar conformations, with the pyrimidine ring being inclined to the pyridine ring in (I) by 71.10 (9) °, and by 62.93 (15) ° to the pyrazine ring in (II). 11H12N6OS (I) and C10H11N7OS (II), the diaminopyrimidine ring makes dihedral angles of 71.10 (9)° with the pyridine ring in (I) and 62.93 (15)° with the pyrazine ring in (II). The ethanamine group, –CH2–C(=O)–NH– lies in the plane of the pyridine and pyrazine rings in compounds (I) and (II), respectively. In both compounds, there is an intramolecular N—H⋯N hydrogen bond forming an S(7) ring motif and a short C—H⋯O interaction forming an S(6) loop. In the crystals of both compounds, molecules are linked by pairs of N—H⋯N hydrogen bonds, forming inversion dimers with R22(8) ring motifs. In (I), the dimers are linked by N—H⋯O and N—H⋯N hydrogen bonds, forming layers parallel to (1In the title compounds, C Because of the limited capacity of drugs that can cure cancer, there is always an urgent requirement for new chemotherapeutics. 2,4-Diaminopyrimidine derivatives combined with arylthiazole derivatives have shown to possess significant anti-proliferation properties against breast cancer cell lines  ring motif and a short C—H⋯O interaction forming an S(6) loop; see Tables 1Database survey).The molecular structure of compounds (I)B⋯N4i hydrogen bonds, forming inversion dimers with The crystal packing in compound (I)A⋯O1iii hydrogen bonds, forming ribbons along [010], enclosing A⋯N6ii hydrogen bonds, forming sheets lying parallel to the (1Cg⋯Cgv = 3.777 (1) Å, interplanar distance = 3.483 (1) Å, slippage = 1.459 Å, Cg is the centroid of the pyridine ring (N6/C7–C11); symmetry code: (v) −x + 1, −y, −z + 1)].In the crystal of (I)A⋯Oii, N2—H2A⋯N7iii and C9—H9⋯O1iv hydrogen bonds s Table 2, formings Table 2. In contet al., 2016et al., 2017aet al., 2016et al., 2016et al., 2014et al., 2017aet al., 2017et al., 2017et al., 2017bet al., 2017bA search of the Cambridge Structure Database In these eight compounds, the diaminopyrimidine and benzene rings are inclined to one another by dihedral angles varying from dnorm on the molecular Hirshfeld surfaces, where the red-spot areas denote intermolecular contacts involved in the hydrogen-bonding interactions  To a solution of 4, 6-diamino-pyrimidine-2-thiol  in 25 ml of ethanol,  potassium hydroxide was added and refluxed for about 30 min. Then an equimolar quantity of 2-chloro-N-(pyridin-2-yl)acetamide (3.52 mmol) was added to the above reaction mixture and it was refluxed for 5 h. Evaporation of the organic layer under vacuum provided compound (I)Compound (II): To a solution of 4, 6-diamino-pyrimidine-2-thiol  in 25 ml of ethanol,  potassium hydroxide was added and refluxed for about 30 min. Then an equimolar quantity of 2-chloro-N-(pyrazin-2-yl)acetamide (3.52 mmol) was added to the above reaction mixture and it was refluxed for 5.5 h. Evaporation of the organic layer under vacuum resulted in compound (II)2 and NH H atoms were located in difference-Fourier maps and freely refined, and the C-bound H atoms were placed in calculated positions and refined in the riding model: C—H = 0.93–0.97 Å with Uiso(H) = 1.2Ueq(C).Crystal data, data collection and structure refinement details are summarized in Table 310.1107/S2056989018005704/su5430sup1.cifCrystal structure: contains datablock(s) global, I, II. DOI: 10.1107/S2056989018005704/su5430Isup4.hklStructure factors: contains datablock(s) I. DOI: 10.1107/S2056989018005704/su5430IIsup5.hklStructure factors: contains datablock(s) II. DOI: Click here for additional data file.10.1107/S2056989018005704/su5430Isup4.cmlSupporting information file. DOI: Click here for additional data file.10.1107/S2056989018005704/su5430IIsup5.cmlSupporting information file. DOI: 1836419, 1836418CCDC references:  crystallographic information; 3D view; checkCIF reportAdditional supporting information: