Synthesis, characterization and anti-inflammatory properties of karanjin (Pongamia pinnata seed) and its derivatives.
Karanja (Pongamia pinnata) is a medicinal tree used in the Indian traditional ayurvedic system for treating several ailments. The seeds contain a unique furano-flavonoid karanjin, which has shown to possess many medicinal properties. Its usage at the clinical level is affected due to poor solubility and absorption. In the present investigation, molecular modifications of karanjin were attempted and evaluated their effect on anti-inflammatory activity. Firstly, Karanja ketone was obtained from karanjin by hydrolysis, and it was converted into karanja ketone oxime. The oxime undergoes Beckmann rearrangement and cyclized to yield furano benzoxazole (karanja oxazole). The new derivatives were purified with >95% purity (HPLC) and spectrally characterized (HR-MS, FTIR, and NMR). Among the test compounds, karanja ketone oxime exhibited higher antioxidant activity with an IC50 value of 360 µg/ml (DPPH). Soy lipoxygenase-1 (LOX-1) inhibitory activity of oxime was higher (IC50 = 65.4 µM) than other compounds. Fluorescence studies showed that oxime had higher quenching capacity with a Qmax of 76.3% and a binding constant of 0.9 × 105 M-1 for soy LOX-1. In-silico interaction studies showed that karanja ketone oxime had the least binding energy of -5.76 kcal/mol with LOX-1 by forming two hydrogen bonds with hydrophobic amino acids Leu 390 and Gly 392. The compounds were evaluated for their acute anti-inflammatory activity by the paw and ear edema in the rat model. Karanjin inhibits paw edema and ear edema by 34.13% and 51.13%, respectively, whereas the derivatives inhibited by 45-57 % and 70-76.8%. This study reports a rational approach to synthesize karanjin derivatives with considerable anti-inflammatory properties, both in-vitro and in-vivo.
['Rekha|M J|MJ|', 'Bettadaiah|B K|BK|', 'Muthukumar|S P|SP|', 'Govindaraju|K|K|']
D000818:Animals D000893:Anti-Inflammatory Agents D001578:Benzopyrans D020134:Catalytic Domain D004305:Dose-Response Relationship, Drug D004423:Ear D004487:Edema D016166:Free Radical Scavengers D007249:Inflammation D008084:Lipoxygenase D016859:Lipoxygenase Inhibitors D008297:Male D033641:Millettia D062105:Molecular Docking Simulation D011485:Protein Binding D017208:Rats, Wistar D012639:Seeds
Anti-inflammatory property Karanjin Karanja ketone Oxime Oxazole Lipoxygenase