Combining online size exclusion chromatography and electrospray ionization mass spectrometry to characterize plant polysaccharides.
Characterizing polysaccharides with large molecular weights and isomeric heterogeneity with mass spectrometry (MS) is generally difficult. In this work, we demonstrate how coupling size exclusion chromatography (SEC) and high-resolution MS with source-induced dissociation (SID) can be used for the separation and direct structural evaluation of intact polysaccharides. The analytical method was successfully developed using dextran standards up to 3755 kDa. This method was used to separate naturally occurring plant polysaccharides based on size, after which numerous polysaccharide fragments were identified from the resulting MS spectra. The results provided strong evidence for structural diversity, complexity, and heterogeneity among polysaccharides. MS showed superior sensitivity and reliability for the polysaccharides in eluted fractions when compared to a refractive index detector. Putative compositions for the fragments were proposed based on exact mass values. The work demonstrated that SEC-SID-MS is a feasible alternative for obtaining valuable structural information from the analysis of intact polysaccharides.
['Jiang|Qing|Q|', 'Wang|Ying|Y|', 'Li|Hongli|H|', 'Chen|David D Y|DDY|']
D027885:Astragalus propinquus D002850:Chromatography, Gel D029745:Codonopsis D031667:Dendrobium D006801:Humans D008970:Molecular Weight D010936:Plant Extracts D011134:Polysaccharides D011208:Powders D021241:Spectrometry, Mass, Electrospray Ionization D000070660:Wolfiporia
Size exclusion chromatography Mass spectrometry Plant polysaccharides Source-induced dissociation