Production and identification of intricate bioactive oligosaccharides from Nyctanthesarbor-tristis leaves by a combination of enzymatic, HPAEC and MALDI-TOF-MS techniques

Abstract

Non-digestible oligosaccharides are associated with positive health outcomes; however, hemicellulosic oligosaccharides of N. arbor-tristis have not been studied. Herein, we report production of hemicellulosic oligosaccharides from its leaves and their identification. A series of complex neutral oligosaccharides (1-16), produced by endo-(1,4)--D-glucanase digestion of the alkali extracted xyloglucan, have been identified by chemical, HPAE chromatographic and MALDI-mass spectrometric techniques. Additionally, xylan enriched hemicellulose-A fraction upon endo-(1,4)--D-xylanase digestion yield several acidic and neutral xylo-oligosaccharides (17-24), each containing a backbone of -(1,4)-D-Xylp units substituted at position 2 with a single stub of D-Xylp or 4-O-Me-D-GlcpA residues. The structural diversity and high water solubility of these enzyme-generated oligosaccharides suggested promising health implications.