α-Glucosidase inhibitory oligosaccharides derived from thinned peach fruit: preparation, identification, and effects on IR-HepG2 cells

In this study, we focused on the key hypoglycemic oligosaccharide components derived from thinned peach crude polysaccharides (CPPS), elucidated their structural characteristics and hypoglycemic mechanisms, and improved the utilization of this agricultural waste. CPPS was fractionated via anion-exchange chromatography and ultrafiltration, yielding 2 key components (W1-2 and W2-2) with enhanced α -glucosidase inhibition and half maximal inhibitory concentration (IC 50 ) were 0.57 and 0.37 mg/mL, respectively. They improved glucose consumption, glycogen synthesis, hexokinase, and pyruvate kinase activities in insulin resistant HepG2 cells. Structural analysis using LC-MS and methylation revealed W1-2 contains disaccharides where galactose or glucose is linked to terminal arabinose through 1,4-glycosidic bonds, alongside arabinose-rich pentasaccharides featuring T-Ara f , 1,5-Ara f and 1,3,5-Ara f residues. W2-2 comprises trehalose-like disaccharides with accounting for 76.95% of T-Glc p and arabinose pentasaccharides with similar branching patterns. These findings suggest that trehalose-like disaccharides and arabinose-derived pentasaccharides in CPPS may play a key role in blood glucose regulation. This study offers important insights into the roles of bioactive carbohydrates in diabetes intervention.