Rhamnogalacturonan I-Enriched Pectin, Flavonoids, and Alkaloids from Lotus Leaf Infusion in Regulating Glycolipid Absorption and Metabolism: Isolation, In Vitro Bioactivity Verification, and Structural Characterization

作者：Ke, Yu; Lin, Lianzhu^*; Zhao, Mouming

来源：Journal of Agricultural and Food Chemistry, 2023, 71(23): 8969-8980.

DOI：10.1021/acs.jafc.3c02522

• lotus leaf
• glycolipid absorption and metabolism
• rhamnogalacturonan I-enriched pectin
• alkaloids
• flavonoids
• structural characterization

Lotus leaf is effective in regulating glycolipid absorptionandmetabolism, but the roles of small-molecule compounds and polysaccharidesare unknown. In this study, the small-molecule compounds includingflavonoids, alkaloids, and polysaccharides were gradually isolatedfrom lotus leaf infusion by multi-column chromatography and appliedto in vitro activity verification and structural characterization.Although flavonoids and alkaloids were effective in inhibiting pancrelipaseand alpha-glucosidase, polysaccharides more effectively boundedbile acids, inhibited cholesterol micelle solubility, and stimulatedthe growth of Bifidobacterium than lotus leaf infusion.Polysaccharides, presented as spherical conformation in water, wereidentified as rhamnogalacturonan I-enriched (93%) low-ester pectinwith multiple branches mainly composed of arabinan, arabinogalactan-typeII, and galactan formed by -> 3)-Galp-(1 ->,-> 5)-Araf-(1 -> and -> 4)-Galp-(1 -> residues. Polysaccharides, which were a keyconstituent of lotus leaf infusion in regulating glycolipid absorptionand metabolism, should be paid more attention and developed as a functionalfood ingredient.