Novel Potent Hypoglycemic Compounds from Champ. and Their Effect on Reducing Plasma Glucose in an ICR Mouse Model.

α-Glucosidase inhibitors (aGIs) have been used as an effective therapy for type-2 diabetes, which remains a global health issue. The aim of this study was to achieve bioactivity-guided isolation, identification and evaluation of hypoglycemic compounds from Champ. trunk bark (ELCTB). Eleven active compounds were isolated and identified as walterolactone A/B β-d-pyranoglucoside (), 1-β-d-glucopyranosyloxy-3,5-dimethoxy-4-hydroxybenzene (), (-)-gallocatechin (), schweinfurthinol 9--β-d-pyranoglucoside (), 1--(3-methyl)-butenoyl-myo-inositol (), leonuriside (), (+)-catechin (), methyl galloate (), (-)-catechin (), and condensed tannins ( and ). Of these 11, novel 4 compounds (, , , and ) were found as new α-glucosidase inhibitors. Notably, in vitro results indicated that compounds , , ⁻, , and showed potent activity (IC = 0.076-31 µg/mL), and their activities were at a higher level than that of acarbose, a commercial inhibitor (IC = 1345 µg/mL). In animal tests, the major inhibitor, condensed tannin (), demonstrated significant reduction of plasma glucose in mice with no symptoms of diarrhea at the dose of 100 mg/kg bw. The results suggest that Champ. is a rich source of bioactive compounds for development as health food or drugs with potent hypoglycemic effect. The results of this study also enriched the current novel biological activities of constituents from species.