Xanthone glycosides from Swertia bimaculata with α-glucosidase inhibitory activity.

Seven new xanthone glycosides (1-7) were isolated from the n-butanol extract of Swertia bimaculata, together with six known compounds (8-13). Their structures were elucidated on the basis of extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, and IR) and comparison with data reported in the literature. All the compounds were evaluated for their α-glucosidase inhibitory activities in vitro, and compounds 3, 4, and 7 exhibited significant activities to inhibit α-glucosidase.

Antidiabetic effects of Swertia macrosperma extracts in diabetic rats.

Ethnopharmacological Relevance: Swertia macrosperma is a traditional folk medicine used for its anti-hepatitis, antipyretic and antidotal effects as "Dida" or "Zangyinchen" in Tibet, Yunnan and Guizhou province for a long time, and it has been reported for its anti-diabetic effects in a Chinese patent. Swertia macrosperma was reported rich in xanthones, iridoids, seco-iridoids and their glycosides, several of which had been documented as potential antidiabetic agents. The objective of this study was to investigate the antidiabetic effect of Swertia macrosperma in diabetic rats.

Preventive effects of polysaccharides from Liriope spicata var. prolifera on diabetic nephropathy in rats.

This study was undertaken to investigate preventive effects of polysaccharides (LSP) from Liriope spicata var. prolifera on diabetic nephropathy in rats, which were induced by high fat-fed and low-dose streptozotocin (STZ). The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in diabetic rats were significantly decreased after treated with LSP for 28 days.

Xanthone glycoside constituents of Swertia kouitchensis with α-glucosidase inhibitory activity.

Ten new xanthone glycosides, kouitchensides A-J (1-10), and 11 known analogues were isolated from an n-butanol fraction of Swertia kouitchensis. The structures of these glycosides were determined on the basis of extensive spectroscopic data interpretation and comparison with data reported in the literature. In an in vitro test, compounds 2, 4, 5, 6, 11, 12, and 13 (IC50 values in the range 126 to 451 μM) displayed more potent inhibitory effects against α-glucosidase activity than the positive control, acarbose (IC50 value of 627 μM).