摘要
α-Glucosidase and lipase inhibitors play important roles in the treatment of hyperglycaemia and dyslipidemia. To identify novel naturally occurring inhibitors, a bioactivity-guided phytochemical research was performed on the pu-erh tea. One new flavanol, named(–)-epicatechin-3-O-(Z)-coumarate(1), and 16 known analogs(2–17) were isolated from the aqueous extract of the pu-erh tea. Their structures were determined by spectroscopic and chemical methods. Furthermore, the water extract of pu-erh tea and its fractions exhibited inhibitory activities against α-glucosidases and lipases in vitro;compound 15 showed moderate inhibitory effect against sucrase with an IC_(50) value of 32.5 μmol/L and significant inhibitory effect against maltase with an IC_(50) value of 1.3 μmol/L. Compounds 8, 10, 11 and15 displayed moderate activity against a lipase with IC_(50) values of 16.0, 13.6, 19.8, and 13.3 μmol/L,respectively.
α-Glucosidase and lipase inhibitors play important roles in the treatment of hyperglycaemia and dyslipidemia. To identify novel naturally occurring inhibitors, a bioactivity-guided phytochemical research was performed on the pu-erh tea. One new flavanol, named(–)-epicatechin-3-O-(Z)-coumarate(1), and 16 known analogs(2–17) were isolated from the aqueous extract of the pu-erh tea. Their structures were determined by spectroscopic and chemical methods. Furthermore, the water extract of pu-erh tea and its fractions exhibited inhibitory activities against α-glucosidases and lipases in vitro;compound 15 showed moderate inhibitory effect against sucrase with an IC_(50) value of 32.5 μmol/L and significant inhibitory effect against maltase with an IC_(50) value of 1.3 μmol/L. Compounds 8, 10, 11 and15 displayed moderate activity against a lipase with IC_(50) values of 16.0, 13.6, 19.8, and 13.3 μmol/L,respectively.
基金
supported by grants from National Mega–Project for Innovative Drugs(2012ZX09301002-002)
