Flavanols from thevar.and their hypoglycemic and hypolipidemic activities

ABSTRACT

-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---coumarate (), andknown analogs (-) 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-glucosidases and lipases; compoundshowed moderate inhibitory effect against sucrase with an ICvalue of 32.5 μmol/L and significant inhibitory effect against maltase with an ICvalue of 1.3 μmol/L. Compounds,,anddisplayed moderate activity against a lipase with ICvalues of 16.0, 13.6, 19.8, and 13.3 μmol/L, respectively.