[Alpha-glucosidase inhibitors from leaves of Forsythia suspense in Henan province].
OBJECTIVE
The alpha-glucosidase inhibitory compounds were searched from Forsythia suspense.


METHODS
The active compounds were isolated by the method of bioassay-guided in vitro and column chromatographic techniques. The structures of compounds were identified by MS and NMR spectroscopy. The inhibitory kinetics of the isolated compounds were investigated.


RESULTS
The ethyl acetate extract showed the strongest inhibitory activity, and five active compounds were isolated from this extract. The IC50 value of compound 1-5 were all lower than that of acarbose as positive control. Compound 1, the mixture of 1, 2 and 4 all showed noncompetitive type model on alpha-glucosidase.


CONCLUSIONS
Compound 1-3 as the inhibitors of alpha-glucosidase were reported for the first time. Compound 3 was isolated from the genus for the first time.
Kang
Wenyi
W
Institute of Chinese Materia Medica, Henan University, Kaifeng 475004, China. kangweny@hotmail.com
Wang
Jinmei
J
Zhang
Li
L
D002681:China; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D031657:Forsythia / Q000737:chemistry*; D065089:Glycoside Hydrolase Inhibitors; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry; D000520:alpha-Glucosidases / Q000737:chemistry
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D000520:alpha-Glucosidases