[Alpha-glucosidase inhibitors from Rubia cordifolia].
OBJECTIVE
To search alpha-glucosidase inhibitors from Rubia cordifolia.


METHODS
The alpha-glucosidase inhibitors were isolated by the column chromatographic techniques and the bioassay-guided method in vitro. A combination of MS and NMR spectroscopy was used to identify the chemical structures. The inhibitory kinetics of the inhibitors were also investigated.


RESULTS
The chloroform extract showed high inhibitory activity, and three active compounds were isolated and identified as 1,3-dihydroxy-2-methylanthraquinone (1), 1-hydroxy-2-methylanthraquinone (2) and 1,2-dihydroxyanthraquinone (3). The IC5o values of compound 1-3 were all lower than that of acarbose. Compound 1 and 2 shown competitive type manner on alpha-glucosidase, whereas compound 3 shown noncompetitive type model.


CONCLUSIONS
Compounds 1-3 as strong inhibitors of alpha-glucosidase were reported for the first time.
Kang
Wenyi
W
Institute of Natural Products, Pharmaceutical College, Henan University, Kaifeng 475004, China. kangweny@hotmail.com
Zhang
Li
L
Song
Yanli
Y
D001667:Binding, Competitive; D004791:Enzyme Inhibitors / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D020128:Inhibitory Concentration 50; D007700:Kinetics; D045470:Rubia / Q000737:chemistry*; D000520:alpha-Glucosidases / Q000378:metabolism
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D000520:alpha-Glucosidases