Alpha-glucosidase inhibitors from Rubia cordifolia / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>To search alpha-glucosidase inhibitors from Rubia cordifolia.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>Compounds 1-3 as strong inhibitors of alpha-glucosidase were reported for the first time.</p>