In order to estimate the effects of the A-ring hydroxyl group of baicalein (5, 6, 7- trihydroxyflavone, 1) on rat intestinal α-glucosidase inhibition, flavone, monohydroxyflavones, dihydroxyflavones, and methylated derivatives of 5, 6, 7- trihydroxyflavone were used for the structure-activity relationship (SAR) study. The importance of the 6-hydroxyl group of baicalein was validated for an exertion of the activity ...