Structure-activity Relationships for α-Glucosidase Inhibition of Baicalein, 5,6,7-Trihydroxyflavone: the Effect of A-Ring Substitution

• DOI: 10.1271/bbb.68.369
• Publication Date: 2004-02-24T06:02:06Z
• Authors: Hong GAO; Tetsuo NISHIOKA; Jun Kawabata; Takanori KASAI
• Keywords: Baicalein; Polar effect; Structure–activity relationship; Flavones

In order to estimate the effects of A-ring hydroxyl group baicalein (5,6,7-trihydroxyflavone, 1) on rat intestinal alpha-glucosidase inhibition, flavone, monohydroxyflavones, dihydroxyflavones, and methylated derivatives 5,6,7-trihydroxyflavone were used for structure-activity relationship (SAR) study. The importance 6-hydroxyl was validated an exertion activity. And also, tested flavones which lacked a substituent any positions 5, 6, or 7, showed no Hence, structure concluded be crucial potent inhibitory addition, introduction electron-withdrawing electron-donating groups at position 8 led dramatic decrease activity, except 8-fluoro-5,6,7-trihydroxyflavone, carried less bulky 8. this result suggested that sterically C-8 detrimental activity regardless its electronic nature. Through examining mechanism against alpha-glucosidase, it mixed type inhibition.