• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1324-1327
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• 2005

A methylene chloride soluble fraction of the fruits of Cudrania tricuspidata significantly inhibited the mouse brain monoamine oxidase (MAO). Three known prenylated isoflavones were isolated and identified by activity-guided fractionation. Gancaonin A (1), 4'-O-methylalpinumisoflavone (2), and alpinumisoflavone (3) inhibited MAO activity in a concentration-dependent manner with $IC_{50}$ values of 19.4, 23.9, and 25.8 $\mu$M, respectively. Of these, gancaonin A (1) showed a selective and potent inhibitory effect against MAO-B ($IC_{50}$ 0.8 $\mu$M) than MAO-A ($IC_{50}$ >800 $\mu$M). The kinetic analysis using Lineweaver-Burk plots indicated that gancaonin A (1) competitively inhibited MAO-B.