5alpha-reductase inhibitory effect of triterpenoids isolated from Ganoderma lucidum

5alpha-Reductase inhibitory activity-guided fractionation of the EtOH extract of the fruiting body of Ganoderma lucidum (LEYSS.:FR.) KARST. (Ganodermataceae), which is called Reishi, or Mannentake in Japan and Lingzhi in China, led to the isolation of two active compounds which were ganoderic acid DM and 5alpha-lanosta-7,9(11),24-triene-15alpha,26-dihydroxy-3-one with an IC(50) of 10.6 microM and 41.9 microM respectively. A carboxyl group of side chain of ganoderic acid DM is essential to elicit the inhibitory activity because of much less activity of its methyl ester.