Compounds inhibitory to rat liver 5α-reductase from tropical commercial wood species: Resveratrol trimers from melapi (Shorea sp.) heartwood

Abstract

5α-Reductase inhibitory activity of methanol extracts of the heartwood of 13 tropical wood species were examined. Strong 5α-reductase inhibitory activity was observed with Shorea species. From melapi (Shorea sp.), two known resveratrol trimers, vaticanol A and ampelopsin C, and two novel trimers were isolated as active compounds. The structures of the two novel resveratrol trimers were elucidated by one- and two-dimensional nuclear magnetic resonance spectroscopic analyses, including 1H-1HCOSY, HMQC, and HMBC. The compounds were named melapinol A and melapinol B. There were no significant differences among the 5α-reductase inhibitory activities of the four resveratrol trimers, which were significantly stronger than those of α-linolenic acid and epigallocatechin gallate, known 5α-reductase inhibitors. © The Japan Wood Research Society 2001.