Journal of Wood Science

, Volume 49, Issue 4, pp 339–343

5Α-Reductase inhibitory tannin-related compounds isolated from Shorea laeviforia

Authors

  • Yoshio Hirano
    • Interior Design Research InstituteFukuoka Industrial Technology Center
  • Ryuichiro Kondo
    • Department of Forest and Forest Products Sciences, Faculty of AgricultureKyushu University
  • Kokki Sakai
    • Department of Forest and Forest Products Sciences, Faculty of AgricultureKyushu University
ORIGINAL ARTICLE

DOI: 10.1007/s10086-002-0481-y

Cite this article as:
Hirano, Y., Kondo, R. & Sakai, K. J Wood Sci (2003) 49: 339. doi:10.1007/s10086-002-0481-y

Abstract

Five tannin-related compounds – gallic acid, flavogallonic acid dilactone, valoneic acid dilactone, gallagyldilactone, ellagic acid – were isolated from the heartwood of Shorea laeviforia, and the inhibitory activity of each against rat liver 5Α-reductase was evaluated. Valoneic acid dilactone and gallagyldilactone exhibited positive inhibitory activity, but gallic acid and ellagic acid did not. Flavogallonic acid dilactone stimulated 5Α-reductase activity, even though this compound is structurally similar to valoneic acid dilactone. The kinetic study of valoneic acid dilactone and gallagyldilactone indicated that the inhibitory behavior of 5Α-reductase were not competitive against the substrate (testosterone) and were partially competitive against the cofactor (NADPH). Additionally, double inhibition analysis of valoneic acid dilactone and NADP+ showed synergetic inhibition. These results suggested that neither valoneic acid dilactone nor gallagyldilactone can affect the binding of testosterone but that either compound could interact with an enzyme–NADP+ complex to inhibit 5Α-reductase.

Key words

Shorea laeviforiaTannin-related compoundsValoneic acid dilactoneGallagyldilactone5Α-Reductase inhibitor

Copyright information

© Springer-Verlag Tokyo 2003