New vasorelaxant indole alkaloids, villocarines A-D from Uncaria villosa

  • Bioorg Med Chem. 2011 Jul 1;19(13):4075-9. doi: 10.1016/j.bmc.2011.05.014.
Hirotaka Matsuo  1 ,  Ryuichi Okamoto ,  Kazumasa Zaima ,  Yusuke Hirasawa ,  Intan Safinar Ismail ,  Nordin Hj Lajis ,  Hiroshi Morita
Affiliations
  • 1. Faculty of Pharmaceutical Sciences, Hoshi University, Shinagawa-ku, Tokyo, Japan.
PMID: 21641808 DOI: 10.1016/j.bmc.2011.05.014
Abstract

Villocarines A-D (1-4), four new Indole Alkaloids have been isolated from the leaves of Uncaria villosa (Rubiaceae) and their structures were elucidated by 2D NMR methods and chemical correlations. Villocarine A (1) showed vasorelaxation activity against rat aortic ring and showed inhibition effect on vasocontraction of depolarized aorta with high concentration potassium, and also inhibition effect on phenylephrine (PE)-induced contraction in the presence of nicardipine in a CA(2+) concentration-dependent manner. The vasorelaxant effect by 1 might be attributed mainly to inhibition of calcium influx from extracellular space through voltage-dependent calcium channels (VDC) and/or receptor-operated CA(2+)-channels (ROC), and also partly mediated through the increased release of NO from endothelial cells and opening of voltage-gated K(+)-channels.

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