Cycloartane triterpenes isolated from Combretum quadrangulare in a screening program for death-receptor expression enhancing activity

  • J Nat Prod. 2011 Feb 25;74(2):249-55. doi: 10.1021/np100784t.
Kazufumi Toume  1 ,  Takafumi Nakazawa ,  Takashi Ohtsuki ,  Midori A Arai ,  Takashi Koyano ,  Thaworn Kowithayakorn ,  Masami Ishibashi
Affiliations
  • 1. Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
PMID: 21265555 DOI: 10.1021/np100784t
Abstract

In our screening program for natural products that increase DR5 (death-receptor 5) expression, nine new cycloartane Triterpenes, combretanones A-G (1-7), combretic acid A (8), and combretic acid B (9), were isolated from a MeOH extract of Combretum quadrangulare leaves. The known oleanane Triterpenes (10, 11) and six known Flavonols (12-17) were also isolated. The structures of 1-9 were elucidated by spectroscopic studies. Compounds 7, 9, 12, 16, and 17 enhanced DR5 expression, and 16 showed TRAIL-resistance abrogating activity.

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