Cycloartane triterpenes isolated from Combretum quadrangulare in a screening program for death-receptor expression enhancing activity.
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.
Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
Kazufumi
K
Toume
Takafumi
T
Nakazawa
Takashi
T
Ohtsuki
Midori A
MA
Arai
Takashi
T
Koyano
Thaworn
T
Kowithayakorn
Masami
M
Ishibashi
D029765:Combretum / Q000737:chemistry*; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000819:agonists* / Q000187:drug effects / Q000235:genetics; D013785:Thailand; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D014315:Triterpenes; C085352:cycloartane