Trigochinins A-C: three new daphnane-type diterpenes from Trigonostemon chinensis.

Three highly oxygenated new diterpenes, trigochinins A-C (1-3) were isolated from Trigonostemon chinensis. Their structures with the absolute configuration were determined by a spectroscopic method, X-ray crystallography, and CD analysis. This study suggested the revision of the C-6 stereochemistry of trigonothyrins A-C reported quite recently. Compound 3 showed significant inhibition against MET tyrosine kinase activity with a IC(50) value of 1.95 microM.