Five D:C-friedo-oleanane triterpenes from the seeds of Trichosanthes kirilowii Maxim. and their anti-inflammatory effects.

Five triterpenes with a D:C-friedo-oleanane skeleton, D:C-friedo-oleana-7,9(11)-diene-3 beta,29-diol (3-epikarounidiol), 7-oxo-D:C-friedo-olean-8-en-3 beta-ol (7-oxoisomultiflorenol), 7-oxo-8 beta-D:C-friedo-olean-9(11)-ene-3 alpha,29-diol, D:C-friedo-olean-8-ene-3 alpha,29-diol (3-epibryonolol), and D:C-friedo-olean-8-ene-3 beta,29-diol (bryonolol), the first four of which are new naturally occurring compounds, were isolated from the seeds of Trichosanthes kirilowii Maxim. The structures were determined by spectral and chemical methods. 3-Epikarounidiol, 7-oxoisomultiflorenol, and 3-epibryonolol showed marked inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear inflammation in mice. The 50% inhibitory dose of these triterpenes for TPA-induced inflammation (1 microgram) was 0.2-0.6 mg/ear.