7-Oxodihydrokarounidiol [7-oxo-D:C-friedo-olean-8-ene-3 alpha,29-diol], a novel triterpene from Trichosanthes kirilowii.

The structure of 7-oxodihydrokarounidiol [7-oxo-D:C-friedo-olean-8-ene-3 alpha,29-diol], isolates from the seeds of Trichosanthes kirilowii (Cucurbitaceae), was determined by chemical correlation with karounidiol [D:C-friedo-oleana-7,9(11)-diene-3 alpha,29-diol] from the same source. Two other natural products, viz. bryonolic acid (3 beta-hydroxy-D:C-friedo-olean-8-en-29-oic acid) and bryononic acid (3-oxo-D:C-friedo-olean-8-en-29-oic acid), were also correlated with karounidiol.