[Novel triterpenoids from Cynanchum hancockianum].

Four new triterpenoids have been isolated from the petroleum ether extract of Cyananchum hancockianum (Maxim) Al. Iljinski (Asclepiadaceae). On the basis of spectral data (1HNMR, 13CNMR, 1H-1H COSY, 1H-13C COSY, longrange 1H-13C COSY, MS, X-Ray analysis) and chemical connections, they were identified as hancockinol (Ia), hancolupenol (IIa), hancolupenone (IIc), and hancolupenol octacosanate (IId). They are of new skeletons with B/C cis, C/D trans, D/E cis junctures for Ia and with A/B trans, C/D trans, D/E cis junctures for IIa, IIc and IId.