Cucurbitane-type triterpenoids from the stems and leaves of Momordica charantia.

ABSTRACT

Six new cucurbitane-type triterpenoids, karavilagenin F (1), karavilosides XII and XIII (2, 3), momordicines VI, VII, and VIII (4, 5 and 6), along with four known ones, 5ß,19-epoxy-25-methoxycucurbita-6,23-diene-3ß,19-diol (7), 5ß,19-epoxycucurbita-6, 23-diene-3ß,19,25-triol (8), kuguacin R (9), and (19R,23E)-5ß,19-epoxy-19-methoxycucurbita-6,23,25-trien-3ß-ol (10), were isolated from the stems and leaves of Momordica charantia L. Their chemical structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, COSY, and ROESY), MS experiments, and CD spectrum. Compound 6 showed weak cytotoxicity against five human cancer cells lines with IC50 values of 14.3-20.5µmol/L.