New cucurbitane triterpenoids and steroidal glycoside from Momordica charantia

Three new cucurbitane triterpenoids 1-3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5 beta,19-epoxycucurbita-6,23-diene-3beta,25-diol 3-O-beta-glucopyranoside (1), 23-O-beta-allopyranosylecucurbita-5,24-dien-7 alpha,3beta,22(R),23(S)-tetraol 3-O-beta-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[beta-glucopyranosyl(1-->6)]-O-beta-glucopyranosyl}-25-O-beta-glucopyranoside (3), and 24(R)-stigmastan-3beta,5 alpha,6 beta-triol-25-ene 3-O-beta-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.