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Three new triterpenoids (I)-(III) are isolated from the tendril climber Momordica charantia.

Compounds (I), (III) and (IV) exhibit promising cytotoxic activity against human hepatoma SK Hep-1 cells.

Four novel octanorcucurbitane triterpenes, octanorcucurbitacins A—D (1—4), together with one known octanorcucurbitane triterpene, kuguacin M (5), were isolated from the methyl alcohol extract of the stems of Momordica charantia. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compound 3 inhibited tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity against HepG2 cells.

Four new D:C-friedooleanane-type triterpenes, 3β-O-(E)-feruloyl-D:C-friedooleana-7,9(11)-dien-29-ol (1), 3β-O-(E)-coumaroyl-D:C-friedooleana-7,9(11)-dien-29-ol (2), 3β-O-(E)-coumaroyl-D:C-friedooleana-7,9(11)-dien-29-oic acid (3), and methyl 2β,3β-dihydroxy-D:C-friedoolean-8-en-29-oate (6), together with five known triterpenes with the same skeleton, 3-epikarounidiol (4), 3-oxo-D:C-friedoolena-7,9(11)-dien-29-oic acid (5), bryonolol (7), bryononic acid (8), and 20-epibryonolic acid (9), were isolated from the methanol extract of the stems of Lagenaria siceraria. The structures of those compounds were elucidated using spectroscopic methods. Compounds 3 and 9 showed significant cytotoxic activity against the SK-Hep 1 cell line with IC50 values of 4.8 and 2.1 μg/ml, respectively. Based on these initially promising results, the two D:C-friedooleanane triterpenes merit further study as potential anticancer agents.

Four new lanostane-type triterpenes, 24-ethyl-3beta-methoxylanost-9(11)-en-25-ol (1), 3beta-methoxy-24-methylenelanost-9(11)-en-25-ol (2), 3beta-methoxy-25-methyl-24-methylenelanost-9(11)-en-21-ol (3) and 3beta-methoxy-24-methyllanosta-9(11),25-dien-24-ol (4) together with three known triterpenes, betulinaldehyde, betulinic acid methyl ester, and ursaldehyde have been isolated from the methanol extract of the twigs of Diospyros discolor. The structures of those new compounds were elucidated by spectroscopic methods.