A new dammarane type triterpene glucoside from the aerial parts of Gouania longipetala (Rhamnaceae).

3-O-ß-D-glucopyranosyl gouanogenin A (1), a new naturally occurring dammarane class of triterpene glucoside, has been isolated from the aerial parts of Gouania longipetala along with six known secondary metabolites 2-7. Their structure was elucidated through spectroscopic data including 1 D- and 2 D-NMR. The compounds 1 and 6 showed significant antioxidant potential in DPPH radical scavenging assay. On the other hand, the compound 4 revealed potent inhibitory potential against the enzyme urease, while 1 and 3 were significantly active.

Antiproliferative and cytotoxic secondary metabolites from fruits of Leplaea mayombensis.

Two new seco-lanostane-type triterpenes, named mayomlactones A (1) and B (2) were isolated from the fruits of Leplaea mayombensis together with 10 known compounds (3-12). Structures of the new compounds were elucidated by extensive spectroscopic studies. Except compounds 11 and 12, all the other chemical compounds are newly reported from Leplaea genus. From the results of this investigation, compounds 1-10 were examined for antiproliferative activity against HeLa cells as well as cytotoxicity against 3T3 cell line. Compounds 3 and 4 showed moderate antiproliferative activity with IC50 values of 10.4 ± 0.1 and 18.6 ± 0.2 µM, respectively. On the other hand, compounds 1, 4 and 9 showed weak cytotoxicity with IC50 values 44.1 ± 0.5, 55.8 ± 0.7 and 55.1 ± 0.5 µM. Overall, none of the tested compounds showed good selectivity (SI ranging from 0.51 to 3.06) but high toxicity against the 3T3 cell line.