Salaterpene E, a eudesmane-type sesquiterpene from Salacia longipes var. camerunensis

A mixture of two compounds with potent antiplasmodial activity in vitro against the W2 strain of Plasmodium falciparum (half maximal inhibitory concentration, 1.12 μg/mL) was obtained in a previous investigation of the CH2Cl2-MeOH extract of the seeds of Salacia longipes var. camerunensis. Separation by column chromatography led now to the isolation of salaterpene E (1) and (1R,2R,4S,5S,6R,7R,9S,10R)-2-acetoxy-1,6,9-tribenzoyloxy-4-hydroxy-dihydro-β-agarofuran (2). The structure of 1 was elucidated by spectroscopic analysis, and its absolute configuration was established unambiguously by means of single-crystal X-ray diffraction. Also the absolute configurations of the recently described salaterpenes A (2a) and D (2b) were determined by this method using the anomalous scattering of the oxygen atoms only.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, onoceranes and saponins; 308 references are cited.