Abstract

Zanthoxylum pistaciifolium Griseb. is a tree endemic to Cuba, occasionally used in herbal medicine. Previously, the antitrypanosomal activity of a n-hexane-2-butanone extract of Z. pistaciifolium leaves and of its constituent skimmianine were published. In the current study a more thorough examination of the respective extract is performed, which led to the isolation and identification of three flavonoids, more specifically, the flavonol-3-O-methylethers kaempferol-3-O-methylether (1) and novel compounds kaempferol-3-O-methylether-5-O-beta-D-glucoside (2) and kaempferol-8-hydroxy-3,7-O-dimethylether-5-O-beta-D-glucoside (3). All compounds were screened for their antimicrobial and antiprotozoal activity and cytotoxicity towards MRC-5 SV2 cells. Compound 1 showed a moderate to weak activity against Trypanosoma cruzi (IC50 30.8 mu M), T. brucei (IC50 15.4 mu M) and Plasmodium falciparum (IC50 53.8 mu M), but also showed cytotoxicity (CC50 19.0 mu M). Compounds 2 and 3 did not display activity in any of the assays (IC50 and CC50 > 64 mu M).