Alkamides from the leaves of Zanthoxylum syncarpum.

Three alkamides (1-3) were isolated from the leaves of Zanthoxylum syncarpum. The structures of the new compounds 1 and 2 were established by spectroscopic data and chemical conversion, and by the X-ray crystallography of 1. Compound 3, the racemic form of the known compound syncarpamide, showed moderate antiplasmodial activity, with IC50 values of 4.2 and 6.1 microM against Plasmodium falciparum D6 clone and W2 clone, respectively.