New tricyclic alkaloids, cassiarins G, H, J, and K from leaves of Cassia siamea

Abstract

Four new alkaloids, cassiarins G, H, J, and K (1-4) which showed moderate antiplasmodial activity against Plasmodium falciparum 3D7, were isolated from the leaves of Cassia siamea (Leguminosae) and the structures of 1-4 were elucidated by 1D- and 2D-NMR analysis and X-ray crystallographic analysis. © 2012 The Pharmaceutical Society of Japan.