CHEMICAL AND PHARMACOLOGICAL CHARACTERIZATION OF ERYTHROPHLEUM-LASIANTHUM ALKALOIDS

Two alkaloids 1 and 2 were isolated from the seeds of Erythrophleum la sianthum. Their structures were assigned by spectroscopic and chemical means as 3 beta-hydroxynorerythrosuamine (1) and its 3-O-beta-D-gluco pyranoside (2). In spontaneously beating atria, both compounds 1 and 2 showed a marked and concentration-dependent positive inotropic activi ty and a weak negative chronotropic activity. The positive inotropic e ffect induced by 1 and 2 was not modified by propranolol, prazosin, ca rbachol, and ranitidine plus pyrilamine. Both 1 and 2 were very active in inhibiting the Na+/K+-ATPase isolated from bovine cardiac sarcolem mal vesicles.