Dimeric alkaloids from the barks of Erythrina variegata as well as their occurrence

Thirteen undescribed dimeric Erythrina alkaloids, named as erythrivarines A1-A13, were isolated from the barks of Erythrina variegata L. and. Their structures were determined on the basis of NMR, UV and mass spectral an-alyses. Dimeric Erythrina alkaloid with a C-8/8' linkage in erythrivarine A1 was not yet reported. Representative dimers from titled plant were used to prove their occurrence as natural products by LC -MS detection. Addi-tionally, simultaneous investigation enabled us to propose the natural property of seemingly artificial Erythrina alkaloid with acetonyl group.