Cortistatins J, K, L, novel abeo-9(10-19)-androstane-type steroidal alkaloids with isoquinoline unit, from marine sponge Corticium simplex

Abstract Three novel anti-angiogenic steroidal alkaloids, cortistatins J ( 1 ), K ( 2 ), L ( 3 ), have been isolated from the Indonesian marine sponge Corticium simplex . The chemical structures of cortistatins J ( 1 ), K ( 2 ), and L ( 3 ) were determined by 2D-NMR analysis to be unique abeo-9(10-19)-androstane-type steroidal alkaloids having isoquinoline unit instead of the side chain part, respectively. Cortistatin J ( 1 ) showed cytostatic anti-proliferative activity against human umbilical vein endothelial cells (HUVECs) at 8 nM, in which the selective index was 300–1000-fold in comparison with other cell lines.