Sesquiterpene Aminoquinones, from a Marine Sponge, Induce Erythroid Differentiation in Human Chronic Myelogenous Leukemia, K562 Cells

A new sesquiterpene aminoquinone, 5-epi-smenospongorine, together with nine known sesquiterpene quinone/phenols, was isolated as differentiation-inducing substances to K562 cells into erythroblast from the marine sponge Dactylospongia elegans. The structure–activity relationship study of these compounds clarified that the quinone skeleton is indispensable and the amino group plays an important role for their differentiation-inducing activity to K562 cells into erythroblast.