Absolute Stereostructures of Trifoliones A, B, C, and D, New Biologically Active Diterpenes from the Tuber of Sagittaria trifolia L.

Abstract

Four new biologically active diterpenes, trifoliones A, B, C, and D, were isolated from the tuber of Sagittaria trifolia L. together with three new glycosides, sagittariosides a and b and arabinothalictoside. Their stereostructures were determined on the basis of chemical and physicochemical evidence which included the application of a modified Mosher's method and an exciton chirality method. Trifoliones A, B, C, and D exhibited inhibitory effects on the histamine release from rat mast cells induced by compound 48/80 or calcium ionophore A-23187.