Structures of new sesquiterpenes and hepatoprotective constituents from the Egyptian herbal medicine Cyperus longus.

Six new sesquiterpenes, cyperusols A(1) (1), A(2) (2), B(1) (3), B(2) (4), C (5), and D (6), together with two monoterpenes and 13 sesquiterpenes were isolated from an Egyptian herbal medicine, the whole plants of Cyperus longus. The stereostructures of the new sesquiterpenes were determined on the basis of chemical and physicochemical evidence. In addition, the principal constituents were found to exhibit inhibitory activity on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes.