Chemical Studies on Crude Drug Processing IX. On the Constituents of Rehmanniae Radix. (3). Absolute Stereostructures of Rehmaionosides A, B, and C, and Rehmapicroside, Biologically Active Ionone Glucosides and a Monoterpene Glucoside Isolated from Chinese Rehmanniae Radix

Following the characterization of the iridoid and iridoid glycoside constituents in Chinese Rehmanniae Radix, the dried root of Rehmannia glutinosa LIBOSCH. [Kan-jio in Japanese], we investigated the structures of biologically active ionone glucosides, rehmaionosides A, B, and C, and a monoterpene glucoside, rehmapicroside. Their absolute stereostructures were determined on the basis of chemical and physicochemical evidence, which included the result of application of the exciton chirality method to the allylic benzoyl derivatives.