Two new bitetrahydroanthracenes from Roots of Cassia occidentalis L.

Abstract

Two new bitetrahydroanthracene derivatives, occidentalol-I (2) and occidentalol-II (3), were isolated from the roots of Cassia occidentalis L. along with chrysophanol, emodin, pinselin, questing, germichrysone, methylgermitorosone and singueanol-I (1). The structures of 2 and 3 were estabilished as 3, 3', 4, 4'-tetrahydro-3, 3', 8, 8'9, 9'-hexahydroxy-6, 6'-dimethoxy-3, 3', 7-trimethyl-1(2H), 1'(2H)-10, 10'-bianthracenone and 3, 3', 4, 4'-tetrahydro-3, 3', 8, 8', 9, 9'-hexahydroxy-6, 6'-dimethoxy-3, 3'-dimethyl-1(2H)-, 1'(2H)-10, 10'-bianthracenone, respectively, on the basis of spectral evidence.