Two new naphthalene glycosides from the seeds of Cassia obtusifolia

A phytochemical study on the seeds of Cassia obtusifolia was carried out, which finally led to obtain two naphthalenes (1 and 2), two naphthopyrans (3 and 4) and twelve anthraquinones (5–16). The structures of all compounds were established mainly by NMR and MS experiments as well as the necessary chemical evidence. Among them, 1 and 2 (obtusinaphthalensides A and B) were identified to be new naphthalene glycosides.