Studies on the Constituents of the Seeds of Cassia obtusifolia LINNE. IV. : The Structure of New Glucoside, Cassiaside (Norrubrofusarin-6-β-D-glucoside)

Abstract

The preceding papers reported the isolation of anthraquinone derivatives, chrysophanol, physcion, obtusifolin, chryso-obtusin, aurantio-obtusin, gluco-obtusifolin, and gluco-aurantioobtusin from the seeds of Cassia obtusifolia LINNE (Leguminosae). Subsequently, a new glucoside, cassiaside, pale yellow micro needles, m.p. 256∼257°, C₂₀H₂₀O₁₀, was isolated from the methanol extracts of these seeds by column chromatography. It gave 1 mole of nor-rubrofusarin (II) and 1 mole of glucose, and its permethyl ether afforded 5, 8-di-O-methyl-nor-rubrofusarin (IV) by hydrolysis with 5% hydrochloric acid. Thus, the structure of cassiaside has been established as nor-rubrofusarin-6-β-mono-D-glucoside.