[Chemical constituents of Cassia occidentalis]

Compounds(1-6) were isolated and identified from 90% ethanol extract of the stems and leaves of Cassia occidentalis through column chromatography with silica gel, ODS, and Sephadex LH-20. These compounds were identified as 7-hydroxy-5-(3-hydroxy-2-oxopropyl)-2-methyl-4H-chromen-4-one(1), saccharonol A(2), S-6-hydroxymullein(3), 2-methyl-5-acetonyl-7-hydroxy-chromone(4), 2-(2'-hydroxypropyl)-5-methyl-7-hydroxychromone(5) and 7,4'-dihydroxyflavone(6) based on their physicochemical and spectroscopic data. Among them, compound 1 was a new compound, and all the compounds were isolated from this plant for the first time. DPPH method was employed to determine the antioxidant activities of these compounds in vitro. Six compounds exhibited weak antioxidant activities.