Cassia alata is a medicinal herb of the Fabaceae family. It is a general shrub tree growing wild in Viet Nam. Preliminary investigation of chemical composition found that triterpenoid, anthraquinone, coumarin, cardiac glycoside, flavonoid, saponin, and polyuronide in leaves of Cassia alata. The leaves were collected and extracted by percolation with ethanol 96%. The total extract was then fractionated by liquid-liquid extraction with solvents of different polarities to obtain fractional extracts: hexane, chloroform, ethyl acetate, and water. The chloroform extract was converted to phenolate to obtain CF2 extract. CF2 was isolated by classical column chromatography and three compounds were obtained: aloe-emodin (20 mg), kaemferol (10 mg), and rhein (56 mg). They were tested and determined that they are pure on the thin layer chromatography. The structure of the compounds was determined by NMR and compared with published documents. These studies will be the basis for conducting bioactivity surveys and isolating compounds in hexane and ethyl acetate fractions from Cassia alata leaves collected in Can Tho, Vietnam.

Keywords: Cassia alata L., Folium Cassiae alatae, chemical constituents, anthraquinone, flavonoid.