Isolation of chemical constituents from n -hexane leaf extract of Cassia singueana del. (Fabaceae)

Cassia singueana Del. (Fabaceae) is a tropical plant species widely distributed across northern Nigeria. It is used by traditional herbalists in the treatment of ulcer, diabetes and other diseases. In this work, the n-hexane leaf extract of C. singueana was fractionated and purified by column chromatography using n -hexane, CHCl 3 , and EtOAc. This process led to the isolation of five (5) compounds namely, stigmasterol ( 1 ), stigmast-4-en-3-one ( 2a ), stigmast-4, 22-dien-3-one ( 2b ), 1-heneicosanol ( 3 ) and hexyl heneicosanoate ( 4 ). Compounds 2a and 2b were isolated as mixture. The structures of the isolated compounds were elucidated using 1D and 2D NMR spectral analysis and comparison of the spectral data with literature values was undertaken. Keywords: Cassia singueana , column chromatography, isolation, phytochemicals, stigmasterol