ISOLATION AND CHARACTERIZATION OF STIGMASTEROL AND β-SITOSTEROL FROM Cassia sieberiana (FABACEAE) LEAF EXTRACT

Abstract

Phytochemical screening of the leaf extract of Cassia sieberiana revealed the presence of steroids, terpenes, flavonoids, saponins, reducing sugars, terpenoids, anthraquinones, tannins and glycosides. The research characterized and elucidated the bioactive principles from the leaf extract of the plant. Purification and various chromatographic techniques: Column & thin layer chromatography of the crude extracts led to a number of fractions. Isolation and characterization afforded white crystalline powder which was subjected to 1-D and 2-D NMR spectral analysis and identified as a mixture of Stigmasterol and β Sistosterol; differentiated only at C22 and C23.The 1H-NMR spectrum of compound Stigmasterol and β Sstosterol varied between δ 0.69 to δ 5.35. In the spectrum, H-3 proton appeared as a multiplet at δ 3.52, and H-6 olefinic proton showed a doublet at δ 5.35. Two olefinic protons appeared down the field at δ 5.01(dd) and δ 5.15(dd) which were identified with the chemical shift of H-22 and H-23 respectively, six methyl protons also appeared at δ 1.01, δ 0.80, δ 0.92, δ 0.84, δ 0.82 and δ 0.69.as identified by Hâ€NMR.Stigmasterol / sistosterol is a phytosterol having potential to reduce the risk of cardiovascular diseases. Thus rendering reduction in blood LDL cholesterol and confirming folkloric information of the usage of the plant as a remedy for diabetes and  other common maladies. Key words: Cassia sieberiana, phytochemical, characterization, structural elucidation, and stigmasterol / β-sitosterol