Isolation and Characterisation of Stigmasterol and Β -Sitosterol from Odontonema Strictum (Acanthaceae)

Abstract

Phytochemical screening of the extracts obtained from the leaves of Odontonemastrictum, a plant used in folklore medicine in Burkina-faso for its anty-hypertensive properties, indicated the presence of: flavonoids (type of flavones), saponins, glycosides, tannins, steroids and terpenoids. Column chromatography of the crude extracts lead to a number of fractions. TLC fingerprinting and the spraying reagent (Concentrated H₂SO₄ and vanillin in methanol) were used to identify the fraction containing phytosterols. The isolation and purification afforded white crystalline powder which was subjected to physical, chemical and spectral identification by IR, 1H‐NMR, 2D-NMR and 13C‐NMR. The compound was identified as a mixture of stigmasterol and β‐sitosterol.