Phytochemical Screening and Determination of Polyphenols in the Hydro-Ethanolic Extract of Trunk Bark and Its Fractions of Stereospermum kunthianium Cham (Bignoniaceae)

Abstract

Background : Stereospermum kunthianum Cham., is a medicinal plant from the Bignoniaceae family, used in Ferlo (Senegal) against stomach aches, as a healing agent and aphrodisiac. Aims/Objective : The aim of this study was to contribute to the valorisation of the plant by carrying out a phytochemical screening followed by an assay of the polyphenols of the hydro-ethanolic extract of the bark and its fractions. Methods : Phytochemical screening was carried out by coloring and/or precipitation reactions. The total polyphenol and tannin contents were evaluated by the Folin-Denis method and the flavonoid content by a method using aluminium chloride (AlCl 3 ) and sodium nitrite (NaNO 2 ). Results: The search for chemical compounds revealed the presence of various secondary metabolites such as gallic and catechic tannins, flavonoids, saponosides, alkaloids, sterols and polyterpenes. The total polyphenol contents of the samples ranged from 0.81 ± 0.02 to 13.52 ± 0.06 mg EAT / g. Those of tannins and flavonoids were between 0.03 ± 0.01 and 4.56 ± 0.02 mg EAT / g and between 1.13 ± 0.04 to 31.88 ± 0.19 mg ER / g respectively. Conclusion : These different metabolites would be responsible for the activities noticed for this plant.