Isolation of bioactive constituents from the ethylacetate leaf extract portion of Gmelina arborea (Verbenaceae)

Abstract

The medicinal value of plants has assumed important dimension in the past few decades owing mainly to the discovery that extracts from plants contain not only minerals and primary metabolites but also a diverse array of secondary metabolites with anti-inflammatory, antioxidant and antimicrobial potential. In Nigeria (West Africa), the decoction of the leaf extract of Gmelina arborea mixed with trona is taken as a remedy for Malaria fever, Typhoid as well as an antibacterial agent. The main objective of the present research was to carry out preliminary phytochemical and antimicrobial evaluation of the ethyl acetate portion of the leaf extract of Gmelina arobrea using standard protocols. Preliminary phytochemical screening revealed the presence of Alkaloids, Flavonoids, Saponins, Phenolic compounds, Triterpenes and Steroids. Compound 1 isolated was determined as 2-(2,4- dihydroxy-5-prenylphenyl)-5,6- methylenedioxybenzofuran, while compound 2 was determined as 5,7,2',4'-tetrahydroxy-8-lavandulyl-5'- methoxy flavone. Determination of the antimicrobial activity of the ethyl acetate portion on some isolates was conducted. The zone of inhibition from the antibacterial activity from the ethyl acetate portion was found to be fairly good against gram (+) bacteria e.g Staphlococcus aureus, Bacillus subtilis and gram (-) bacteria e.g Klebsiela pneumonia and Escherichia coli. The antifungal activity of the ethyl acetate portion was found to be active against Aspergillus niger, Fusarium moniliforme and Fusarium oxysorum. This study supports the folkloric claims for the use of Gmelina arborea against some bacterial caused infections.