Abstract

The report focused on the extraction of oilseeds of Desbordesia glaucescens (Engl.) Tiegh. from Gabon as well as on the phytochemical study and evaluation of the anti-free radical activity of the extracts obtained. The extraction was carried out by cold maceration with solvents of increasing polarities: hexane, tricholroethylene, acetone, ethanol and distilled water. The anti-free radical activity was measured by scavenging the free radical cation of 2,2'-azinobis [3-ethylbenzothiazolin-6-sulfonic acid] (ABTS • +) with gallic acid as the standard antioxidant. Total extraction yields were in the order of 82.31%. Phytochemical tests demonstrated the presence of secondary metabolites of alkaloids, tannins, polyphenolstypes, reducing compounds, free anthracene derivatives, anthraquinones, total sugars, coumarins, free quinones, sterols and terpenes, carotenoids, flavonoids, cardiac glycosides, mucilages, saponins and leucoanthocyanins. The results of the anti-free radical activity showed that the polar extracts were much more anti-free of the free radicals than the non-polar extracts. The aqueous extract was the most active with an IC50 of 10 µg. mL-1, followed by ethanolic extract with IC50 of 14 µg. mL-1 and acetone extract with IC50 of 150 µg. mL-1. Cyclohexane and trichlorethylene extracts were more or less inactive. Gallic acid, the standard antioxidant, showed an IC50 of 0.37 µg. mL-1.

Key words: Desbordesia glaucescens, oil seeds, extracts, phytochemical tests, anti-radical activity, ABTS test.