Phytochemical study of the extracts of oilseeds of Staudtia kamerunensis var. gabonensis (Warb.) from Gabon and evaluation of their antiradical activity

Abstract

The report focused on phytochemical tests and evaluation of the antiradical activity of seed extracts of Staudtia kamerunensis var. gabonensis . The successive extraction of seed powders from S. kamerunensis var. gabonensis was carried out by maceration at room temperature with solvents of increasing polarities: Cyclohexane, trichlorethylene, acetone, ethanol and distilled water. The antiradical activity was measured by trapping the radical cation of 2,2'-azinobis [3-ethylbenzothiazoline-6-sulfonic acid] (ABTS•+) with gallic acid as reference antioxidant. The total extraction yields were the order of 44.6%. Phytochemical tests demonstrated the presence of secondary metabolites of alkaloids, tannins, polyphenols types, reducing compounds, free anthracene derivatives, anthraquinones, total sugars, coumarins, free quinones, sterols and triterpenes, carotenoids, flavonoids, mucilages and traces of cardiac glycosides and saponins. The results of the anti-free radical activity showed that the polar extracts were much anti-free of the free radicals than the non-polar extracts. The ethanolic extract was the most active with an IC 50 of 20 µgmL -1 , followed by the aqueous and acetone extracts with IC 50 of 25 µgmL -1 . The cyclohexane and trichlorethylene extracts have lower antiradical activities with IC 50 of 400 µgmL -1 . Gallic acid, the reference antioxidant, showed an IC 50 of 0.37 µgmL -1 .