Abstract

CSA Bopenga Bopenga*, Ella Nkogo Ley-Fleury, Edou Engonga Prosper, Ngohang Franck Estim

Our work focused on the study of the extract rates, phytochemical and anti-termite tests of the bark of Guibourtia tessmannii from Gabon commonly called Kévazingo on two levels, the buttress and at a height of 6 m. Extraction of the bark powders was carried out using the cold maceration method with tricholroethylene, acetone, ethanol and water. The phytochemical screening made it possible to highlight groups of chemical families present in the extracts. Anti-termite activity was evaluated in wild termites of the genus Isoptera. The following extracts yields were obtained: 17.11% for the buttress and 13.42% for the height at 6 m. Phytochemical tests revealed in the extracts the presence of alkaloids, polyphenols, sterols, tannins, reducing compounds, flavonoids, saponins, anthraquinones. The results obtained indicated that the anti-termite activity varies with the different parts of the bark studied, the extraction solvent and the concentration (50/50) and (25/75) of the extracts used. The extracts at the concentrations (50/50) showed a slightly better anti-termite activity compared to (25/75) and the buttress kevazingo showed the strongest anti-termite activity for the aqueous extract with a survival rate of 0 % after 2 days.