Chemical constituents of the stem bark of Prunus africana and Evaluation of their Antibacterial Activity

Abstract

Chromatographic separation of the methanolic extract of Prunus africana stem bark led to the isolation of five compounds (β- sitosterol (1), benzoic acid (2), two oleanolic derivatives (3 and 4), and p-hydroxybenzoic acid (5). The structures of compounds were elucidated based on 1D and 2D NMR spectral data and compared with reported literature values. This is the first report of benzoic acid and its derivatives from the genus Prunus. The crude extract and isolated compounds were evaluated for their antibacterial activity against five bacterial strains (E. coli, S. aureus, S. flexineri, S.typhimurium, and P. aeruginosa) using disc diffusion assay and showed good antibacterial activity against the tested strains. The crude extract showed potent activity (21.03 + 0.05 mm) against P. aeruginosa, which is even greater than the reference drug gentamycin (14.06 + 0.09 mm). The antibacterial activity of P.africana extract and isolated compounds supports its traditional use, suggesting that it could be considered as a source of bioactive compounds in antimicrobial drug development.

Keywords

• Prunus africana
• oleanolic acid derivatives
• benzoic acid
• p-hydroxyl benzoic acid
• β- sitosterol
• antibacterial activity

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