Chemical Composition and Antimicrobial Potential of n-hexane and Methanol Extracts of Benue Propolis

Published in [Frontiers in Physical and Applied Sciences (FIPAS)]: [https://journals.fuwukari.org.ng/index.php/fpas/article/view/6] ABSTRACT Propolis is a resinous material made by honey bees for protecting their hives against microbial attack. Propolis sample was collected from Kwande Local Government Area of Benue State. This study investigated the chemical constituents and antimicrobial activity of the crude extracts using gas chromatography–mass spectrometry (GC–MS) and in vitro susceptibility assays. Propolis sample was extracted using n-hexane, ethyl acetate and methanol. Antimicrobial evaluation against nine bacterial and four fungal strains demonstrated broad-spectrum activity significantly for the n-hexane and methanol extracts, with significant inhibition of Staphylococcus aureus (25±0.03 mm, 20±0.04 mm) and Pseudomonas aeruginosa (21±0.03 mm, 17±0.01 mm) by n-hexane, and methanol extracts, respectively. Moderate activity was observed against Escherichia coli (18±0.01 mm, 20±0.04 mm). The minimum inhibitory and bactericidal concentration (MIC/MBC) of the crude extracts of the inhibited bacteria ranged from 1.57 – 25 mg/mL. Significant antifungal activity was recorded against Candida krusei (24±0.02 mm) with the minimum fungicidal concentration of 1.57 mg/mL. GC–MS analysis of the extracts revealed a complex mixture of hydrocarbons, fatty acids, esters, alcohols, terpenoids, phenolics, and steroidal compounds. The methanol extract showed majorly 9,12-octadecadienoic acid (51.65%), alongside hexadecanoic acid (14.30%), glycerin (7.73%) and hydroquinone. Batilol and pregnane were reported for the first time in Nigerian Propolis. N-hexane extract was characterized by hydrocarbons and sesquiterpenes. These findings demonstrate that Benue Propolis possesses a phytochemical profile with significant antimicrobial potential, which can serve as promising source of bioactive compounds for therapeutic and drug development applications.