Phytochemical and Antimicrobial Activities of Maerua Angolensis Plants

The increasing prevalence of antimicrobial resistance has intensified the search for alternative sources of bioactive compounds, particularly from medicinal plants.This study investigated the phytochemical composition, extraction recovery, antimicrobial activities, and secondary metabolites of Maerua angolensis plant using different solvent extracts.The was plant extracted successively with dichloromethane (DCM), ethyl acetate, and methanol, and the resulting extracts were evaluated for percentage recovery, phytochemical constituents, antimicrobial activity, and minimum inhibitory, bactericidal, and fungicidal concentrations.The highest extraction yield was obtained with methanol (30.30g; 3.03%), followed by ethyl acetate (7.20 g; 0.72%) and DCM (2.30 g; 0.23%).Preliminary phytochemical screening revealed the presence of alkaloids, terpenoids, flavonoids, phenols, and tannins in varying proportions among the extracts, whereas saponins were not detected in any of the extracts.The ethyl acetate extract showed the broadest phytochemical profile, with alkaloids, terpenoids, flavonoids, phenols, and tannins all detected.Antimicrobial evaluation against Escherichia coli, Salmonella spp., Candida spp., Staphylococcus spp., Pseudomonas spp., and Bacillus spp.demonstrated solvent-dependent and organism-specific activities.The DCM extract (MAD) exhibited selective antifungal activity against Candida spp., with inhibition zones increasing from 18 mm at 200 mg/mL to 26 mm at 400 mg/mL, corresponding to a MIC of 200 mg/mL and an MFC of 400 mg/mL.The ethyl acetate extract (MAE) showed activity against Salmonella spp.and Pseudomonas spp., producing inhibition zones of 27 and 22 mm, respectively, at 400 mg/mL, with MIC values of 400 mg/mL for both organisms.The methanol extract (MAM) exhibited activity against all six test organisms by the agar diffusion assay.At 400 mg/mL, inhibition zones were 15 mm for E. coli, 15 mm for Salmonella spp., 20 mm for Candida spp., 20 mm for Staphylococcus spp., 14 mm for Pseudomonas spp., and 15 mm for Bacillus spp.MIC values of 400 mg/mL were recorded for E. coli and Salmonella spp., while no MIC was detected for the other organisms under the tested conditions.MFC values were not detected for the tested extracts and organisms except for Candida spp.treated with MAD.The findings demonstrate that M. angolensis stem bark contains diverse secondary metabolites with appreciable and solvent-dependent antimicrobial activities.The results further indicate that extraction solvent strongly influences both the recovery and biological activity of plant constituents.The ethyl acetate and DCM extracts demonstrated selective activities against specific organisms, while the methanol extract exhibited the broadest activity in the diffusion assay.These findings support M. angolensis as a promising source of biologically active secondary metabolites and provide a basis for further chromatographic separation, LC-MS/UPLC profiling, structural characterization using MS, NMR and IR spectroscopy, and bioactivity-guided evaluation of purified compounds.