Antimicrobial effect of isolated compound of Anadelphia afzeliana (Rendle) Stapf on selected wood fungi and bacteria in Makurdi, Nigeria

Abstract

Anadelphia afzeliana was assessed for antimicrobial activity as an alternative to synthetic chemicals. A. afzeliana was collected from Orkar village, Gboko, Benue State. The specimen was pulverized. Methanol, ethyl acetate, and n-hexane solvents were used for extraction. Each solvent measured 1800 ml was added to 300 g of A. afzeliana. The mixture was left to soak for 48 hours. Extract was filtered and allowed to dry by evaporation. Dried extract was mixed with silica gel to run column chromatography. Compounds were analysed by Nuclear magnetic resonance (NMR). Concentrations of 200, 100, 50 and 12.5 μg/m were constituted for antimicrobial sensitive test on ten wood bacteria and nine fungi. NMR showed the presence of stigmasterol (C₂₉H₄₈O). Antifungal test revealed A. fumigatus, C. puteana, G. sepiarium, P. schweinitzii, Rhizopus spp. and S. rolfsii as sensitive to stigmasterol at zones of inhibition (ZOI) of 19, 21, 22, 23, 24 and 20mm, respectively. Antibacterial showed A. proteobacteria, B. subtilis, B. proteobacteria, E. faecium, E. coli, P. aeruginosa and P. mirabilis sensitive at ZOI of 30, 28, 29, 26, 27, 23, and 23 mm, respectively. Minimum inhibition concentration (MIC) of 25 μg/ml completely inhibited Alpha proteobacteria, Bacillus subtilis and Beta proteobacteria while Minimum Bactericidal Concentration (MBC) of 50 μg/ml completely killed A. proteobacteria, B. subtilis, and B. proteobacteria. MIC of stigmasterol at 50 μg/ml completely inhibited Coniophora puteana, Gloeophyllum sepiarium, Phaeolus schweinitzii, Rhizopus spp. and Sclerotium rolfsii while at 100 μg/ml of Minimum fungicidal concentration (MFC), Phaeolus schweinitzii and Rhizopus spp. were completely killed. A. afzeliana proved potent in the control of wood fungi and bacteria. MFC and MBC for tested pathogens were observed to be most effective at 50 μg/ml and is therefore recommended as concentration for A. afzeliana compound in the control of fungi and bacteria infections.

Keywords: Anadelphia afzeliana, bacteria, fungi, stigmasterol, sensitive, resistant