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The antibacterial activity of compounds isolated from the stem bark and sawdust of Erythrophleum suaveolens were evaluated. Extraction of the pulverized plants materials was carried out using hexane, ethyl acetate and methanol. Extracts were fractionated using column chromatography and fractions were examined using Nuclear Magnetic Resonance spectroscopy. Antibacterial activities against Acidobacterium capsulatum, Actinobacterium sp., Agrobacterium tumefaciens, Bacillus subtili, Ralstonia solanacearum, Enterococcus faecium, Escherichia coli, Pseudomonas syringae, Pseudomonas aeruginosa and Proteus mirabilis were also carried out. A novel triterpene, 21-acetoxylupenone and betulin were identified in the fractions from the stem bark of E. suaveolens while cycloeucalenol and stigmasterol were obtained from the sawdust extract fractions. Pseudomonas aeruginosa was resistant to all control antibiotics but was inhibited by 21acetoxylupenone and cycloeucalenol with 23 mm and 24 mm diameter of Zones of Inhibition. Acidobacterium capsulatum, Actinobacterium sp., Agrobacterium tumefaciens, Ralstonia solanacearum, and Proteus mirabilis were completely inhibited at Minimum Bactericidal Concentration (MBC) of 50 µg/mL, while Bacillus subtilis, Enterococcus faecium, Escherichia coli, Pseudomonas syringae, and Pseudomonas aeruginosa were completely inhibited at MBC values of 100 µg/mL. Thus E. suaveolens stem bark and saw dust isolates can be used in the control of plants diseases where these pathogens are the causative agents.

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 (C H O). Antifungal 29 48 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 20 mm, 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.

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