Synthesis of the oxazolone derivatives was achieved by the condensation of aromatic aldehydes with N-acetyl glycine in the presence of acetic anhydride and anhydrous sodium acetate. A total of six oxazolones were 1 13 synthesized and characterized using H-NMR, C-NMR and FT-IR spectroscopic techniques. The synthesized compounds were screened for their in vitro antibacterial and antifungal activities using streptomycin and ampicillin as control. The result showed that some of the compounds demonstrate good antibacterial activities against specific bacterial strains and moderate activities against other bacterial strains. The compounds did not show any sensitivity against the tested fungal strains. The quantitative structure-antibacterial activity relationship was studied using some quantum chemical parameters with the aid of Spartan 10 (V1.0.1) and XLSTAT (add-in) software. A good correlation was observed between the antibacterial activity of the compounds and the calculated quantum chemical descriptors.

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Introduction: The history of the relationship between man and plants is as old as creation and man has used plants for different purposes including food and medicines. In this dispensation, man has been able to classify plants into food and medicinal plants and has also discovered that solution to his health problem comes from nature. Objectives: The antibacterial activities of the dichloromethane (DCM) and aqueous (AQU) fractions of acetone extract of Dacryodes edulis leaf were investigated against both Gram positive and Gram negative bacterial organisms made up of locally isolated and standard strains. Materials and Methods: About 1 kg of the powdered leaves of D. edulis was extracted at room temperature (25-27oC) using 75% acetone for 3 days. The mixture was then filtered and the filtrate was dried in vacuo using a rotary evaporator (insert the make and model). The crude extract was successfully partitioned using organic solvents in order of their polarity, that is, n-Hexane, DCM, n-Butanol, Ethylacetate. The sensitivity testing of the extracts against the organisms was determined using agar-well diffusion method as described by Irobi et al. [1]. Results: DCM and aqueous (AQU) fractions possessed closely related broad spectrum antibacterial activities and greater activity than the control standard antibiotics (Streptomycin and Ampicillin). The zones of inhibition exhibited by AQU fraction ranged between 20 and 30 mm while that of DCM fraction ranged between 22 and 32 mm. On the other hand, the zones of inhibition observed for the standard antibiotics, streptomycin ranged between 10 and 20 mm and ampicillin between 11 and 27 mm. The MIC and MBC of both fractions had range values between 0.78 and 6.25 mg/mL, evaluation of phytochemical composition of D. edulis revealed alkaloid (30.63 mg/g), terpenoid (19.72 mg/g), saponins (10.54 mg/g), tannin (9.14 mg/g), flavonoid (6.51 mg/g) and glycoside (6.29 mg/g) which are very significant antibacterial agents in medicinal plants. Conclusion: This work indicates that the two fractions had better antibacterial potentials than the standard antibiotics used.

Dacryodes edulis is a fruit tree attaining a height of 18–40 meters mostly grown around the house and rarely in the forest. It has a relatively short trunk and a deep, dense crown and it is native to Africa hence often called African pear. The leaves are a compound with 5-8 pairs of leaflets. Acetone extract/solvent fractions of the leaves of Dacryodes edulis were used. The in vitro antibacterial activities and rate of kill of different fractions were investigated. The phytochemical screening was done by some chemical tests, antibacterial activity by agar well diffusion method and rate of kill was carried out on S. aureus and E. coli organisms. The fractions exhibited antibacterial activities with zones of inhibition ranged between 20 and 30 mm by Aqueous (AQU) fraction while Dichloromethane (DCM) fraction ranged between 22 and 32 mm. The standard antibiotics, streptomycin ranged between 10 and 20 mm and ampicillin between 11 and 27 mm. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of both fractions had range values between 0.78 and 6.25 mg/mL. The phytochemical screening revealed the presence of alkaloids, tannins, saponins, flavonoids, terpenoid and glycoside. Overall, the two fractions had better activities than the standard antibiotics used. The time kill assay showed that the percentage of the cells killed increased with increasing concentrations of the fractions, as well as, contact time intervals. The AQU fraction killed 100% of Escherichia coli and Staphylococcus aureus cells at concentration of 4.68 mg/mL (3 X MIC) within 120 min while DCM fraction killed 100% of Escherichia coli cells within 90 min at a concentration of 4.68 mg/mL and killed 100% of S. aureus cells within 120 min at a concentration of 3.12 mg/mL (2X MIC). In conclusion, D. edulis leaf fraction has a broad spectrum antibacterial activity, with the AQU and DCM fractions being bactericidal as exemplified by the killing rate and MIC index of 2 (ratio of MBC/MIC) for both fractions.