ANTIBACTERIAL ACTIVITY OF SOME SELECTED SUBSTITUTED BENZALDOXIMES

Abstract

This study deals with the synthesis of some selected substituted benzaldoximes from their corresponding benzaldehydes by the reaction of the alcoholic solution of the substituted benzaldehydes with hydroxylamine in the presence of sodium hydroxide (NaOH) using ethanol/water solution as solvent medium. Structural elucidation of the synthesized compounds was carried out by infrared spectroscopy (IR) and Gas Chromatography-Mass spectroscopy (GC-MS) analysis and the assigned structures are in agreement with spectral data obtained. The study revealed that this synthetic route afforded bezaldoximes in good yields (74-79%). The synthesized compounds (5a-d) were screened for their antibacterial activities against one Gram-positive bacteria (Bacillus subtilis strain AIMST 2ME11) and three Gram-negative bacteria (Pseudomonas aeruginosa strain PG1 and Pseudomonas aeruginosa Strain 333K35 and Escherichia coli). Their zones of inhibition were measured, and the results showed that compound 5a has no activity against all four bacteria isolates used for the study. Compounds 5b-d showed antibacterial activity with compound 5d having the maximum antibacterial activity at low concentrations of 50-25mg/ml against all four bacteria isolates compared to the control ampicillin (except against Escherichia coli).  Keywords: Antibacterial, Substituted Benzaldoximes, Hydroxylamine hydrochloride, Benzaldehydes