Essential oil compounds of Croton pseudopulchellus and Croton gratissimus were analysed using Gas Chromatography/Mass Spectrophotometry and screened for antimicrobial activity against Bacillus pimitus (ATCC 29212), Bacillus cereus (ATCC 10702) Staphylococcus aureus (ATCC 3983), Streptococcus faecalis (ATCC 29212), Escherichia coli (ATCC 4983), Klebsiella pneumoniae (ATCC 2983) and Pseudomonas aeruginosa (ATCC 19582) using Agar gel disk diffusion test and minimum inhibitory concentrations. The susceptibilities of all isolates of different essential oil compounds were standardised by National Committee for Clinical Laboratory Standards (NCCLS) 1998). The cytotoxicity test was also carried out to determine the toxicity levels of essential oil compounds. These plants were selected based on their use by traditional healers for treatment of upper respiratory tract, gastrointestinal tract and urinary tract infections. The essential oil compounds of C. pseudopulchellus and C. gratissimus were found to be active against all the test microorganisms, while the preliminary assessment of essential oil compounds from these plants exhibited low cytotoxic activity.
Keywords: essential oil; sesquiterpenes; chemical composition; antimicrobial activity