Ridwan Olanrewaju IsmaeelSaliu Bolanle KudiratLamidi Ajao UsmanFatihat HassanOyeleye Medinat AdedejiEtimbuk Daniel AkpanSambo Ameen Olanrewaju Fadhilat2025-04-292025-04-292025-02-21Crassocephalum, crepidiodes, Staphylococcus, aureus, D- limonene2958-9630https://uilspace.unilorin.edu.ng/handle/123456789/15680This study was carried out to isolate and evaluate the antibacterial activity of the leaf essential oil of Crassocephalum crepidiodes against selected bacteria. Hydrodistillation of 500 g of sample of the plant’s leaves (for four hours) gave a yield of 0.10 %(w/w) of volatile oil. The oil was characterized using GC-MS and the result showed abundant of monoterpenoids in the oil and D-limonene (77.1 %) was the predominant constituent. Meanwhile, linalool (2.6 %), α-pinene (5.5 %), β-caryophyllene (2.4 %), and α-terpineol (2.6 %) were minor relative to the amount of limonene but are significant constituents of the oil. The agar well diffusion method was used to determine the antibacterial activity of the oil against Enterococcus faecalis, Bacillus cereus, Staphylococcus aureus, Streptococcus pneumoniae, Salmonella typhi and Salmonella sp. Gram-positive bacteria were more susceptible to the oil than Gram-negative bacteria. S. aureus was the most susceptible to inhibition at the lowest concentration (25 %) used in this study. Therefore, the oil has applications for the treatment of infections caused by the Gram-positive bacteria, especially S. aureus.enArticle