Abstract

Samuel Ehiabhi Okhale*, Grace Eyineyi Ugbabe, Ibrahim Abubakar, Shehu Busu Mohammed, Henry Omoregie Egharevba, Aliyu Adamu, Jemilat Aliyu Ibrahim, Oluyemisi Folashade Kunle

ABSTRACT

The leaf of Erythrophleum suaveolens (E. suaveolens) is applied to wounds and also used to repel pest and insects. However, there is no report on the chemical composition of the leaf essential oil of the plant. This study aims to determine the chemical composition and antimicrobial activity of the essential oil of the leaf of E. suaveolens. The essential oil was obtained by hydrodistillation method with the aid of a Clavenger type apparatus. The GC-MS analysis of the essential oil was done using Shimadzu QP- 2010plus GC-MS. Individual constituents were identified by comparing their mass spectra with known compounds and NIST Mass Spectral Library. The antibacterial activities of the essential oil against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli, Candida albicans and Mycobacterium bovis were evaluated using microdilution broth method using 96-well microplates. Ciprofloxacin and Fluconazole were used as the standard drugs. The minimum inhibitory concentration (MIC) value of the essential oil was also determined. The GCMS analysis showed that the oil contained 10 compounds with ?-citral, ?-citral and squalene as the major compounds at 36.96%, 25.41% and 20.07% respectively. Other constituents were ?-linalool (4.06 %), ?-thujenal (3.73 %), hydroxylneoisolongifolane (2.91%), ?-myrcene (1.85%), 2-hydroperoxyhexane (1.82%), ?-farnesene (1.61%) and 1,2-epoxy-3-propoxy propane (1.59%). The antimicrobial assay showed that the essential oil possessed antimicrobial activity against E. coli with an MIC of 25?g/ml. The isomeric composition of citral in E. Suaveolens is 59.3% ?-citral and 40.7% ?- citral. The antimicrobial activity of the oil against E. coli may be due to high content of citral.