Chemical composition and antimicrobial activity of essential oil of Verbena rigida Spreng.

The study was planned to determine the chemical composition and antimicrobial properties of the essential oil of Verbena rigida Spreng. cultivated in Egypt. The essential oil from aerial parts of Verbena rigida Spreng. was prepared by hydrodistillation in a yield of 0.26 % v/w. The chemical composition of the essential oil has been elucidated by gas chromatography-mass spectroscopy analysis. The prepared essential oil was tested against selected species of Gram-positive, Gram-negative bacteria and Candida species using disc diffusion method and MICs were determined using broth micro-dilution method. Twenty-eight compounds were identified in the essential oil of Verbena rigida, the major components were isobornyl formate (35.2%) and citral (32.9%). The essential oil showed significant antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillis subtilis, Escherichia coli and Pseudomonas aeruginosa with MIC 25 µg/mL for E. coli and 50 µg/mL for other sensitive bacteria. This is the first study of the chemical composition and antimicrobial activity of the essential oil of V. rigida, it proved that the essential oil of V. rigida possesses potential antimicrobial properties and could in the future represent a new source of natural antiseptic agents.