Isolation and antimicrobial activity of two phenolic compounds from Pulicaria odora L.

The essential oil of Pulicaria odora, a Moroccan medicinal plant; was analyzed by GC-MS, and subjected to column chromatography on silica gel. Two major constituents were isolated and identified as 2-isopropyl-4-methylphenol (1) and isobutyric acid 2-isopropyl-4-methylphenylester (2), by analysis of spectroscopic data (MS, H-1 NMR, C-13 NMR, DEPT, COSY, HMQC and HMBC experiments). The isolated compounds are reported for the first time from Pulicaria genus. The essential oil and its major constituents (compounds I and 2) were examined for antibacterial and antifungal activity in vitro using the diffusion and dilution methods. Results showed that the essential oil and the 2-isopropyl-4-methylphenol (1) exhibited a very significant antibacterial and antifungal activity, while the isobutyric acid 2-isopropyl-4-methylphenylester (2) was inactive for all tested strains. (c) 2005 Elsevier Ireland Ltd. All rights reserved.