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, 1H NMR, 13C 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 1 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.