The present work assessed the potential of cat thyme (Teucrium polium L.) chloroform extract as a source of natural antimicrobial compounds. Lipid constituents of this extract were analyzed by gas-liquid chromatography (GLC). The fatty acid analysis indicated palmitic (20.35%), stearic (19.15%), pentadecanoic (15.16%) and oleic (7.78%), linoleic (9.55%), linolenic (3.61%) acids were the most prevalent saturated and unsaturated acids, respectively. The unsaponifiable matter consisted of Cn (21.27%) and C27 (17.25%) as major hydrocarbons and l3-sitosterol (9.75%) as the major sterol. The phenolic compounds were analyzed by HPLC and the results showed that the predominant constituent was hydroquinone (26.47%) and the identified second main constituent was catechin (8.17%). Furthermore, apigenin was present as a trace constituent (0.92%). Preliminary screening of the antimicrobial activity of cat thyme (T. polium)
chloroform extract against some pathogenic and spoilage microorganisms representing some Gram-negative bacteria, Gram-positive bacteria, one yeast strain and eight fungal species were performed using disc-diffusion method. The extract was effective in inhibiting the growth of the organisms except for Escherichia coli, Enterobacter aerogenase, Bacillus megaterium and Aspergillus niger. Antimicrobial activity of the extract increased with increasing concentration. Additionally, antifungal activity of the extract was less potent than the antimicrobial activity.