Chemical Composition and Antimicrobial Activities of Two Aromatic Plants:Origanum majoranaL. andO. compactumBenth.

Abstract
The essential oils obtained by steam distillation of Origanum compactum and O. majorana, which were grown in Morocco, were examined by gas chromatography to determine their major constituents. The major constitutents of O. compactum were carvacrol (49.52%), p-cymene (21.22%) and γ-terpinene (14.21%), while the major constituents of the O. majorana were linalool (32.68%) and terpinen-4-ol (32.30%). The oils, dried whole plants, and aqueous extracts derived from the leaves were examined for their antimicrobial activities on molds, yeasts and bacteria. The Minimal Inhibitory Concentration (MIC) was determined in every case. A total inhibition (100%) was obtained with the O. compactum oil at the concentration of 4 ppm on all the microbial species, while O. majorana oil totally inhibited yeasts and lactic acid bacteria at a concentration of 5 ppm. Aqueous extracts of the two plants were less inhibitory than their essential oils. The entire plants were also inhibitory to some strains of yeasts, molds and bacteria, and O. compactum was more inhibitory than O. majorana.