CHEMICAL COMPOSITION AND ANTIMICROBIAL ACTIVITIES OF TWO AROMATIC PLANTS: Origanum majorana L. AND  O. compactum

Malika  CHARAI  and   Mahjouba  MOSADDAK

ABSTRACT

The essential oils obtained by steam distillation of  Origanum comapctum and O. majorana)  which  were grown in Morocco were examined by gas ­chromatography to determine their major constituents. The major constituents of O. compactum were carvacrol (49.52%), p-cymene (21.22 %) and -terpinene (14.21 %) while the major constituents of the O.majorana oil were linalool (32.68 %) and terpinen-4-ol (32.30%). The oils, dried whole plants, and aqueous exracts 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.