Studies on the Effect of Extraction Method on Chemical Composition and Antimicrobial Activity of Carum copticum Essential Oil

By application of different methods of extraction, variations in the extraction rate and chemical composition of the extracted essential oils might be observed. Essential oil of Carum copticum cultivated in Iran was obtained by hydrodistillation (HD) and microwave free solvent (SFME). Oils were analyzed by GC/MS and a firm identification of the components were preformed by comparison of relative retention indices and mass spectra with authentic reference(1).. Eleven components 99.31% were identified in the oil which was isolated by hydrodistillation. The major components of oil of C.copticum were γ-terpinene (37.40%), p-cymene (28%), thymol (24.96%), β- pinene (5.78 %.), myrcene (1.31%). Eleven components (96.91%) were characterized in the oil which was obtained by free-solvent microwave extraction. The major components of the oil were thymol (35.28), γ- terpinene (32.49%), p-cymene (23.51%), β-pinene (3.47%), carvacrol (2.46). Antimicrobial activity of the essential oils were examined against Escherichia coli, using Agar dilution method and minimum inhibitory concentration (MIC) was preformed at 500ppm.