Antimicrobial activity and chemical composition of Origanum glandulosum Desf. essential oil and extract obtained by microwave extraction: Comparison with hydrodistillation

Abstract Origanum glandulosum Desf. essential oils obtained by hydrodistillation (HD), solvent-free microwave extraction (SFME) and the extract obtained by microwave-assisted extraction (MAE) were investigated by capillary gas chromatography and gas chromatography/mass spectrometry. The main components of both oils obtained by HD and SFME were thymol (41.6–81.1%) followed by γ-terpinene (27.0–3.1%), p-cymene (17.1–4.0%) and carvacrol (2.2–4.4%), respectively. In the same way, thymol (65.4%), γ-terpinene (13.1%), p-cymene (7.2%) and carvacrol (3.5%) were the main components of the extract obtained by hexane microwave extraction. The SFME method was most selective for the extraction of thymol. The examination of the antimicrobial activity of both essential oils against 10 bacteria, two yeasts and four moulds revealed that O. glandulosum oil is more antifungal than antibacterial. To our knowledge, the antifungal activity of the O. glandulosum oil obtained by HD and both antimicrobial and antifungal activities of O. glandulosum SFME oil were not yet reported. Our study suggests that O. glandulosum essential oil has the potential to be used as a food preservative and to prevent the growth of nosocomial bacteria.

[1]  A. Craveiro,et al.  Microwave oven extraction of an essential oil , 1989 .

[2]  M. Miloš,et al.  Catalytic Oxidation and Antioxidant Properties of Thyme Essential Oils (Thymus vulgarae L.) , 2005 .

[3]  Farid Chemat,et al.  Solvent-free microwave extraction of essential oil from aromatic herbs: comparison with conventional hydro-distillation. , 2004, Journal of chromatography. A.

[4]  J. H. Ietswaart.  A taxonomic revision of the Genus Origanum (Labiatae) , 1980 .

[5]  G. Flamini,et al.  Comparison between the conventional method of extraction of essential oil of Laurus nobilis L. and a novel method which uses microwaves applied in situ, without resorting to an oven. , 2007, Journal of chromatography. A.

[6]  S. Bradshaw,et al.  Solvent free microwave extraction of Elletaria cardamomum L.: A multivariate study of a new technique for the extraction of essential oil , 2007 .

[7]  O. Sağdıç,et al.  Antibacterial activity and composition of essential oils from Origanum, Thymbra and Satureja species with commercial importance in Turkey , 2004 .

[8]  J. Stewart,et al.  The potential application of plant essential oils as natural food preservatives in soft cheese , 2001 .

[9]  Wieland Peschel,et al.  An industrial approach in the search of natural antioxidants from vegetable and fruit wastes , 2006 .

[10]  S. Burt,et al.  Essential oils: their antibacterial properties and potential applications in foods--a review. , 2004, International journal of food microbiology.

[11]  E. L. Souza,et al.  Effectiveness of Origanum vulgare L. essential oil to inhibit the growth of food spoiling yeasts , 2007 .

[12]  I. Chinou,et al.  Composition and antimicrobial activity of the essential oils of two Origanum species. , 2001, Journal of agricultural and food chemistry.

[13]  F. Chemat,et al.  An original solvent free microwave extraction of essential oils from spices , 2004 .

[14]  Jacqueline M.R. Bélanger,et al.  Microwave-assisted process (MAP™): a new tool for the analytical laboratory , 1994 .

[15]  G. Ruberto,et al.  Chemical composition and antioxidant activity of essential oils from Algerian Origanum glandulosum Desf. , 2002 .

[16]  Eleni Papanikolaou,et al.  Antimicrobial and Cytotoxic Activities of Origanum Essential Oils , 1996 .

[17]  K. Başer,et al.  Genotoxicity and antigenotoxicity of Origanum oil and carvacrol evaluated by Ames Salmonella/microsomal test , 2005 .

[18]  A. Figueiredo,et al.  Origanum glandulosum Desf. grown wild in Algeria: essential oil composition and glycosidic bound volatiles , 2005 .

[19]  D. Biondi,et al.  Chemical composition, antimicrobial and antioxidant activities of the essential oil of several populations of Algerian Origanum glandulosum Desf. , 2006 .

[20]  G. Collin,et al.  Essential oils and microwave extracts of cultivated plants , 1992 .