Hakan Özer

Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene

The chemical composition of essential oil isolated by hydrodistillation from the aerial parts of Origanum acutidens was analyzed by GC-MS. Carvacrol (87.0%), p-cymene (2.0%), linalool acetate (1.7%), borneol (1.6%) and beta-caryophyllene (1.3%) were found to be as main constituents. Antifungal, phytotoxic and insecticidal activities of the oil and its aromatic monoterpene constituents, carvacrol, p-cymene and thymol were also determined. The antifungal assays showed that O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of 17 phytopathogenic fungi and their antifungal effects were higher than commercial fungicide, benomyl. However, p-cymene possessed lower antifungal activity. The oil, carvacrol and thymol completely inhibited the seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus and also showed a potent phytotoxic effect against these plants. However, p-cymene did not show any phytotoxic effect. Furthermore, O. acutidens oil showed 68.3% and 36.7% mortality against Sitophilus granarius and Tribolium confusum adults, respectively. The findings of the present study suggest that antifungal and herbicidal properties of the oil can be attributed to its major component, carvacrol, and these agents have a potential to be used as fungicide, herbicide as well as insecticide.

Antioxidant properties and total phenolic content of eight Salvia species from Turkey.

Methanolic extracts of eight Salvia species, namely S. aethiopis, S. candidissima, S. limbata, S. microstegia, S. nemorosa, S. pachystachys, S. verticillata, and S. virgata, sampled from Eastern Anatolia in Turkey, were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and beta-carotene/linoleic acid. Total phenolic content of the extracts of Salvia species were performed Folin-Ciocalteu reagent and gallic acid used as standard. A wide variation has been observed among species in terms of antioxidant activity and total phenolic content. In both DPPH and beta-carotene system, the most active plant was Salvia verticillata with a value of IC50=18.3 microg/ml and 75.8%, respectively. This species also has the highest total phenolic content (167.1 mgGAE/g DW). The total amount of phenolics was between 50.3 to 167.1 mgGAE/g DW among species. A positive linear correlation was observed between total phenolic content and antioxidant activity of the extracts. The results suggest that the extract of Salvia species, notably Salvia verticillata with the highest antioxidant activity, can be used as natural antioxidants in the food industry.

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria

BACKGROUND The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC-MS, and to test antibacterial efficacy of essential oils and n-hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS Thymol, carvacrol, p-cymene, thymol methyl ether and gamma-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, delta-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n-hexacosane, n-tricosane and n-heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. CONCLUSION Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant.

Antimicrobial Activities of Essential Oil and Hexane Extract of Florence Fennel [Foeniculum vulgare var. azoricum (Mill.) Thell.] Against Foodborne Microorganisms

The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

Chemical composition of hydrodistilled essential oil of Artemisia incana (L.) Druce and antimicrobial activity against foodborne microorganisms.

The oil obtained by hydrodistillation from the aerial parts of Artemisia incana (L.) Druce from Turkey was analyzed by GC and GC/MS. Sixty‐three compounds were characterized, representing 97.2% of the total components detected, and camphor (19.0%), borneol (18.9%), 1,8‐cineole (14.5%), bornyl acetate (7.8%), camphene (4.9%), and α‐thujone (4.8%) were identified as predominant components. The essential oil was also tested for its antimicrobial activity against 44 different foodborne microorganisms, including 26 bacteria, 15 fungi, and 3 yeast species. The essential oil of A. incana exhibited considerable inhibitory effects against all bacteria, fungi, and yeast species tested. However, the oil showed lower inhibitory activity against the tested bacteria than the reference antibiotics.

Antimicrobial and antioxidant activity and chemical composition of the essential oil of Tanacetum macrophyllum (Waldst. et Kit.) Schultz. Bip.

Abstract The essential oil of Tanacetum macrophyllum growing wild in Turkey was obtained by hydrodistillation, and antimicrobial activity of the essential oil was tested against six bacteria and two yeasts including Candida albicans and Aspergillus niger by disc diffusion method. Further the oil of this plant was analyzed by GC and GC/MS technique. Best effect of the oil was against pseudomonas earuginosa. Twenty-eight components, representing 95.6% of the total oil, were identified. The main component of the oil was β-eudesmol (89.5%). The antioxidant activity of the essential oil was measured by the ferric reducing antioxidant power (FRAP) assay.

ESSENTIAL OIL COMPOSITION OF Tanacetum alyssifolium, AN ENDEMIC SPECIES FROM TURKEY

Faculty of Agriculture, Department of Field Crops, Erzurum 25240, Turkey; fax: + 9

Composition of the essential oil of Salvia longipedicellata from Turkey

2312493, e-mail: haozer@atauni.edu.tr; 2) Ataturk University, Faculty of Art and Science, Department of Chemistry, Erzurum 25240, Turkey; 3) Ataturk University, Faculty of Art and Science, Department of Biology, Erzurum 25240, Turkey; 4) Ataturk University, Biotechnology Application and Research Center, 25240, Turkey . Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 190-191, March-April, 2007. Original article submitted January 18, 2006.

Chemical Composition of the Essential Oil of Teucrium multicaule Montbret Et Aucher Ex Bentham from Turkey

Abstract The oil obtained by hydrodistillation from the aerial parts of Teucrium multicaule Montbret Et Aucher Ex Bentham from Turkey was analyzed by GC and GC/MS. Fifty-six compounds were characterized, representing 90.0% of the total components detected. The major constituents were identified as germacrene D (13.2%), caryophyllene oxide (10.9%), spathulenol (6.6%), β-caryophyllene (5.6%), and (6Z,10Z)-pseudo phytol (4.1%).

Chemical Composition of the Essential Oil of Tripleurospermum corymbosum E. Hossain, an Endemic Species from Turkey

Abstract The oil obtained by hydrodistillation from the aerial parts of Tripleurospermum corymbosum from Turkey was analyzed by GC and GC-MS. Forty-two compounds were characterized, representing 91.9 % of the total components detected. The major constituents were (Z)-β-farnesene (18.2 %), 1-epi-cubenol (16.1 %), β-patchoulene (8.5 %), α-Cadinene (7.2 %), β-sesquiphellandrene (6.4 %), (E)-γ-bisabolene (4.6 %) and dodecanoic acid (4.5 %).