The Yield and Composition of Dill Essential Oil in Relation to N Application, Season of Cultivation and Stage of Harvest

The effect of nitrogen (N) fertilization, season of cultivation and stage of harvest on the growth, foliar essential oil composition and yield of dill (Anethum graveolens L. cv. Ducat) was studied in two consecutive crops. Seeds were sown in October (autumn-winter crop) and January (spring crop) and the plants transplanted to a substrate of peat and perlite (1:1 v/v) 30 and 39 days later, respectively. Nitrogen (NH4NO3) was applied weekly at four levels (50, 150, 300, 450 ppm) in a completely randomized design. The plants were harvested at 158 (autumn-winter crop) and 83 (spring crop) days after sowing. The plant foliage was weighed and the essential oils were isolated by hydro-distillation and analyzed by GC/MS. The foliage fresh weight per plant progressively increased with increasing N up to 450 ppm in the autumn/winter, but was maximal at 300 ppm N in the spring. The essential oil concentration within the foliage was low and was unaffected by N application in the autumn/winter, but was significantly higher at 300 ppm N than at other N levels in the spring. The main components of the foliar essential oil were α-phellandrene, β-phellandrene, dill ether, α-pinene, β-pinene, α-thujene, myrcene, and π-cymene. In both crops α-phellandrene was the principal constituent. In the spring the concentration of all the essential oil constituents identified (except π- cymene) was highest at 300 ppm N, whereas in the autumn/winter crop the concentrations of α-phellandrene, β-phellandrene and dill ether were also higher at 300 ppm N, but the other constituents were not affected by higher N. It is concluded that for the autumn/winter crop 450 ppm N is optimal for biomass and foliar oil yield (biomass x oil concentration) whereas in the spring 300 ppm N is recommended

Composition of the essential oil of Achillea schischkinii Sosn. (Asteraceae) from Turkey

The aerial parts of Achillea schischkinii were water distilled to produce oil, which was analyzed by GC, and GC/MS. Thirty-one components were identified representing the 91.5% of the oil. The main components were 1,8-cineole (31.0%) and camphor (20.0%)

In vitro antimicrobial and antioxidant activities of the essential oils and various extracts of Thymus eigii M. Zohary et P.H. Davis

This study was designed to examine the in vitro antimicrobial and antioxidant activities of the essential oil and various extracts obtained from aerial parts of Thymus eigii. The essential oil was particularly found to possess stronger antimicrobial activity, whereas other nonpolar extracts and subfractions showed moderate activity and polar extracts remained almost inactive. GC-MS analysis of the oil resulted in the identification of 39 compounds, representing 93.7% of the oil; thymol (30.6%), carvacrol (26.1%), and rho-cymene (13.0%) were the main components. The samples were also subjected to a screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. In the former case, the polar subfraction of the methanol extract was found to be superior to all extracts tested, only 16.8 mug/mL of which provided 50% inhibition, whereas all extracts, particularly the polar ones, seem to inhibit the oxidation of linoleic acid in the latter case. These data were further supported by total phenolics analysis, indicating that the antioxidative potential of the extracts was closely related to their phenolic constituents

Thein vitro antioxidant and antimicrobial activities of the essential oil and various extracts ofOriganum syriacum L varbevanii

The present work examines the in vitro antioxidant and antimicrobial properties of the essential oil and various extracts from the herbal parts of Origanum syriacum L var bevanii. Polar subfractions of methanol extracts from both deodorised and non-deodorised materials showed the highest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, with IC50 values of 21.40 and 26.98mug ml(-1) respectively, whereas the IC50 of the essential oil was 134.00 mug ml(-1). The antioxidant potential of the extracts appeared to be closely related to the presence of polar phenolics. However, the inhibitive effect on linoleic acid oxidation might be promoted by the presence of non-polar phenolics, as both hexane and dichloromethane extracts showed high antioxidant activities. The antimicrobial activity of the essential oil was superior to those of the other extracts. Nineteen compounds representing 962 g kg(-1) of the essential oil were identified; carvacrol (669 g kg(-1)) was the main component. Overall, the results suggest that the essential oil and extracts from the herbal parts of 0 syriacum could be used as natural preservative ingredients in the food industry. (C) 2004 Society of Chemical Industry

Composition of the essential oils of Tanacetum argyrophyllum (C. Koch) Tvzel. var. argyrophyllum and Tanacetum parthenium (L.) Schultz Bip. (Asteraceae) from Turkey

The aerial parts of Tanacetum argyrophyllum (C. Koch) Tvzel. var. argyrophyllum and T. parthenium (L.) Schultz Bip. were hydro-distilled to produce the oils in the yields of 0.78% (v/w) and 0.43% (v/w), respectively. The oils were analysed by GC and GC/MS. Twenty-two and twenty-three components were identified representing 94.2% and 90.1% of the oils, respectively. The main compounds of T. argyrophyllum were cis-thujone (69.9%), transthujone (5.6%) and 1,8-cineole (3.2%), whereas camphor (56.9%), camphene (12.7%) and p-cymene (5.2%) were the major constituents of T. parthenium. (c) 2005 Published by Elsevier Ltd

Antioxidative activity of the essential oils of Thymus sipyleus subsp sipyleus var. sipyleus and Thymus sipyleus subsp sipyleus var. rosulans

The aim of present study was to compare the antioxidant potential of two Thymus species on the basis of the chemical compositions of oils obtained by hydrodistillation. In the case of Thymus sipyleus subsp. sipyleus var. sipyleus, 71 compounds were identified representing the 92.5% of the total oil. The major constituents of the oil were described as borneol (11.2%), alpha-muurolol (9.2%), (3-caryophyllene (7.6%), geranial (7.3%) and neral (5.4%). On the other hand, 47 compounds were identified representing 98.7% of the oil of Thymus sipyleus subsp. sipyleus var. rosulans. This oil is characterised by the high monoterpene fraction (94.0%) and especially by the presence of the phenolic carvacrol (58.1%), thymol (20.5%) and their precursors p-cymene (4.1%) and gamma-terpinene (4.4%). The oils were also subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene/linoleic acid assays. In the first case, the free radical scavenging activity of the essential oil of T. sipyleus subsp. sipyleus var. rosulans was superior to var. sipyleus oil (IC50 = 220 +/- 0.5 and 2670 +/- 0.5 mug/ml, respectively). In the case of linoleic acid system, oxidation of linoleic acid was effectively inhibited by T. sipyleus subsp. sipyleus var. rosulans (92.0%), while the var. sipyleus oil had no activity. In the latter case, the linoleic acid inhibition rate of var. rosulans oil is close to the synthetic antioxidant BHT (96.0%). (C) 2004 Elsevier Ltd. All rights reserved