03474nas a2200205   4500008004100000245011400041210006900155260017700224300001400401490000700415520263600422653001903058653001303077653002303090653001203113653001303125100001603138700001703154856009703171       2001                        eng d00aEssential oils enhanced by ultra-high carbon dioxide levels from Lamiaceae species grown in vitro and in vivo0 aEssential oils enhanced by ultrahigh carbon dioxide levels from   aAffiliation: U.S. Department of Agriculture, Agricultural Research Service, Natl. Ctr. Agric. Utiliz. Res., 1815 N. University St., Peoria, IL 61604, United Statesc2001///  a361 - 3680 v203 aThe growth (fresh weight), morphogenesis (leaves, roots and shoots) and essential oil composition of mint (Mentha sp. L.) and thyme (Thymus vulgaris L.) plants were determined after 8 weeks under 350, 1,500, 3,000, 10,000 and 30,000 μmol mol-1 CO2. Plants were grown in vitro on basal medium (BM) consisting of Murashige and Skoog salts and 0.8% agar that contained either 0 or 3% sucrose under a 16-h (day)/8-h (night) photoperiod at a light intensity of 180 μmol s-1 m-2 or in soil in a greenhouse under conditions of natural sunlight. Ultra-high CO2 levels (i.e. ≥3,000 μmol mol-1 CO2) substantially increased fresh weights, leaves, shoots and roots for all plants compared to plants grown under ambient air (350 μmol mol-1 CO2) both in vivo and in vitro. For both species, 10,000 μmol mol-1 CO2 was the optimum concentration to obtain the largest growth and morphogenesis responses under in vitro conditions, while the 3,000- to 10,000-μmol mol-1 CO2 range provided the largest yields for soil-grown plants. Essential oil composition (i.e. monoterpenes, piperitonone oxide and limonene from mint and aromatic phenol and thymol from thyme) from the shoot portion of plants grown at all CO2 levels was analyzed in CH2Cl2 extracts via gas chromatography. Higher levels of secondary compounds occurred in vitro when cultures were grown under ultra-high CO2 levels than in ambient air. The concentration of thymol, a major secondary compound in thyme plants grown on BM containing sucrose, was 317-fold higher at 10,000 μmol mol-1 CO2 than in plants grown under ambient air conditions with the same BM. The levels of secondary compound in in-vitro-grown plantlets exposed to ultra-high CO2 concentrations exceeded those occurring in plants grown in the greenhouse under the same CO2 levels. Substantially higher levels of secondary compound occurred in plants under ultra-high CO2 levels on BM containing sucrose than on BM lacking sucrose or in soil. Thymol levels in thyme plants grown on BM containing sucrose were 3.9-fold higher at 10,000 μmol mol-1 CO2 than in shoots grown on BM without sucrose under the same CO2 levels. High positive correlations occurred between thymol concentrations and CO2 levels, fresh weights, shoots, roots and leaves when thyme shoots were grown on BM with sucrose. High positive correlations for thyme shoots grown on BM without sucrose only occurred between thymol concentrations and CO2 levels, fresh weights, shoots and leaves. No positive correlations between thymol concentrations and CO2 levels or any growth or morphogenesis responses occurred for thyme shoots when grown in soil.10aCO2 enrichment10alimonene10aPiperitenone oxide10aRooting10aShooting1 aTisserat, B1 aVaughn, S, F  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0034931446&partnerID=40&rel=R6.5.001760nas a2200169   4500008004100000020001400041245006600055210006600121260001200187300001400199490001100213520115600224100001501380700001501395700001801410856016201428       2001                        eng d  a0105-187300aOccupational airborne contact dermatitis caused by thyme dust0 aOccupational airborne contact dermatitis caused by thyme dust  c2001///  a235 - 2390 v44; 443 aThe aim of the study was to assess occupational hazards to the farmer's skin associated with processing thyme (Thymus vulgaris L.). 46 farmers were studied during the threshing of dried thyme. They were questioned about work-related skin problems and examined before and after work. In all persons, serum thyme-specific IgE was measured. Skin prick tests, the Ouchterlony test and the migration inhibition test were carried out with allergens of airborne bacteria and fungi present in the working environment. Of the 46 farmers studied, 4 showed skin symptoms after 5-30 min of exposure to thyme dust. Thyme-specific IgE was found in 1 person with work-related symptoms, but also in 2 asymptomatic farmers. Therefore, the importance of IgE seems to be questionable in eczema related to thyme dust. Skin and blood tests with microbial allergens also showed no significant differences between the symptomatic and asymptomatic farmers. To our knowledge, this is the 1st description of occupational airborne contact dermatitis caused by thyme dust. The etiology of thyme-related skin symptoms remains obscure, although an irritant mechanism seems probable1 aSpiewak, R1 aSkorska, C1 aDutkiewicz, J  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=5&SID=b8599c660c0d7abb640bacacd8dd54da&MusePath=/ids70/view_record.php01876nas a2200229   4500008004100000245010300041210006900144260013900213300001400352490000700366520101900373653002401392653001801416653001301434653001401447653001301461653001201474653001101486653004001497100001201537856009701549       2001                        eng d00aVolatile oil variability in Thymus serpylloides ssp. gadorensis growing wild in Southeastern spain0 aVolatile oil variability in Thymus serpylloides ssp gadorensis g  aAffiliation: Geology Department, Fac. of Math. and Natural Sciences, Bergen University, Allégaten 41, 5007-Bergen, Norwayc2001/02//  a189 - 1980 v293 aVolatile oils from single plants of Thymus serpylloides ssp. gadorensis were collected from Southeastern Spain and studied to check for chemical variability using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Many of the samples showed a phenolic chemotype, while another important group had significant levels of linalool. Geraniol, myrcene, caryophyllene oxide, terpinen-4-o1 and 1,8-cineole were commonly present. Principal Component Analysis (PCA) and Cluster Analysis (CA) of this chemical variability separated two groups of plants characterized by either phenols or linalool, and an isolated third type with geraniol. A few samples were found to have both phenolic and non-phenolic compounds in high quantities, thus showing a mixed chemotype. Multidimensional scaling analysis (MDS) of the percentage concentration for each component of the essential oil showed that thymol, linalool, 1,8-cineole, borneol and geraniol have clear divergent vectors. © 2001 Elsevier Science Ltd.10acaryophyllene oxide10aEssential oil10aGeraniol10aLamiaceae10aLinalool10aMyrcene10aThymol10aThymus serpylloides ssp. gadorensis1 aSaez, F  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0035177231&partnerID=40&rel=R6.5.002339nas a2200337   4500008004100000245012500041210006900166260001400235300001400249490000700263520112500270653002601395653001201421653003001433653001801463653002401481653003601505653001901541653001301560653001001573653001401583653002201597653001301619653002501632653002001657653001201677100001901689700001701708700001601725856026001741       2001                        eng d00aA new histochemical method for localization of the site of monoterpene phenol accumulation in plant secretory structures0 anew histochemical method for localization of the site of monoter  c2001/10//  a521 - 5250 v883 aA new method is reported for the histochemical localization of monoterpene phenols in essential oil secretory structures. The method was adapted from a spot test originally devised for in vitro detection of phenolic compounds in organic analyses. Plant subjects were the Lamiaceae species Thymus vulgaris L., Oreganum vulgare L. and Mentha x piperha L., which accumulate essential oil in glandular trichomes. A reagent consisting of 4-nitrosophenol in cone. H2SO4 was applied to sample leaves of each species. A positive test for phenol was indicated by the production of coloured indophenols. Using this method, monoterpene phenols were identified in the trichomes of T. vulgaris (thymol) and O. vulgare (carvacrol), indicated by colour changes to red and green respectively. No phenol was detected in trichomes of M. x piperita. Results were confirmed by GC-MS analysis of leaf volatile extracts from each species, and In vitro tests with thymol and carvacrol. The method could be used in field surveys for rapid identification of potential medicinal plants and bioactive compounds. (C) 2001 Annals of Botany, Company.10aaromatic monoterpenes10ad u c t10adeveloped for qualitative10aEssential oil10aglandular trichomes10ahistochemical methods have been10ahistochemistry10ai n t ro10ai o n10aLamiaceae10amentha x piperita10aoreganum10asecretory structures10aThymus vulgaris10avulgare1 aGersbach, P.V.1 aWyllie, S.G.1 aSarafis, V.  uhttp://aob.oxfordjournals.org/cgi/doi/10.1006/anbo.2001.1480http://muse.lib.auth.gr:9797/org/oxfordjournals/?MuseHost=aob.oxfordjournals.org&MuseFirst=1&maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&fulltext=(thymus+AND+(labiatae+OR+lamiaceae))&searchid=1&FIR02120nas a2200157   4500008004100000020001400041245016000055210006900215260001200284300001400296490001100310520143900321100002401760700001601784856016201800       2001                        eng d  a0021-856100aAcute, sublethal, antifeedant, and synergistic effects of monoterpenoid essential oil compounds on the tobacco cutworm, Spodoptera litura (Lep., Noctuidae)0 aAcute sublethal antifeedant and synergistic effects of monoterpe  c2001///  a715 - 7200 v49; 493 aMonoterpenoids (terpenes and biogenically related phenols) commonly found in plant essential oils were tested for acute toxicity via topical application to tobacco cutworms (Spodoptera litura Fab.). The most toxic among 10 such compounds was thymol (LD(50) = 25.4 microg/larva) from garden thyme, Thymus vulgaris. The compounds were then tested for sublethal effects, specifically inhibition of larval growth after topical application of low doses. Among 6 compounds tested, an LD(10) dose reduced growth by 20% on average 3 days after administration. Feeding deterrence was determined using a cabbage leaf disk choice test. The most deterrent compound was thymol, with a DC(50) of 85.6 microg/cm(2) leaf disk area. Because minor constituents in complex essential oils have been suggested to act as synergists, binary mixtures of the compounds were tested for synergy vis à vis acute toxicity and feeding deterrence. trans-Anethole acted synergistically with thymol, citronellal, and alpha-terpineol, in terms of both acute toxicity and feeding deterrence. On the basis of these findings, several complex mixtures were developed and tested as leads for effective control agents. Candidate mixtures demonstrated good synergistic effects. The observed LD(50) of mixture 3 was 40.6 microg/larvae compared to an expected value of 74.6 microg/larvae. The result of this research is a proprietary product suitable for commercial production1 aHummelbrunner, L, A1 aIsman, M, B  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=6&SID=b8599c660c0d7abb640bacacd8dd54da&MusePath=/ids70/view_record.php02181nas a2200241   4500008004100000245012800041210007000169260013000239300001400369490000700383520126200390653001901652653000701671653001001678653001401688653004901702100002101751700001701772700001901789700001801808700001601826856009701842       2001                        eng d00aEssential oil composition of Thymus lotocephallus G. López & R. Morales, collected during flowering and vegetative phases0 aEssential oil composition of Thymus lotocephallus G López R Mor  aAffiliation: Centro de Biotecnologia Vegetal, Dep. de Biologia Vegetal, FCL, Campo Grande, 1749-016 Lisbon, Portugalc2001///  a417 - 4210 v163 aThe aerial parts of Thymus lotocephalus were collected during the flowering and vegetative phases of the plant in the Algarve, Portugal. The oils were isolated by hydrodistillation and distillation-extraction and analysed by GC and GC-MS. The oil isolated from the flowers was obtained in a yield of 0.9%, whereas those isolated from the leaves during flowering and vegetative phases showed lower yields, 0.7% and 0.2% (v/w), respectively. The oils isolated from both the flowers and the leaves were dominated by the oxygen-containing monoterpenes (57-64%). The monoterpene hydrocarbons (11-22%) and the oxygen-containing sesquiterpenes (7-14%) were the two other main fractions of these oils. 1,8-Cineole (10-19%), linalyl acetate (6-14%) and linalol (4-12%) were the main components of all the oils studied. Intermedeol (2-4%), beta -caryophyllene oxide (2-3%) and viridiflorol (1-3%) were the main components of the oxygen-containing sesquiterpene fraction. The diterpene abietatriene was present in trace amounts (<0.05%) in all the oils. Depending on the plant part studied and on the isolation procedure used, these oils can be characterized either by 1,8-cineole/linalol/linalyl acetate or 1,8-cineole type. Copyright (C) 2001 John Wiley & Sons, Ltd.10aEssential oils10aGC10aGC-MS10aLamiaceae10aThymus lotocephallus G. López & R. Morales1 aFigueiredo, A, C1 aMiguel, M, G1 aDuarte, A, M F1 aBarroso, J, G1 aPedro, L, G  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0035182964&partnerID=40&rel=R6.5.001721nas a2200241   4500008004100000245008100041210006900122260018200191300001400373490000700387520079700394653001401191653001601205653003001221653001301251653003201264653001101296653002401307100001901331700001601350700001601366856009701382       2001                        eng d00aIsolation of Thymus herba-barona volatiles by supercritical fluid extraction0 aIsolation of Thymus herbabarona volatiles by supercritical fluid  aAffiliation: Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria Monserrato, St. Prov. Sestu, km. 0.770 SS 5541, 090421 Cagliari, Italyc2001///  a240 - 2440 v133 aA volatile concentrate of Thymus herba-barona was isolated by supercritical CO2 extraction with a fractional separation technique. GC/MS analysis of the various fractions obtained at different extraction times and fractionation conditions allowed the identification of the best operating conditions to isolate the volatile extract. A good extraction performance was obtained operating at 90 bar and 50 degreesC for 300 min. The optimum fractionation was achieved by operating at 90 bar and -10 degreesC in the first separator and at 15 bar and 15 degreesC in the second one. The influence of extraction pressure and of extraction time on the extract composition were also evaluated. A comparison between a hydrodistilled oil of Thymus herba-barona and the supercritical extract is also given.10aCarvacrol10aComposition10aEssential oil composition10aLabiatae10aSupercritical fluid extract10aThymol10aThymus herba-barona1 aDe Gioannis, B1 aMarongiu, B1 aPorcedda, S  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0034876606&partnerID=40&rel=R6.5.002019nas a2200265   4500008004100000245009900041210006900140260010300209300001400312490000700326520110000333653001401433653001801447653002201465653001901487653001301506653003501519653001101554653002101565653001701586100002101603700001401624700001801638856009701656       2001                        eng d00aExtraction of thyme oil: Comparison between hydrodistillation and supercritical CO2 extraction0 aExtraction of thyme oil Comparison between hydrodistillation and  aAffiliation: Department of Chemical Engineering, Faculty of Technology, Skopje, Macedoniac2001///  a305 - 3100 v513 aSupercritical fluid extraction (SFE) with carbon dioxide and hydrodistillation (HD) were compared as methods to isolate essential oil from thyme herb (Thymus serpyllum, L.). The SFE extraction was performed in a semibatch apparatus and the rate of extraction was found dependent on the extraction pressure and temperature and on the amount of carbon dioxide passed through the extractor. The most suitable conditions for the extraction were 11 MPa and 50°C. The compounds extracted by both SFE and HD were identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The difference in the aroma of the products was quite noticeable and can be attributed to qualitative and quantitative differences in the extracts and hydrodistillates. Predominance of aromatic alcohols carvacrol and thymol and their biosynthetic precursors p-cymene and γ-terpinene was revealed in both SFE extracts and HD oil. The SFE extracts also contained water and cuticular waxes; longer extraction times and higher pressures resulted in a higher percentage of water and waxes in the extract.10aCarvacrol10aEssential oil10aHydrodistillation10aL. (Lamiaceae)10aP-cymene10aSupercritical fluid extraction10aThymol10aThymus serpyllum10aγ-terpinene1 aAleksovski, S, A1 aSovova, H1 aPoposka, F, A  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0035703173&partnerID=40&rel=R6.5.0