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1.
Food Chem ; 307: 125521, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655264

RESUMO

The essential oils and antioxidant activity of four Thymus species were evaluated under five light spectra (namely, red, blue, red-blue, white, and greenhouse condition). The highest essential oil yield (4.17%) was observed under red light in T. migricus, while the lowest (1.05%) was observed in T. carmanicus under greenhouse conditions. Light quality also led to difference in essential oil constituents. The highest thymol (66%) was found in T. migricus exposed to blue light, while the least (1.69%) was observed in T. kotschyanus grown under red-blue light. The LED treatments did not induce any significant effect on carvacrol of Thymus species in comparison to the greenhouse condition. Finally, the analysis of variance indicates that the effect of light varied with the studied species. T. migricus performed the highest antioxidant capacity (IC50 = 176.8 µg/mL) under blue light. Overall, essential oil components as well as antioxidants showed significant responses to light emitting diodes wavelengths.


Assuntos
Antioxidantes/metabolismo , Luz , Timol/metabolismo , Thymus (Planta)/química , Análise de Variância , Antioxidantes/química , Cromatografia Gasosa , Análise por Conglomerados , Efeito Estufa , Óleos Voláteis/química , Análise de Componente Principal , Timol/química , Thymus (Planta)/crescimento & desenvolvimento , Thymus (Planta)/metabolismo
2.
FEMS Microbiol Ecol ; 94(7)2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29771325

RESUMO

Inoculation of plants with beneficial plant growth-promoting bacteria (PGPB) emerges a valuable strategy for ecosystem recovery. However, drought conditions might compromise plant-microbe interactions especially in semiarid regions. This study highlights the effect of native PGPB after 1 year inoculation on autochthonous shrubs growth and rhizosphere microbial community composition and activity under drought stress conditions. We inoculated three plant species of semiarid Mediterranean zones, Thymus vulgaris, Santolina chamaecyparissus and Lavandula dentata with a Bacillus thuringiensis strain IAM 12077 and evaluated the impact on plant biomass, plant nutrient contents, arbuscular mycorrhiza fungi (AMF) colonization, soil rhizosphere microbial activity and both the bacterial and fungal communities. Inoculation with strain IAM 12077 improved the ability of all three plants species to uptake nutrients from the soil, promoted L. dentata shoot growth (>65.8%), and doubled the AMF root colonization of S. chamaecyparissus. Inoculation did not change the rhizosphere microbial community. Moreover, changes in rhizosphere microbial activity were mainly plant species-specific and strongly associated with plant nutrients. In conclusion, the strain IAM 12077 induced positive effects on plant growth and nutrient acquisition with no impact on the rhizosphere microbiome, indicating a rhizosphere microbial community resilient to native bacteria inoculation.


Assuntos
Asteraceae/crescimento & desenvolvimento , Bacillus thuringiensis/metabolismo , Fungos/metabolismo , Lavandula/microbiologia , Micorrizas/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Thymus (Planta)/crescimento & desenvolvimento , Asteraceae/microbiologia , Biomassa , Secas , Ecossistema , Lavandula/crescimento & desenvolvimento , Desenvolvimento Vegetal/fisiologia , Raízes de Plantas/microbiologia , Plantas/microbiologia , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/genética , Rizosfera , Solo , Microbiologia do Solo , Thymus (Planta)/microbiologia
3.
Pharm Biol ; 55(1): 1162-1170, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28222613

RESUMO

CONTEXT: Thymus alternans Klokov (Lamiaceae) is a neglected species of the genus Thymus (Sect. Serpyllum) endemic to Carpathian area, where it is used as a flavouring agent and for medicinal purposes. OBJECTIVE: The aim of the work was to identify antiproliferative constituents from the flowering aerial parts of this plant. MATERIALS AND METHODS: Thymus alternans extracts were analyzed by HPLC-MSn and subjected to extensive chromatographic separations. The isolated compounds (phenolics and triterpenes) were structurally elucidated by MS and 1D and 2D NMR experiments. Essential oil (EO) composition was determined by GC-FID and GC-MS. Six purified triterpenes and EO were assayed for in vitro antiproliferative activity against a panel of human cancer cells, namely, breast (MDA-MB 231), colon (HCT-15 and HCT116), lung (U1810), pancreatic (BxPC3), melanoma (A375) and cervical carcinoma (A431) cells. RESULTS: The structures of the isolated compounds were achieved on the basis of H-NMR and MS experiments. Luteolin-4'-O-ß-d-glucopyranoside (P1), chrysoeriol-7-O-ß-d-glucopyranoside (P2), chrysoeriol-5-O-ß-d-glucopyranoside (P3), apigenin-7-O-ß-d-glucopyranoside (P4), rosmarinic acid (P5), rosmarinic acid-3'-O-ß-d-glucopyranoside (P6), caffeic acid-3-O-ß-d-glucopyranoside (P7), 3α-hydroxy-urs-12,15-diene (T1), α-amyrin (T2), ß-amyrin (T3), isoursenol (T4), epitaraxerol (T5), and oleanolic acid (T6). GC-MS analysis revealed that the EO of T. alternans was devoid of phenols and belonged to the nerolidol-chemotype, that is typical of the Sect. Serpyllum. The six purified triterpenes (T1-T6) were active with IC50 ranging from 0.5 to 5 µM being comparable or better than those of reference compounds betulinic acid and cisplatin. The EO exhibited significant effects on A375, MDA-MB 231 and HCT116 cell lines with IC50 in the range of 5-8 µg/mL. CONCLUSION: The reported results suggest that T. alternans can be considered as a good source of phytoconstituents with possible importance in the pharmaceutical field.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Óleos Voláteis/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Óleos Vegetais/farmacologia , Thymus (Planta)/química , Antineoplásicos Fitogênicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cisplatino/farmacologia , Relação Dose-Resposta a Droga , Cromatografia Gasosa-Espectrometria de Massas , Células HCT116 , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Neoplasias/patologia , Óleos Voláteis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Fitoterapia , Componentes Aéreos da Planta , Extratos Vegetais/isolamento & purificação , Óleos Vegetais/isolamento & purificação , Plantas Medicinais , Eslováquia , Thymus (Planta)/crescimento & desenvolvimento , Triterpenos/farmacologia
4.
Anal Biochem ; 527: 49-62, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28209457

RESUMO

Thyme as a perennial herb has been recognized globally for its antimicrobial, antiseptic and spasmolytic effects. In this investigation, we have used non-targeted metabolite and volatile profiling combined with the morpho-physiological parameters in order to understand the responses at the metabolite and physiological level in drought sensitive and tolerant thyme plant populations. The results at the metabolic level identified the significantly affected metabolites. Significant metabolites belonging to different chemical classes consisting amino acids, carbohydrates, organic acids and lipids have been compared in tolerant and sensitive plants. These compounds may take a role through mechanisms including osmotic adjustment, ROS scavenging, cellular components protection and membrane lipid changes, hormone inductions in which the key metabolites were proline, betain, mannitol, sorbitol, ascorbate, jasmonate, unsaturated fatty acids and tocopherol. Regarding with volatile profiling, sensitive plants showed an increased-then-decreased trend at major terpenes apart from alpha-cubebene and germacrene-D. In contrast, tolerant populations had unchanged terpenes during the water stress period with an elevation at last day. These results suggesting that the two populations are employing different strategies. The combination of metabolite profiling and physiological parameters assisted to understand precisely the mechanisms of plant response at volatile metabolome level.


Assuntos
Adaptação Fisiológica , Secas , Metaboloma , Folhas de Planta/metabolismo , Thymus (Planta)/metabolismo , Aminoácidos/biossíntese , Aminoácidos/isolamento & purificação , Carboidratos/biossíntese , Carboidratos/isolamento & purificação , Ácidos Carboxílicos/isolamento & purificação , Ácidos Carboxílicos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Lipídeos/biossíntese , Lipídeos/isolamento & purificação , Metabolômica , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Análise de Componente Principal , Estresse Fisiológico , Terpenos/isolamento & purificação , Terpenos/metabolismo , Thymus (Planta)/química , Thymus (Planta)/crescimento & desenvolvimento
5.
Res Microbiol ; 168(3): 276-282, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27884782

RESUMO

We examined whether the microbiota of two related aromatic thyme species, Thymus vulgaris and Thymus citriodorus, differs in relation to the composition of the respective essential oil (EO). A total of 576 bacterial isolates were obtained from three districts (leaves, roots and rhizospheric soil). They were taxonomically characterized and inspected for tolerance to the EO from the two thyme species. A district-related taxonomic pattern was found. In particular, high taxonomic diversity among the isolates from leaves was detected. Moreover, data obtained revealed a differential pattern of resistance of the isolates to EOs extracted from T. vulgaris and T. citriodorus, which was interpreted in terms of differing chemical composition of the EO of their respective host plants. In conclusion, we suggest that bacterial colonization of leaves in Thymus spp. is influenced by the EO present in leaf glandular tissue as one of the selective forces shaping endophytic community composition.


Assuntos
Microbiota/fisiologia , Óleos Voláteis/metabolismo , Folhas de Planta/microbiologia , Óleos Vegetais/metabolismo , Thymus (Planta)/química , Thymus (Planta)/microbiologia , Adaptação Fisiológica , Carga Bacteriana/efeitos dos fármacos , Endófitos/classificação , Endófitos/efeitos dos fármacos , Endófitos/genética , Endófitos/isolamento & purificação , Microbiota/efeitos dos fármacos , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Folhas de Planta/química , Óleos Vegetais/isolamento & purificação , Óleos Vegetais/farmacologia , Raízes de Plantas/microbiologia , Solo , Thymus (Planta)/crescimento & desenvolvimento
6.
Phytochemistry ; 128: 20-6, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27174744

RESUMO

The effects of meteorological conditions (temperature, rainfall, photosynthetically active solar radiation (PAR) and sunshine duration) and plant growth stages on the quantitative composition of a secondary metabolite - essential oil and its main compounds, in the carvacrol chemotype of Thymus pulegioides L. (Lamiaceae) cultivated in open ground were studied under the same micro-edaphoclimatic environmental conditions for six years. The essential oil was isolated by hydrodistillation, the analysis of monoterpenic phenol carvacrol and the biogenetic precursors (monoterpene hydrocarbons p-cymene and γ-terpinene) were carried out annually using GC-FID and GC-MS. In the carvacrol chemotype investigated in this study, the yield of essential oil varied from 0.72% to 0.98% (CV = 12%) at full flowering stage. Regression analysis showed a significant negative relationship between the amount of essential oil and both temperature and rainfall during T. pulegioides flowering (July) and the period from April (beginning of vegetation) to July, but a strong positive relationship with photosynthetically active solar radiation during April-July (beta = 0.658, p < 0.05). The percentage of carvacrol, p-cymene and γ-terpinene ranged between 16.88 and 29.29% (CV = 18%), 5.54-11.33% (CV = 23%) and 20.60-24.43% (CV = 6%) respectively. Regression analysis showed the significant positive relationship between the percentage of carvacrol and sunshine duration at the flowering stage (in July) (beta = 0.699, p < 0.05); while the negative relationship was established between the percentages of precursors of carvacrol and photosynthetically active solar radiation and sunshine duration. The accumulation of p-cymene, the percentage of which varied most strongly from all investigated chemical compounds, showed significant positive relationships with temperature and rainfall during the period April-July and temperature in July (beta = 0.617, beta = 0.439 and beta = 0.429 respectively, p < 0.05). The analysis of plant growth stages showed that the highest amount of essential oil in carvacrol chemotype of T. pulegioides accumulated at ripening/seed maturity stage. The percentage of carvacrol increased gradually from the stem elongation to the post-flowering/seed maturity stage, overtaking the full flowering stage by 22%. The highest carvacrol content in the T. pulegioides carvacrol chemotype coincided with the highest oil yield during the fruiting stage. The amount of essential oil was also measured at the second full flowering stage, because after cutting the aerial part of the plant at the full flowering stage T. pulegioides often bloom for a second time: the carvacrol chemotype accumulated by 21% lower yield of essential oil at this stage compared to the first flowering, however, only traces of carvacrol and its precursors were found at the second full flowering stage.


Assuntos
Monoterpenos/análise , Thymus (Planta)/química , Meio Ambiente , Cromatografia Gasosa-Espectrometria de Massas , Lamiaceae/química , Óleos Voláteis/química , Desenvolvimento Vegetal/efeitos dos fármacos , Caules de Planta/química , Sementes/química , Thymus (Planta)/crescimento & desenvolvimento
7.
Acta Biol Hung ; 67(1): 64-74, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26960357

RESUMO

A pot experiment was carried out with lemon balm (Melissa officinalis L.) and thyme (Thymus vulgaris L.). Different water supply was applied: 25%, 40% and 70% saturation of soil water capacity (SWC). Morphological traits, biomass and phenolic type active ingredients were investigated. Among the two species, main differences were registered in biomass and TPC. Lower SWC resulted in reduced biomass production of lemon balm, while the applied stress treatments did not effect the biomass of thyme. In lemon balm, highest TPC contents were measured in control plants both in shoots and roots but in thyme, the shoots showed a significantly increased TPC at the 25% SWC conditions. Neither the content of total flavonoids nor that of the rosmarinic acid was affected by the treatments. The antioxidant capacity proved to be in tight connection with the TPC in both species (r = 0.766-0.883). The rosmarinic acid content of lemon balm plants contributed to the antioxidant capacity, as well (r = 0.679-0.869).


Assuntos
Cinamatos/metabolismo , Depsídeos/metabolismo , Flavonoides/metabolismo , Melissa/metabolismo , Polifenóis/metabolismo , Thymus (Planta)/metabolismo , Antioxidantes/metabolismo , Biomassa , Melissa/crescimento & desenvolvimento , Thymus (Planta)/crescimento & desenvolvimento
8.
Food Chem ; 173: 339-47, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466031

RESUMO

In traditional medicine, plants have been used since ancient times for the prevention and/or protection against infectious diseases. In recent years, the use of herbal medicines and food supplements containing botanical ingredients, as alternative therapy for infectious diseases, has been intensified due to their high content of antimicrobial agents such as polyphenols, i.e. flavonoids, tannins, and alkaloids. Plants from the genus Thymus are important medicinal herbs, which are known to contain antimicrobial agents, and are rich in different active substances such as thymol, carvacrol, p-cymene and terpinene. In this review, we summarise the available literature data about the in vitro antibacterial effects of the main plants belonging to the genus Thymus. We also provide information about cultivation, chemical composition of the essential oils obtained from these plants, and their use for medicinal purposes.


Assuntos
Antibacterianos/farmacologia , Extratos Vegetais/farmacologia , Thymus (Planta)/química , Animais , Antibacterianos/química , Humanos , Extratos Vegetais/química , Thymus (Planta)/classificação , Thymus (Planta)/crescimento & desenvolvimento
9.
Oecologia ; 177(1): 133-46, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25348574

RESUMO

The canopy shade of the Retama species has been widely reported to ameliorate the environmental conditions in the understory, thus facilitating other species' establishment. The shading effect of the native-invasive leguminous shrub Retama monosperma (L.) Boiss on the endangered Thymus carnosus Boiss was analysed to determine a positive or negative net effect. Data was taken in all four seasons, representing contrasting light and water availability in a Mediterranean coastal dune ecosystem (SW Spain). The morphological and physiological status of sun-exposed T. carnosus plants growing in open areas versus shaded plants growing under R. monosperma were measured seasonally. Leaf mass area, leaf area index and pigment content showed typical sun-shade responses. In contrast, sun-exposed T. carnosus displayed higher stem water potential, transpiration rate and water use efficiency, both intrinsic and integrated, denoting low tolerance to the presence of R. monosperma. Five years after the measurements, canopy cover had decreased and mortality was higher in shaded plants, thus confirming the competitive effect of R. monosperma on T. carnosus. R. monosperma arises as a competitor for endangered T. carnosus communities, consequently reinforcing its invasive behaviour. This species-specific shrub study demonstrates that eventual beneficial effects of Retama canopy may be overridden by competition in the understory, particularly in the case of species well-adapted to high light and low water levels.


Assuntos
Ecossistema , Espécies em Perigo de Extinção , Fabaceae/crescimento & desenvolvimento , Espécies Introduzidas , Luz , Thymus (Planta)/crescimento & desenvolvimento , Água , Animais , Ecologia , Meio Ambiente , Região do Mediterrâneo , Folhas de Planta , Caules de Planta , Transpiração Vegetal , Estações do Ano , Espanha
10.
Cryo Letters ; 33(5): 363-75, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23224369

RESUMO

Thymus is an important genus of the Lamiaceae family, comprising more than 400 perennial aromatic thyme species, which are used extensively for medicinal and culinary purposes. The present study focused on the development of cryopreservation procedures for Thymus vulgaris and T. cariensis, the latter being an endemic and endangered species of Turkey. For cryopreservation of T. vulgaris shoot tips, PVS2-based one-step freezing methods, i.e., PVS2 vitrification, encapsulation-vitrification and droplet-vitrification, were compared. Cold hardening and sucrose preculture were also optimized before the cryopreservation trials. For T. cariensis, a droplet-vitrification method was applied to cold-hardened shoot tips, and after sucrose preculture. In all the methods tested, PVS2 was applied for up to 120 min. The best T. vulgaris cryopreservation was achieved with a droplet-vitrification method, that involved 2-weeks cold hardening of shoot cultures, 48 h preculture of shoot tips on MS medium supplemented with 0.25 M sucrose, and a 90 min PVS2 treatment in droplets. After direct immersion in LN, thawing and plating, 80% of shoot-tips recovered. Post-thaw recovery was significantly lower when the same procedure was applied to T. cariensis shoot tips; however also here 90 min PVS2 treatment produced the highest survival (25 percent) and recovery (25 percent) levels.


Assuntos
Criopreservação/métodos , Brotos de Planta/fisiologia , Thymus (Planta)/fisiologia , Vitrificação , Crioprotetores/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Sacarose/metabolismo , Thymus (Planta)/crescimento & desenvolvimento
11.
Cryo Letters ; 31(4): 301-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20818458

RESUMO

Vitrification and encapsulation-dehydration were tested for cryopreservation of Thymus moroderi Pau ex Martínez (Labiatae), an endemic plant from south-eastern Spain. For vitrification, shoot tips were loaded in a solution containing 0.4 M sucrose + 2 M glycerol for 20 min at room temperature, dehydrated in PVS2 solution for 0-105 min at 0 degree C, then immersed in liquid nitrogen (LN) for at least 1 day and rapidly rewarmed. The highest survival (71.4 percent) was obtained after 60 min PVS2 dehydration. Encapsulation-dehydration gave slightly lower results, with up to 50 percent explants survival. In the optimal protocol, donor plants were cold-hardened at 10 degree C for 5 weeks, excised shoot tips precultured for 48 h on MS medium with 0.08 M sucrose, encapsulated, pretreated in medium with 0.75 M sucrose for 19 h, desiccated to 22 percent moisture content (fresh weight basis), and immersed in LN. Vitrification thus appears more suitable than encapsulation-dehydration for cryopreservation of T. moroderi shoot tips.


Assuntos
Criopreservação/métodos , Dessecação , Brotos de Planta/crescimento & desenvolvimento , Thymus (Planta)/crescimento & desenvolvimento , Vitrificação , Adaptação Fisiológica , Crioprotetores/farmacologia , Brotos de Planta/fisiologia , Sacarose/farmacologia , Thymus (Planta)/fisiologia
12.
Cryo Letters ; 31(1): 14-23, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20309505

RESUMO

Thymus moroderi Pau ex Martinez (Labiatae) was successfully cryopreserved using the droplet vitrification method. After 20 min in loading solution at room temperature, shoot tips were dehydrated with PVS2 at 0 degree C for 30 min and immersed into LN. For thawing, shoot-tips were transferred into recovery solution for 15 min. A test of different recovery media revealed that the best results were obtained when the medium was supplement with 0.275 micromolar BA.


Assuntos
Criopreservação/métodos , Brotos de Planta/citologia , Brotos de Planta/crescimento & desenvolvimento , Thymus (Planta)/citologia , Thymus (Planta)/crescimento & desenvolvimento , Meios de Cultura , Liofilização/métodos , Temperatura Ambiente , Água
13.
Nat Prod Commun ; 5(12): 1985-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21299137

RESUMO

Thymus capitatus growing wild in Sardinia showed different essential oil composition if grown surrounding Cagliari than in north Sardinia. Here we verify the composition and antimicrobial activity of the oil to make it suitable for the cosmetic and confectionery industries. With the aim of improving the scent and the antimicrobical activity of T. capitatus essential oil, a hydroformylation reaction was carried out to transform the unsaturated components of the oil into the corresponding aldehydes. The essential oil of T. capitatus exhibited a significant antibacterial activity (MIC 0.125-0.5 mg/mL), and was also found effective on C. albicans (MIC 0.125 mg/mL). After hydroformylation, several new irregular terpenoid aldehydes were detected. The perfume of the new terpenic-like aldehydes is very agreeable and, therefore, the acceptability of the aroma is remarkably improved, but the antimicrobial activity was not increased.


Assuntos
Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Thymus (Planta)/química , Itália , Thymus (Planta)/crescimento & desenvolvimento
14.
J Agric Food Chem ; 57(14): 6392-5, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-19601670

RESUMO

In vitro shoots of thyme (Thymus vulgaris L.) were established, and the effects of the auxin indole-3-acetic (IAA) acid and the cytokinins benzyladenine (BA), zeatin (ZEA), and kinetin (KIN) at 1.0, 5.0, and 10.0 microM on rooting, biomass production, and volatile compounds production by these plants were investigated. The volatiles were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography. The highest biomass shoot growth was obtained with BA at 5.0 microM, while IAA at all concentrations tested achieved 100% rooting frequency. The three major compounds were gamma-terpinene (22.8-38.8%), p-cymene (13.8-27.9%), and thymol (6.5-29.0%). Quantitative changes of these compounds were observed in response to the effect of varying growth regulators concentrations in the culture medium. Growing Thymus vulgaris L. plants in media supplemented with IAA at 1.0 microM increased volatile compounds such as thymol by 315%. Nevertheless, the same major compounds were produced in all treatments and no qualitative changes were observed in the volatile profile of thyme plants.


Assuntos
Odorantes/análise , Reguladores de Crescimento de Planta/farmacologia , Thymus (Planta)/efeitos dos fármacos , Thymus (Planta)/crescimento & desenvolvimento , Cromatografia Gasosa , Citocininas/farmacologia , Ácidos Indolacéticos/farmacologia , Monoterpenos/análise , Timol/análise , Thymus (Planta)/química
15.
Curr Pharm Des ; 14(29): 3120-40, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19075695

RESUMO

Thymbra capitata and Thymus species are commonly known in Portugal as thyme and they are currently used as culinary herbs, as well as for ornamental, aromatizing and traditional medicinal purposes. The present work reports on the state of the art on the information available on the taxonomy, ethnobotany, cell and molecular biology of the Portuguese representatives of these genera and on the chemotaxonomy and antibacterial, antifungal and antioxidant activities of their essential oils and other volatile-containing extracts.


Assuntos
Antifúngicos , Antioxidantes , Óleos Voláteis , Óleos Vegetais , Thymus (Planta) , Animais , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Classificação , Etnobotânica , Humanos , Lamiaceae/química , Lamiaceae/classificação , Lamiaceae/crescimento & desenvolvimento , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Óleos Vegetais/química , Óleos Vegetais/isolamento & purificação , Óleos Vegetais/farmacologia , Portugal , Thymus (Planta)/química , Thymus (Planta)/crescimento & desenvolvimento
16.
Oecologia ; 141(3): 511-8, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15309611

RESUMO

Local modification of the soil environment by individual plants may affect the performance and composition of associated plant species. The aromatic plant Thymus vulgaris has the potential to modify the soil through leaching of water-soluble compounds from leaves and litter decomposition. In southern France, six different thyme chemotypes can be distinguished based on the dominant monoterpene in the essential oil, which is either phenolic or non-phenolic in structure. We examine how soils from within and away from thyme patches in sites dominated by either phenolic or non-phenolic chemotypes affect germination, growth and reproduction of the associated grass species Bromus erectus. To do so, we collected seeds of B. erectus from three phenolic and three non-phenolic sites. Seeds and seedlings were grown on soils from these sites in a reciprocal transplant type experiment in the glasshouse. Brome of non-phenolic origin performed significantly better on its home soil than on soil from a different non-phenolic or a phenolic site. This response to local chemotypes was only observed on soil collected directly underneath thyme plants and not on soil in the same site (<5 m away) but where no thyme plants were present. This is preliminary evidence that brome plants show an adaptive response to soil modifications mediated by the local thyme chemotypes. Reproductive effort was consistently higher in brome of phenolic origin than in brome of non-phenolic origin (on both thyme- and grass-soil), indicating that life-history variation may be related to environmental factors which also contribute to the spatial differentiation of thyme chemotypes. Moreover, we found that brome growing on thyme-soil in general was heavier than when growing on grass-soil, regardless of the origin of the brome plants. This is concordant with thyme-soil containing higher amounts of organic matter and nitrogen than grass-soil. Our results indicate that patterns of genetic differentiation and local adaptation may modify competitive interactions and possible facilitation effects in natural communities.


Assuntos
Bromus/química , Bromus/crescimento & desenvolvimento , Fenóis/análise , Thymus (Planta)/química , Thymus (Planta)/crescimento & desenvolvimento , Adaptação Fisiológica , Nitrogênio/metabolismo , Compostos Orgânicos/metabolismo , Dinâmica Populacional , Plântula/química , Sementes/química , Solo
17.
Mycorrhiza ; 14(1): 47-54, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14564560

RESUMO

A study was performed to establish whether colonisation with arbuscular mycorrhizal (AM) fungi is beneficial to wild thyme [ Thymus polytrichus A. Kerner ex Borbás ssp. britannicus (Ronn.) Kerguelen (Lamiaceae)] growing in the heavy-metal-contaminated soils along the River South Tyne, United Kingdom. T. polytrichus plants of the same genotype were grown under controlled conditions with and without Zn contamination, and differences between AM-colonised and -uncolonised plants in mean shoot and root growth (dry weight) and Zn concentration were assessed. When grown in the heavy-metal-contaminated, low-P soil from one of the South Tyne sites, AM-colonised plants grew significantly larger than uncolonised plants; however, there was no significant difference in growth between AM and non-AM plants grown in an artificial substrate with a larger available P concentration, with or without Zn contamination. Mycorrhizal colonisation increased tissue Zn concentrations during the experiments. It is concluded that AM fungi are beneficial, if not essential, to T. polytrichus growing in the low-nutrient soils along the River South Tyne, because of their role in enhancing plant uptake of P (and possibly other nutrients). There was no evidence from this study that the fungi reduce plant uptake of heavy metals at these sites, but rather increase Zn uptake. However, the resulting tissue metal concentrations do not appear to be large enough to be detrimental to plant growth.


Assuntos
Fungos/fisiologia , Micorrizas/fisiologia , Thymus (Planta)/crescimento & desenvolvimento , Thymus (Planta)/microbiologia , Inglaterra , Metais Pesados/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Brotos de Planta/crescimento & desenvolvimento , Solo , Poluentes do Solo/metabolismo , Zinco/metabolismo
18.
J Agric Food Chem ; 51(26): 7751-8, 2003 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-14664540

RESUMO

The influence of nitrogen fertilizers on the yield of crop, as well as on the production and composition of the essential oil and some other chemical characteristics of thyme, was investigated. Different levels of fertilizers (N = 0, 45, 90, and 135 kg x ha(-)(1)) were applied. It was found that fertilizers increase thyme crop, but differences in the yield of essential oil were not remarkable. However, the use of certain amounts of nitrogen fertilizers resulted in higher yields of essential oil obtainable from the cultivation area unit (dm(3) ha(-)(1)). Totally, 61 constituents were identified in thyme essential oil by capillary GC and GC-MS. Thymol was the dominating compound in the all analyzed oils (44.4-58.1%), followed by p-cymene (9.1-18.5%), gamma-terpinene (6.9-18.9%), and carvacrol (2.4-4.2%). Differences in the percentage of these and other compounds in thyme herb cultivated under different fertilization doses were not significant; very slight changes in the percentage composition were detected after drying. Some variations in the amount of individual constituents expressed in arbitrary units per kilogram of herb (which is almost equivalent to mg x kg(-)(1)) were observed. The highest amounts of sugars and sucrose, in particular, were determined in the second year of thyme cultivation. Differences in the content of dry soluble substances were not meaningful, and there was no effect of nitrogen fertilizers on this chemical characteristic. Some effect of fertilization on the content of vitamin C and carotenes was observed in the first year of thyme cultivation. It was determined that nitrogen fertilizers influence the amount of nitrates, which was highest in the second-year-first-harvest.


Assuntos
Fertilizantes , Nitrogênio/administração & dosagem , Thymus (Planta)/química , Thymus (Planta)/crescimento & desenvolvimento , Ácido Ascórbico/análise , Carboidratos/análise , Óleos Voláteis/análise , Óleos Vegetais/análise , Timol/análise
19.
J Agric Food Chem ; 51(18): 5420-7, 2003 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-12926892

RESUMO

Thymus hyemalis Lange (chemotype thymol) was cultivated as an experimental crop under different watering level conditions in order to achieve 80, 60, 40, and 20% of the local potential evapotranspiration (Eto). Two harvesting periods were considered, winter and spring. As a consequence of the great variability among plants, essential oil yield percentages did not show statistically significant differences among seasons and different levels of water supply. Capillary GC-MS analysis of the essential oils permitted the detection of 84 volatile components. Among them, 54 are described for the first time as volatile constituents of the chromatographic profile of this Thymus species. Winter harvesting showed high concentrations in thymol percentage (25.92 +/- 4.39), the 40% Eto watering level being the best with respect to obtaining the optimum quality of this essential oil. However, in spring this thyme species needs a greater water supply (80% Eto) to achieve the same amount of thymol in the essential oil (29.20 +/- 2.83). From this, it was concluded that winter harvesting could be used for the extraction of the essential oil, with a low level of water supply, whereas spring harvesting could be employed for collection of leaves as a food condiment.


Assuntos
Lamiaceae/química , Lamiaceae/crescimento & desenvolvimento , Óleos Voláteis/análise , Óleos Voláteis/química , Água , Cromatografia Gasosa-Espectrometria de Massas , Estações do Ano , Timol/análise , Thymus (Planta)/química , Thymus (Planta)/crescimento & desenvolvimento
20.
J Agric Food Chem ; 51(13): 3849-53, 2003 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-12797754

RESUMO

The chemical composition of essential oils from aerial parts of Thymus spinulosus Ten. (Lamiaceae) is reported. Four oils from plants growing in different environmental conditions were characterized by GC and GC-MS methods; the oils seem to indicate a new chemotype in the genus Thymus. Influences of soil and altitude characteristics on the essential oil composition are discussed. The oils showed antibacterial activity against Gram-positive (Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis, and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella typhimuium Ty2, and Pseudomonas aeruginosa) bacteria.


Assuntos
Antibacterianos/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Thymus (Planta)/química , Cromatografia Gasosa , Meio Ambiente , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Positivas/efeitos dos fármacos , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Estruturas Vegetais/química , Solo/química , Thymus (Planta)/crescimento & desenvolvimento
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