Thymus Kotschyanus Research Articles

Influence of some chemical compounds on germination and early seedling growth of two range species under allelopathic conditions

Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significantly decreased (P < 0.01) by increasing extract concentrations of Thymus kotschyanus allelopathic compounds in unprimed seed (control) compared with primed seeds. Seed priming enhanced germination percentage, germination speed and initial growth. Overall, the results of this study showed that the response of both species to pretreatment of seeds was positive. Therefore, pretreatments of seeds with the aforementioned chemical stimulators before planting can significantly reduce the negative effect of allelopathic compounds in Thymus kotschyanus during the germination stage and contribute to plant establishment by increasing germination speed and growth of embryos.

Biological activity of some plant essential oils against Varroa destructor (Acari: Varroidae), an ectoparasitic mite of Apis mellifera (Hymenoptera: Apidae)

This experiment was conducted to evaluate acaricidal activity of the essential oils of Thymus kotschyanus, Ferula assa-foetida and Eucalyptus camaldulensis against Varroa destructor under laboratory conditions. Moreover, fumigant toxicity of these oils was tested on Apis mellifera. After preliminary dose-setting experiments, mites and honey bees were exposed to different concentrations of the oil, with 10 h exposure time. Essential oil of T. kotschyanus appeared the most potent fumigant for V. destructor (LC(50) = 1.07, 95% confidence limit (CL) = 0.87-1.26 μl/l air), followed by E. camaldulensis (LC(50) = 1.74, 95% CL = 0.96-2.50 μl/l air). The lowest acaricidal activity (LC(50) = 2.46, 95% CL = 2.10-2.86 μl/l air) was attributed to essential oil of F. assa-foetida. Surprisingly, among the three oils tested, essential oil of T. kotschyanus had the lowest insecticidal activity against A. mellifera (LC(50) = 5.08, 95% CL = 4.54-5.06 μl/l air). These findings proved that essential oil of T. kotschyanus has potential of practical value for use as alternative acaricide in the management of varroa in apiaries.

Control of Penicillium expansum and Botrytis cinerea on pear with Thymus kotschyanus, Ocimum basilicum and Rosmarinus officinalis essential oils

The aim of this study was to test the possibility of the use of Thymus kotschyanus,Ocimum basilicum and Rosmarinus officinalis essential oils to reduce postharvest losses induced by Botrytis cinerea and Penicillium expansum in pear fruits. In this study, the antifungal activity of essential oils under in vitro condition were assayed by poison food medium method (0, 100, 200, 300, 400 and 500 μL/L) and under in vivo condition by spraying different essential oil concentrations (0, 100, 300 and 500 μL/L) on inoculated pear fruits. Results of the present study showed that T. kotschyanus had the highest antifungal activity under in vitro condition and completely inhibited fungal growth at concentrations above 200 μL/L. Results of in vivo studies showed that T. kotschyanus oil decreased the disease severity and number of infected pear fruits inoculated with B. cinerea and P. expansum. Measurement of quality sensors of pear fruits showed that essential oil treatment increased the taste of fruits. T. kotschyanus oil also reduced and in the contrast O. basilicum oil increased the firmness of oil-treated fruits. Results of this study showed that T. kotschyanus had good inhibitory effect on growth of phytopathogenic fungi and may be used as a new tool for preservation and extension of shelf-life of pear fruits. Key words: Essential oil, pear, Thymus kotschyanus, Ocimum basilicum, Rosmarinus officinalis, antifungal.

IMPROVING POSTHARVEST QUALITY OF TABLE GRAPE CV. “RISH BABA” USING THYMUS KOTSCHYANUS AND CARUM COPTICUM ESSENTIAL OILS

ABSTRACTThe antifungal activity of different concentrations of Thymus kotschyanus and Carum copticum essential oils (0, 100, 200, 300, 400 and 500 µL/L) on mycelial growth of Botrytis cinerea and Penicillium digitatum under in vitro condition were investigated. Also, the preservative property of various concentrations of these essential oils (0, 250 and 500 µL/L) to maintenance quality parameters of “Rish Baba” table grape were studied. Chemical compositions of the essential oils were also determined by gas chromatography–mass spectrometry analysis. Major compounds found in essential oils from T. kotschyanus and C. copticum were carvacrol (28.54%) and thymol (63.18%), respectively. The results of in vitro assay showed that T. kotschyanus and C. copticum essential oils in 300–500 µL/L concentration completely inhibited the mycelial growth of B. cinerea and P. digitatum. Also, at the end of the storage period, all the applied concentration of essential oils reduced disease severity compared to control fruit. The application of essential oil did not affect the berry shrinkage and rachis browning. However, essential oil treatment showed high preservative effect on weight loss, appearance, flavor, berry browning, total soluble solids (TSS), titrable acidity (TA) and TSS/TA of treated fruits. Therefore, essential oils may be used as an alternative for the synthetic chemicals for control of postharvest phytopathogenic fungi, and in turn to fulfill consumer requirements for more natural and healthy fruits.PRACTICAL APPLICATIONSPostharvest disease of perishable fruits such as table grape renders heavy losses during transit and storage. Use of chemical fungicides such as SO2 generator pads are basic means of controlling postharvest diseases of table grape. Public awareness about chemical residues in food and interest to use of organic crops intended search to find a new safe alternatives to synthetic fungicides. The main reason for examine the possibility use of essential oils are they plant origins, safe, no side‐effect and their acceptability for consumers. Consequently, recently the interest to use of essential oils to preserve of fruits and vegetables has increased. The goal of this research was to examine the possibility use of T. kotschyanus, C. copticum essential oils to maintain postharvest quality of table grapes.

Reversal of Resistance in MRSA Strains by Thymus kotschyanus Essential Oil

In this study the essential oil of Thymus kotschyanus Boiss. & Hohen, which is endemic of Iran, was investigated for its antibacterial activity and its combined effects with oxacillin or methicillin against several clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations of oxacillin, methicillin and essential oil against MRSA strains were determined by the micro-dilution method. Synergy testing of each antibiotic and essential oil against MRSA was performed by the checkerboard technique. The results indicated that T. kotschyanus essential oil had synergistic effect with oxacillin or methicillin against MRSA strains. The best synergistic effect obtained against MRSA5 and S. aureus ATCC 33591 which resulted in 32 times decrease in MIC values of oxacillin and methicillin. The synergistic activity showed that this non-antibiotic agent manifests a broad spectrum of activity against MRSA bacteria which might open a new therapeutic approach to combat drug-resistance in bacterial infections.

Thymus kotschyanus and Carum copticum essential oils as botanical preservatives for table grape.

In the present study, essential oils extracted from Thymus kotschyanus and Carum copticumhas been evaluated for efficacy in the control of postharvest fungal decay in Thompson seedless table grape. Results showed that the tested oils exhibited good inhibitory activity against fungal decay in oil-treated grapes. In addition, the essential did not show a negative impact on the sensory quality of the grape. The profile of the oil components showed that carvacrol (28.54%) and thymol (63.18%) were the main compounds available in T. kotschyanusand C. copticum respectively. Results of this research showed that the evaluated essential oils may be used as a preservative for reduction of postharvest losses. Key words: Essential oil, table grape, Thymus kotschyanus, Carum copticum, antifungal.

Allelopathic effects of Thymus kotschyanus on seed germination and initial growth of Bromus tomentellus and Trifolium repens

The allelopathic influence of aqueous extracts of Thymus kotschyanus on Bromus tomentellus and Trifolium repens germination (%), germination speed, and seedling growth (length, fresh and dry weight) was examined. It was noted that aqueous extracts had a considerable inhibitory effect on target plant germination, and the effect at 50%, 75%, and 100% concentration was found to be significantly higher than that at lower concentrations (5% and 25%) and control treatment (distilled water). Seedling length in addition to fresh and dry weights was also reduced significantly over control. The inhibitory effect was increased as the extract concentration was increased. B. tomentellus showed a higher sensitivity against T. kotschyanus in allelopathic effects compared to T. repens, which indicates that B. tomentellus planted in rangelands with leaf litter of T. kotschyanus will be adversely affected in terms of its germination, growth, and ultimately low forage production.

Composition of essential oils of leaves, stems, and roots of Thymus kotschyanus VAR. pseuderiophorus growing wild in Iran

98.4%, 20 constituents representing 99.3%, and 24 compound representing 98.3% of the leaf, stem, and root oils, respectively. As can be seen from the above information, the oils from leaves, stems, and roots of T. kotschyanus var. pseuderiophorus Rech. f.p.p are rich in oxygenated monoterpenes (79.2%, 84.6%, 80.7%) and contain small amount of monoterpene hydrocarbons and very few sesquiterpenoids. Comparison of these results with previous investigations on oils of the genus Thymus showed that they were also dominated by monoterpenes. The dominant compound in the oil of T. serrulatus 3, T. carnosus 4, T. transcaspicus 5, T. vulgaris 6, T. daenensis 7, T. fallax 8 and T. eriocalyx 9 was thymol (49.0%, 36.1%, 56.4%, 39.1%, 73.9%, 65.9%, and 43.1%, respectively). The oil of T. serpyllum consisted mainly of -terpinene (21.9% and 22.7%), p-cymene (21.1% and 20.7%), and thymol (18.7% and 18.7%) before flowering and at the full flowering stage, respectively 10. In the essential oil of T. citriodorus cultivated in Iran, geraniol (54.4%), geranial (13.9%), and neral (10.1%) were the main constituents 11. The major compounds in T. persicus oil were found to be carvacrol (39.0% and 27.1%), geraniol (15.7% and 9.4%), p-cymene (7.5% and 10.2%), and thymol (6.5% and 11.9%) before flowering and at the full flowering stage, respectively 12. In another study, pulegone (18.7%), isomenthone (17.8%), and thymol (14.9%) were the main constituents in T. kotschyanus oil, and the main compounds in the T. pubescens oil were found to be carvacrol (32.1%), thymol (19.1%), and -terpineol (14.6%) 13. Seventy-eight components were identified comprising 88.0% and 91.3% of the total components in the oils, respectively. 1,8-Cineole (21.5%) was the dominant compound in T. haussknechtii oil and thymol (47.5%) was the main component in the oil of T. kotschyanus var. kotschyanus 16.

Determination of the carvacrol concentration in the essential oil of Thymus kotschyanus

Determination of the carvacrol concentration in the essential oil of Thymus kotschyanus

Anti- Candida albicans activity of some Iranian plants used in traditional medicine

Summary Objective To screen anti- Candida albicans activity of the essential oils of 16 Iranian medicinal plants. Materials and methods Anti- C. albicans effect of plant oils, amphotericin B, nystatin and ketoconazole were determined by disc diffusion and broth macrodilution methods. Results Fourteen (87%) out of the 16 plants were found to be active. These oils confirmed the existence of a significant activity against C. albicans tested with minimal inhibitory concentration (MIC) values ranging from 150 to 2300 μg/ml using broth macrodilution method and the growth inhibition zone ranging from 16 to 55 mm using disc diffusion method. The essential oils of Zataria multiflora, Thymus kotschyanus, Cuminum cyminum and Plargonium graveolens showed significant activity against C. albicans ( P Conclusion The oils that showed strong anti- Candida activity are worth of further investigations in order to identify the active compounds and their clinical applications for the treatment of candidiasis.

Isolation and identification of antibacterial compounds from Thymus kotschyanus aerial parts and Dianthus caryophyllus flower buds

The aerial parts of Thymus kotschyanus Boiss. and Hohen. (Lamiaceae) and flower buds of Dianthus caryophyllus L. (Caryophyllaceae) have been traditionally implemented in the treatment of wounds, throat and gum infections and gastro-intestinal disorder by the indigenous people of northern Iraq, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from both plants were isolated and characterized, and the biological activity of each compound was assessed individually and combined. Compounds were isolated and characterized from the extracted essential oils of both plants using different spectral techniques: TLC, FTIR spectra and HPLC. The minimum inhibitory concentrations MIC values for the compounds were assessed individually and combined based on a microdilution and the checkerboard method in 96 multi-well microtiter plates. Two known compounds were isolated from the essential oils of both plants and were identified as thymol and eugenol. The isolated compounds were investigated for their single and combined antibacterial activities against seven selected pathogenic bacteria; Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Thymol MIC values ranged from 15.6 to 250.0 microg/ml and B. cereus was found to be the most sensitive pathogen with a MIC value of 15.6 microg/ml. Eugenol achieved stronger MIC values against most tested pathogens and the best MIC value (15.6 microg/ml) was observed against B. cereus, L. monocytogenes and K. pneumoniae whereas, S. aureus, P. mirabilis and E. coli were inhibited with a MIC value of 31.2 microg/ml. Combination results had antibacterial enhancement against most pathogens and the best synergistic result was seen against P. mirabilis and E. coli. The isolation of two antibacterial compounds from Thymus kotschyanus aerial parts and Dianthus caryophyllus flower buds validates the use of these species in the treatment of throat and gum infections, wound-healing and gastro-intestinal disorder.

Effects of Thymus kotschyanus var. glabrescens Boiss. extract on mitomycin-C induced chromosomal aberrations and sister chromatid exchanges in human lymphocytes

In this investigation, clastogenic effects of Thymus kotschyanus var. glabrescens Boiss. extract (TE) and anticlastogenic effects of this extract against Mitomycin C (MMC) induced chromosome damage have been evaluated in human peripheral blood lymphocytes in vitro. Two series of experiments were conducted. In the first, only 10(-5), 10(-4), 10(-3) and 10(-2) mul ml(-1) concentrations of TE were used for 48 h to detect potential clastogenicity. In the second, MMC (0.38 mug ml(-1)) plus 10(-5), 10(-4), 10(-3) and 10(-2) mul ml(-1) concentrations of TE were used for 48 h to determine anticlastogenic effects. TE did not increase sister chromatid exchanges (SCEs) (except 10(-2) mul ml concentration) and chromosome aberrations (CAs) significantly compared with negative and solvent controls. However, it decreased the frequency of MMC induced chromosome aberrations. Decreasing was significant at 10(-4), 10(-3) and 10(-2) mul ml(-1) concentrations. On the other hand, TE significantly increased MMC-induced SCEs for all treatment groups compared with positive control.

Essential Oil Composition of Thymus kotschyanus and Thymus pubescens from Iran

The essential oils of the aerial parts of Thymus kotschyanus Boiss. et Hohen. and T. pubescens Boiss. et Kotschy ex Celak. (Labiatae) collected during the full flowering period from the suburb of Behshar (north of Iran) were isolated by hydrodistillation and analyzed by GC and GC/MS. The major components of T. kotschyanus oil were pulegone (18.7%), isomenthone (17.8%), thymol (14.9%), 1,8-cineole (9.0%), piperitenone (6.3%) and carvacrol (5.5%). The major components of T. pubescens oil were carvacrol (32.1%), thymol (19.1%), α-terpineol (14.6%) and p-cymene (6.1%).

Study of the essential oils ofThymus haussknechtii Velen andThymus kotschyanus Boiss. et Hohen var.kotschyanus (Lamiaceae) taxa from the eastern Anatolian region in Turkey

The essential oils of water distilled aerial parts of Thymus haussknechtii and Thymus kotschyanus var. kotschyanus (Lamiaceae) were analysed by GC / MS system. Seventy-eight components were identified comprising 88.0 and 91.3% of the total components in the oils, respectively. 1,8-Cineole (21.5%) was the dominant compound in Thymus haussknechtii oil and thymol (47.5%) was the main component in the oil of Thymus kotschyanus var. kotschyanus. Copyright © 2004 John Wiley & Sons, Ltd.

Analysis of the essential oils of two Thymus species from Iran

The essential oils obtained from the aerial parts of Thymus daenensis subsp. daenensis and Thymus kotschyanus were analyzed by using GC and GC/MS. Twenty six compounds representing 99.7% of T. daenensis subsp. daenensis oil were identified. The main ones were thymol (74.7%), p-cymene (6.5%), β-caryophyllene (3.8%) and methyl carvacrol (3.6%). Thirty one components accounting for 98.7% of T. kotschyanus oil were identified. The major constituents were thymol (38.6%), carvacrol (33.9%), γ-terpinene (8.2%) and p-cymene (7.3%). Both oils were found to be rich in monoterpene phenols, especially thymol and carvacrol.

Anti-Helicobacter pylori activities of six Iranian plants.

Helicobacter pylori is the major worldwide cause of bacterial gastrointestinal infections in adults and children. Antibiotic therapy and a combination of two or three drugs have been widely used to eradicate these infections. However, development of drug resistance in bacteria calls for new sources of drugs, and plants seem to be a logical source of new antibacterial compounds. The anti-H. pylori activities of six native Iranian plants (Glycyrrhiza aspera, Juglans regia, Ligustrum vulgare, Thymus kotschyanus, Trachyspermum copticum and Xanthium brasilicum) and seven antibiotics were determined against 70 clinical isolates from children using the disk susceptibility assay. Minimum inhibitory concentrations were also measured for the biologically active extracts. One extract with the best anti-H. pylori activity was fractionated by silica gel and thin layer chromatography and the active compounds were identified by hydrogen nuclear magnetic resonance ((1)HNMR) spectroscopy. All plant extracts showed anti-H. pylori activity by the disk sensitivity method, but the most active extracts were those from X. brasilicum and T. copticum. In fact, the anti-H. pylori activities of the two extracts were superior to the disk antibiotic susceptibility profile. Minimum inhibitory concentrations were within the range of 31.25-250 micro g/ml. Fractionation and chemical identification of the extract from X. brasilicum showed the presence of two substances, a flavonoid and a xanthanolide. Due to the rise in antibiotic resistance, new sources of anti-H. pylori drugs are needed. The use of medicinal plants and/or their chemical components may have potential benefit in eradicating such problems.

Bacterial susceptibility to and chemical composition of essential oils from Thymus kotschyanus and Thymus persicus.

Susceptibility of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, and Pseudomonas aeroginosa to the essential oils extracted from two varieties of Thyme, i.e., Thymus kotschyanus Boiss. and Hohen. and Thymus persicus L. at preflowering and flowering stages were studied. The disk diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oils. Minimal inhibitory concentration and minimal bactericidal concentration of the oils were determined and compared with each other. The oils from the above plants were found to be strongly bactericidal with that of T. kotschyanus being more effective. T. kotschyanusand T. persicus oils analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) lead to identification of 33 and 26 components, respectively. The profile of the oil components from T. persicuswas similar to that of T. kotschyanus in almost all of the compounds but at different concentrations. The major components of T. kotschyanus oil before and at the flowering stages were carvacrol (35.06, 22.75%), thymol (26.60, 16.52%), gamma-terpinene (7.81, 0.34%), gamma-terpinene (4.34, 0%), borneol (2.29, 4.52%), myrcene (0.26, 12.65%), thymolquinone (0, 11.39%), nerol (0, 6.10%), and beta-caryophyllene (0, 5.54%), respectively, and those of T. persicus at the same stages were carvacrol (38.96, 27.07%), thymol (6.48, 11.86%), P-cymene (7.51, 10.16%), gamma-terpineol (0, 9.51%), nerol (15.66, 9.41%), gamma-terpinene (6.11, 6.51%), and thymol acetate (5.29, 5.30%), respectively. The contribution of oil components to its antibacterial property is discussed. High aromatic compound content of the phenol-rich oils seems to account for strong antibacterial activity.

Karyotypic Studies of Two Thymus Species.

Thymus kotschyanus and Thymus pubescence are 2 vast spreaded species of Thyme, growing all around the country in Iran. This study has characterized karyotypes of 4 populations of T. kotschyanus and 3 populations of T. pubescence all collected from their natural habitats. In other words, 2 ploidy levels were observed within the species and their chromosomes were mainly of m and the rest of sm type. Therefore, 2 data groups were formed for the 2 ploidy levels. Factorial analysis of variance was carried out on the data groups in completely randomized design model, regarding the populations and chromosomes of each group as the 2 factors. Total form percentage (TF%), and several other parameters were estimated to compare the karyotypes of the populations and the species.Analysis of variance presented significant differences between the diploid and tetraploid populations and their chromosomes, based on the data recorded on the karyotypes of the populations. Size of the chromosomes among the diploid populations of T. kotschyanus species varied from 0.92 to 2.06 μm. Chromosome length of the only diploid population of T. pubescence species varied from 1.05 to 2.32 μm. Within the 2 tetraploid populations of T. pubescence species the size of the chromosomes varied from 0.83 to 1.88 μm. Chromosome length of the only tetraploid population of T. kotschyanus species varied from 0.91 to 1.66 μm. In fact all of the chromosomes of the 2 species are very small in size. In average the chromosomes of tetraploid populations are smaller than the chromosomes of diploid populations.

The effect of distillation methods and stage of plant growth on the essential oil content and composition ofThymus kotschyanus Boiss. &amp; Hohen

The essential oils were isolated by steam, hydro and water–steam distillation from the aerial parts of Thymus kotschyanus Boiss. & Hohen in three stages of plant growth (before, at the beginning of and at complete flowering). The oils were analysed by capillary GC and GC–MS. The highest oil yield was obtained by hydrodistillation method and the lowest by steam distillation. The oil yield, related to distillation method and stage of plant growth, was 0.28–1.80% w/w (the highest for complete flowering stage by hydrodistillation method). The main constituents in all of the oils were carvacrol (40.74–61.23%), thymol (7.51–26.92%), γ-terpinene (3.72–8.25%), p-cymene (3.28–6.74%) and borneol (1.33–4.52%). Copyright © 1999 John Wiley & Sons, Ltd.

The effect of distillation methods and stage of plant growth on the essential oil content and composition of Thymus kotschyanus Boiss. &amp; Hohen

The effect of distillation methods and stage of plant growth on the essential oil content and composition of Thymus kotschyanus Boiss. &amp; Hohen