جستجوی مقالات مرتبط با کلیدواژه "لینالول" در نشریات گروه "زیست شناسی"

In this study, the essential oils of Thymus daenensis and Thymus fedtschenkoi were investigated in terms of phytochemical, antibacterial, and antifungal properties. After identifying the essential compounds of these two species of thyme, their antimicrobial properties against Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus, and Enterococcus faecium), Gram-negative bacteria (Escherichia coli, Salmonella enteritidis), and fungus (Candida albicans) were investigated. For this purpose, the flowering branches of T. daenensis and T. fedtschenkoi were collected at full flowering stage from west of Iran (Arak and Hamedan, respectively) in June. Then, the constituents of the essential oils were identified by gas chromatography-mass spectrometry (GC/MS). To determine the sensitivity of microbial agents to the essential oil of these plants, disk diffusion and microdilution methods were used. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the essential oils of both plants were determined against bacteria and fungi. Based on the results, the essential oil content of T. daenensis (3.4%) was more than that of T. fedtschenkoi (2.9%). The main compositions of the essential oils of T. fedtschenkoi ​​ and T. daenensis were linalool (83.1%) and thymol (73.9%), respectively. The essential oils of both species had significant antibacterial and antifungal effects albeit with different levels. In general, the antibacterial activity of T. fedtschenkoi essential oil was higher than that of T. daenensis, especially in the case of gram-positive bacteria. On the other hand, the antibacterial activity of T. daenensis essential oil against E. coli (gram negative) was more than that of T. fedtschenkoi. Antifungal activity of T. daenensis essential oil was higher than that of T. fedtschenkoi against C. albicans. The essential oil of T. fedtschenkoi was rich in linalool, and the higher antimicrobial activity of this species could be attributed to the high percentage of this compound in comparison with T. daenensis.

Ocimum basilicum L.from Lamiaceae is used as a herb, spice and fresh vegetable. Since medicinal plants have different reactions to drought stress in the production of effective compounds, Diagnosis of medicinal plants growth under different irrigation conditions and drought stress can be a guide for growing plants in dry and low water conditions. Therefore, in order to evaluate the effect of drought stress on morphological characteristics and essential oil content, especially linalool, in different stages of plant growth of Basil plant, a completely randomized factorial design was carried out in 3 replications. The experimental treatments included three levels of dryness (no stress, mild stress and severe stress) in potted conditions, in vegetative, pre-flowering, flowering and fruit-growing stages. The results showed that drought stress had a significant effect on evaluated characteristics. So, with decreasing of soil moisture content, plant height, number and leaf area, decreased in all stages of growth and Stem diameter increased at all stages, especially in severe stress and root length, increased during flowering stage. In reproductive stages, drought stress caused a significant reduction in the number of flowers than the control. Extreme stress in flowering and fruiting stages has had decrease in the amount of essential oil production, especially linalool. However, mild stress showed increase in the production of these compounds in both steps. The highest percentage of essential oil was related to mild drought stress at flowering stage and the highest amount of linalool was due to mild drought stress in the fruiting stage.

In order to study the effect of biological and chemical fertilizer on qualitative and quantitative yield of Borago (Borago officinalis L.), an experiment was conducted in Jovein researcher farm on 2010-2011 as Randomized completely block design with 3 replications. Treatments were type of Fertilizer (100% chemical, 75%chemical 25%bilogical, 50 chemical 50%bilogical, 25%chemical 75%bilogical and 100%bilogical). The result showed that fertilizer type had significant effect on height, fresh weight of flower and number of lateral branch. Tannin and mucilage amount had not effected by fertilizer type. Increasing of chemical fertilizer was increased fresh weight of flower and number of lateral branch. The heights and the lowest fresh weight of flower and number of lateral branch was obtained in 100% chemical and 100% biological, respectively. Quality response were different to type of fertilizer. The greatest ash amount was obtained in 75%chemical%bilogical, maximum tannin amount in 100%chemical and 25%chemical%bilogical had the highest mucilage amount.

The genus Thymus belongs to family lamiaceae and consists of 215 different species throughout the word. Eighteen species of this genus grow naturally in Iran of which four are endemic. Thymus spp. essential oil contains valuable compounds such as thymol and carvacrol, which making it very important. After cultivation of different accessions of Thymus pubescens at the station of medicinal plants research, Shahedieh Yazd, the aerial parts of the plants were collected at 50% flowering stage and then were dried in shadow using hydro – distillation to obtain their essential oil. After the determination of essential oil efficiency based on the plant dry weight, analysis and identification of chemical compounds of the oil were performed by GC and GC/MS. Results showed that the highest oil yield was related to accessions MKOMKO 3.24%), CFT (3.24%), MKOCFT (2.87 %) and the lowest was related to accession BHUZSE 0.66%). The highest oil production per hectare was related to accessions CFT (24.69 kg/ha), MKOCFT (20.8kg/ha), CFTCFT (20.17kg/ha) and the lowest was related to CFTMKO (0.9 kg/ha). The maximum content of paracymen,1,8 cineol, gamma-terpinene, borneol, thymol, carvacrol, limonene, linalool and E-caryophyllene was respectively found in accessions MKOMKO (10.73%), CFT (31.66%), MKOMKO (20.44%), MKOMKO (29.35%), CFT (60.39%), VGYVGY (47.17%), QVGY (14.1%), CFTMKO (72.3%) and VGYMKO (20.4%). Considering the oil yield, oil production and main composition of essential oil, accessions CFT with 3.24% oil yield, 24.6 kg/hectare oil production and 60.39% thymol, accession MKOMKO with 3.24 oil yield, 19.52 kg/hectare oil production and 40.26% carvacrol, and accession MKOCFT with 2.87% oil yield, 20.8 kg/hectare oil production, 33.25% terpineol and 33.11% linalool were selected as superior accessions.

The monotypic Iranian Zhumeria majdae (Lamiaceae), known locally by the name of Mohrekhosh, was recently described as the first member of a new genus (Zhumeria). It has a limited geographical rang in southern Iran at Hormozgan province. The leaves have been used for many years as a curative for stomachaches and an antiseptic. In this research, the constituents of essential oils of Zhumeria majdae leaves and stem in Geno mountain of Hormozgan province were analyzed via GC and GC/MS and compared together. The oil yield of the dried leaves and stem by hydrodistillation were 7.5 and 0.3 %, respectively (v/w). 22 and 19 compounds were identified. The major constituents were Linalool and Camphor, which they belong to first group. Wheras, compounds, like alpha-Pinene, Camphene, Limonene, Alpha-terpineol, Caryophyllene oxide and Myrcene belong to second group.