mahdi yahyazadeh

Rosa damascena Miller essential oil (EO) is a valuable and widely utilized product in the food, pharmaceutical, and cosmetic industries due to its pleasant aroma and unique biological properties. The quantity and quality of EO can be influenced by various factors, including genetic, environmental conditions, the timing of flower collection, harvesting and storage methods, and the extraction process. The absence of standardized indicators for rose EO has led to confusion in consumer industries when it comes to identifying the quality of EOs produced by different companies. To address this issue, the present study was conducted to determine the range of changes in the physicochemical properties of Iranian rose EO according to ISO standard methods. For this study, the EO obtained from the distillation of fresh rose flowers (referred to as the first oil) was blended with the redistilled rose water (known as the second oil). This mixture was then subjected to physical and chemical analysis to determine the characteristics of the total EO of rose. The findings indicated that the total EO appears as a liquid or semi-solid, is transparent, and has a color ranging from light yellow to green. It possesses a fresh rose scent and a natural taste, free from any unpleasant odors or flavors typically associated with decay, sourness, or mold. The minimum and maximum values determined for the physical and chemical properties of Rosa damascena EO are: relative density at 25 ºC: 0.820-0.872, refractive index at 25 ºC: 1.4520-1.4650, optical rotation at 25 ºC: (-7.0°) - (-1.5°), freezing point: 16-24 ºC, acid value: maximum 3.4, ester value: maximum 23.0, and average flash point: 85 ºC. The main compounds in the EO of Rosa damascena are citronellol (25-45%), geraniol (6-25%), nerol (1-12%), n-nonadecane (7-30%), n-henicosane (2-8%), nonadecene (1-5%), n-tricosane (0.1-5%), n-eicosane (0.1-3%).

Chamomile (Matricaria chamomilla L.) is a valuable medicinal plant with many applications in the food, pharmaceutical, and cosmetic health industries. Chamomile's biological properties are attributed to its essential oil (EO) compounds, especially chamazulene and a-bisabolol oxide A, and flavonoids, esp. apigenin and luteolin. Evaluation of wild plant populations belonging to different geographical regions in situ (study on wild samples) and ex-situ (study on wild samples under agricultural conditions) is a crucial step in plant breeding and selection of promising genotypes. On the other hand, cultivation and domestication of wild plants under agricultural conditions improve plant yield and prevent unnecessary harvesting and extinction of the plant. In the present study, the quantitative and qualitative EO diversity of some wild chamomile was investigated. Flowers and seeds of 15 wild chamomile populations were collected from Iran's natural habitats, including 12 populations from Khuzistan province (Kh1-12), 2 populations from Fars province (F1-2), and 1 population from Bushehr province (F3) in 2021 (February-May). Flowers were used for essential oil extraction, and seeds were planted in a randomized complete block design (treatment = genotype) with three replications. The research farm located at Alborz Research Station, affiliated with the Research Institute of Forests and Rangelands, Alborz province, was considered a cultivation site without adding fertilizer to the soil. The seeds were sown directly in the field with a 15 cm distance between the planting lines and 15 cm between the plants on the lines (April 2021). Drip irrigation was used, and weeding was done mechanically. Flowers with less than 5 cm of peduncles were harvested manually at the 70% full bloom stage. The shade-dried flower EOs were extracted by water distillation (Clevenger) for 3 hours, and their quantitative and qualitative analysis was done using GC and GC/MS. The results showed that sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and diacetylenes made the highest EO compounds percentage in both wild and cultivated samples. Chamazulene (from sesquiterpene hydrocarbons) and a-bisabolol oxide A (from oxygenated sesquiterpenes), as two important chamomile EO compounds, showed an increase from wild to cultivated samples. Among the wild samples, the highest chamazulene (5.3%) and a-bisabolol oxide A (21.5%) contents were assigned to the populations Kh8 and Kh4, respectively. In the cultivated samples, the highest amount of these compounds (11.1 and 32.3%, respectively) was obtained in the populations Kh7 and F2, respectively. In general, the main EO compounds (%) in the wild and cultivated populations included α-bisabolone oxide A (wild: 31.3 (F1) to 64.5 (Kh3) and cultivated: 29.8 (F2) to 56 (Kh3)), α-bisabolol oxide A (wild: 5.8 (Kh5) to 21.5 (Kh4) and cultivated: 10.3 (Kh3) to 32.3 (F2)), E-β-farnesene (wild: 6.1 (Kh3) to 23.3 (Kh8) and cultivated: 6.9 (Kh1) to 15.6 (F3)), Z-spiroether (wild: 0 (F1) to 16.1 (Kh1) and cultivated: 9.1 (Kh7) to 15.1 (Kh13)), and chamazulene (wild: 1.6 (F1) to 5.3 (Kh8) and cultivated: 4.7 (Kh6) to 11.1 (Kh7)). Also, the EO% was obtained more in the cultivated samples (0.9 (Kh5) to 1.4% (Kh13)) than in the wild ones (0.1 (Kh6) to 0.5% (Kh10). The results of this research showed that by cultivating wild populations under agricultural conditions and water and crop management, it is possible to have essential oil in the desired quantity and quality compared to wild ones. It should be noted that the results of repeating population cultivation under the same conditions in the following years will be reported in proportion to the data output.

Rosa damascena Mill. is an aromatic plant, having different components that usually use in natural products. The main industrial products from oil-bearing rose are rose oil, rose water, rose concrete, and rose absolute which are produced by hydro-distillation and solvent extraction processes. However, essential oil productionis the best part that the industry is eager to it. Hydro-distillation with cohobation is a widely used method for producing volatile oils from oil-bearing rose. Newly, different methods of extraction of volatile compounds of rose oil, rose water and residue water from the flower of R. damascena, such as headspace solid-phase microextraction (HS-SPME) is developed. However, every method of extraction affects the quality of Rosa product. In this way the hydro-distilled rose oil analyzed by gas chromatography (GC-FID/GC-MS) revealed that the percentages of alkanes or steaoreptens like hexadecane (1.3%), nonadecane (7.2%) and heneicosane (1.8%) were higher than those of HS-SPME. However, there is a preference of rose oil extraction by hydro- distilation that the rose water (hydrosol) and residue water have phenylethyl alcohol (PEA), which is easily soluble in water, rose water and residue water. Actually rose water is a by-products of the hydro-distillation method, and it contained very high amounts of phenylethyl alcohol and  can be employed as the best natural fragrance of the oil-bearing rose due to its very high phenylethyl alcohol content. Phenyl ethyl alcohol is a naturally occurring aromatic compound found in various flowers including roses, lavender, ylang-ylang, geranium and champagne. For determining the content of phenyl ethyl alcohol in the flower R. damascene, according to the geographical similarity, the flowers were collected from different provinces of Iran by scientists of RIFR. In a research in 2021, after the extraction of essential oil and rose water, it was conducted on the remaining water in the still. The leftover water inside the distillation pot was extracted with eight different solvents (chloroform, cyclohexane, dichloromethane, diethyl ether, ethyl acetate, hexane, petroleum ether and toluene) by a separatory funnel and extracted crude were analyzed by (GC) and  (GC/MS). The amount of phenylethyl alcohol obtained by different solvents containing chloroform, cyclohexane, dichloromethane, diethyl ether, ethyl acetate, hexane, petroleum ether and toluene was 96.1%, 46.3%, 96.1%, 46.3%, 89.6%, 100%, 0.42% and 74%, respectively. Therefore, the research revealed the phenylethyl alcohol compound can be separated from the wastewater in the still and used.

The genus Anthemis L. is the second largest genus in the Compositae family, which consists of 39 annual and perennial species scattered throughout Iran. In this research, a species of Anthemis lorestanica Iranshahr was collected from two regions in Isfahan province, namely Makdin region (sample 1) and Badum Valley region (sample 2) in 2017.  The samples were identified in the herbarium of the Research Institute of Forests and Pastures in the Department of Botany. The essential oils were extracted from its flowers and leaves by water distillation method (Klenger method). Then the essential oil samples were measured and identified by gas chromatography (GC) and gas chromatography connected to mass spectrometer (GC/MS). The amount of essential oil in sample 1 was 0.12% for flower and 0.08% for leaf. Major compounds in the flower consisted of methyl decanoate (18.6%), α-cadinol (11.1%), and n-tricosan (9.1%). Major compounds in leaves were neryl acetate (13.4%), α-cadinol (12.9%), and dihydro eudesmol (8.5%). Essential oil contents of sample 2 were 0.2% for flower and 0.08% for leaf. The main flower compounds included spathulenol (68.8%), dehydro-aromadendrane (5.2%), and oplopanone (3%). The main compounds of the leaves were oplopanone (12.3%), 1-icocen (11.5%), and dihydro eudesmol (10.9%).

The aim of this study was to investigate the effect of habitat on the quantity and quality of essential oil of Teucrium stocksianum Boiss. Accordingly, the branch of this species at the time of flowering (August 2017 and 2018) were collected from 4 regions of Hormozgan province (northern side of Tang Zagh mountain at 1100 meters of altitude; Abmah mountain at 850 meters of altitude; Tang Zagh mountain at 1400 m and Enveh mountain at 2000 m) . Essential oils were extracted by hydrodistillation method ( Clevenger apparatus) and were analyzed by using GC and GC/MS. The results showed that with decreasing altitude, the amount of essential oil reduced, so that the lowest and highest amounts of essential oil belonged to the samples of Abmah mountain at 850 m and Enveh mountain at 2000 m, respectively. Chemical analysis of T. stocksianum essential oils showed that the common compounds in the essential oils of this species were elmol (2.4 to 8.5%), caryophylene oxide (3.0 to 7.1%) and β-eudsmol (2.2 to 12.1%). Compounds such as α-pinene and myrcene, the most volatile compounds found in essential oils, were not observed in lower-altitude samples, which may be related to high air temperatures in plant geographical location. Also, significant amounts of compounds such as valerianol, polgon, limonene and epi-alpha-cadinol were observed in some samples, which shows the effect of the ecological and climatic conditions on the quality of plant essential oil.