Pycnocycla spinosa aerial parts were collected weekly during four-month growth. Hydrodistillation and gas chromatography coupled with mass spectroscopy techniques were used for essential oil and sesquiterpenes investigation. Thirty-four components were identified, of which the characteristic sesquiterpenes were a -copaene, caryophyllene, a -humulene, b-ionene, d-cadinene, a -calacorene, caryophyllen oxide, a -cadinol, and b-eudesmol. The content of b-eudesmol in the essential oil varied 1.9-9.17%, and of a -cadinol did 0-5.59%. Plant harvested in Jun provided essential oil with high caryophyllen oxide. These results may indicate that essential oil of differ qualities can be obtained according to the harvest time of the plant.

Both Centaurea pterocaula Trautv. and Centaurea urvillei DC. are a type of cornflower. The aim of this study is to determine the chemical composition of essential oils of C. urvillei and C. pterocaula for food, cosmetics-health industry and medicinal uses. The plant parts of C. urvillei and C. pterocaula were collected at flowering stage from Urmia (Ghasemloo Valley) and Zanjan in 2010 and 2011. The plant parts including stem, leaf and inflorescence were dried in laboratory and crushed to particles. The essential oils were obtained by hydrodistillation and were analyzed by GC-FID and GC/MS. The essential oil yield of stem plus leaf and inflorescence of Centaurea pterocaula (w/w dried weight) were 0.06% and 0.09%, respectively. The major constituents of stem plus leaf and inflorescence essential oils were germacrene D (20.4% and 5.4%), thymol (10.6% and 3.8%), cyperene (3.5% and 11.5%), spathulenol (7.7% and 4.9%), caryophyllene oxide (6.8% and 13.4%) and E-caryophyllene (4.9% and 8.1%), respectively. The essential oil yield of stem plus leaf and inflorescence of Centaurea urvillei (w/w dried weight) were 0.023% and 0.065%, respectively. The major constituents of stem plus leaf oils were benzyl benzoate (38.7%), caryophyllene oxide (17.9%) and b-eudesmol (19.8%) and the major constituents of inflorescence oil were caryophyllene oxide (25.7%), spathulenol (14.8%) and eudesma-4(15)-7-dien-1-β-ol (21.0%).

The genus Achillea has 19 species of herbaceous, perennial and aromatic plant in Iran. This genus of compositae family has complex characteristics. Chamazolene is a major component of essential oil of inflorescence and leaf, reported to be used in food, cosmetic, and pharmaceutical industries. A. millefolium L. subsp. elbursensis is an endemic subspecies of Iran and no studies have been conducted on the cultivation of this species; therefore a preliminary study was conducted on the cultivation and its effect on secondary metabolites. For this purpose, the seeds of Achillea were collected from Dizine area in October 2016. The seeds of Achillea were cultivated in a greenhouse at the beginning of March and seedlings were transplanted to the farm in late April 2017.At flowering stage in August, aerial parts were collected in two consecutive years to obtain the essential oils. To compare the essential oil of cultivated samples with habitat samples, the aerial parts of Achillea were collected from Dizin at the flowering stage in August 2017. The plant parts including leaf and inflorescence were dried in laboratory and were crushed to particles. The essential oils were obtained by hydrodistillation and were analyzed by GC-FID and GC/MS. The color of A. millefolium essential oils was dark blue. The yields of A. millefolium essential oils of leaf and inflorescence (w/w dried weight) from habitat samples were 0.11% and 0.53%, respectively, and from cultivated samples were 0.28% and 0.50% in 2017 and 0.26% and 1.30% in 2018, respectively. Chamazulene was the major constituent of leaf (5.7%) and inflorescence (52.5%) oils in the habitat samples. The content of this compound in cultivated samples was 50.6% and 67.1% in the first year, and 59.6% and 71.3% in the second year, respectively. Another major constituents were caryophyllene alcohol, caryophyllene oxide, camphor, borneol and b-eudesmol. Chamazulene as major compound of the oil, found in all aerial parts of cultivated samples, while, it was found only in the inflorescence of wild sample.

The genus Pycnocyla belongs to the Apiaceae family and has eight perennial species in Iran. In this study, the essential oil content and chemical compounds of P. nodiflora Decne ex. Boiss. and P. flabellifolia Boiss. were investigated. The aerial parts of plants at seeding stage were collected from two habitats in Hormozgan province through two consecutive years and Kermanshah province in one year, respectively. Stem+leaf [SL] and seed [S] were separated and shade-dried. The essential oil was extracted by Clevenger apparatus and hydrodistillation method for three hours. Percentage and chemical composition of the essential oils were determined by GC and GC/MS. The essential oil content of P. nodiflora was obtained [SL]: 0.23 and 1.21% (two years) and [S]: 0.23% in Tangzagh habitat of Hormozgan and [SL]: 0.02 and 0.06% (two years) and [S]: 0.01% in Abmah habitat. Caryophyllene oxid (7.8-28.1%) and b-eudesmol (15.5-57.2%) were recognized as the main compounds of [SL] and [S] essentials oils of both habitats in this species. In P. flabellifolia, the essential oil content of [SL] and [S] was 0.66 and 0.76%, respectively. The main compounds in [SL] essential oil of this species were cis-β-ocimene (33.8%), trans-β-ocimene (39.6%), and terpinolene (12.9%) and in [S] essential oil were trans-β-ocimene (28%), cis-β-ocimene (31%), and terpinolene (12.6%). According to previous reports on the antimicrobial properties of trans-β-ocimene and cis-β-ocimene compounds on bacteria like Staphylococcus aureus and S. epidermidis and the predominance of these compounds in the essential oil of P. flabellifolia, studies on antimicrobial properties of this species essential oil is recommended.

The Anthemis genus، belonging to Asteraceae family، has 23 endemic annual species in Iran، with the flowers and shoots containing essential oil. In this experiment، for the first time، the seeds of Anthemis tinctoria L. were collected from west Azarbayejan، Iran، and cultivated at the field of Alborz Research Station. In order to determine the essential oil composition of cultivated Anthemis tinctoria، random sampling was conducted at full flowering stage from flowering shoot. Flowers، leaves and stems were divided and dried in open air and their essential oil was produced separately by hydro-distillation. To analyze the essential oil composition، GC and GC-MS were used. Results indicated that essential oil percentage in flower، leaf، stem and total shoot was 0. 0892، 0. 0487، 0. 0466 and 0. 0792%، respectively. Analysis of leaf essential oil indicated that 32 compounds were detected; five main compounds were camphor (15. 8%)، α-eudesmol (10. 3%)، guaiol (9. 6%)، chrysanthenone (8. 4%) and 1،8-cineol (8. 0%); contributing to more than 53% of the essential oil composition. Twenty-one compounds were detected in stem essential oil; four main compounds were spathulenol (25. 6%)، α-eudesmol (14. 5%)، caryophyllene oxide (11. 8%) and β-eudesmol (5. 9%). Moreover، 22 compounds were detected in flower essential oil; five main compounds were α-eudesmol (27. 5%)، β-eudesmol (14. 3%)، spathulenol (13. 3%)، 10-epi-g-eudesmol (7. 2%)، 1،8-cineol (4. 2%). The results also indicated that 29 compounds were detected in shoot essential oil; four main compounds were g-eudesmol (39. 92%)، caronene (9. 1%)، camphor (6. 5%)، spathulenol (5. 1%) and 1،8-cineol (4. 3%). According to the obtained results، the percentage of α-eudesmol as main component of this essential oil varied from 10 to 40% in different plant parts، the lowest in leaf oil and the highest in aerial part oil. The highest amount of β-eudesmol was found in flower and stem oil. The presence of high amount of chrysanthenone and camphor in leaf oil was also remarkable. It can be concluded that by using flowering shoot or total aerial parts of A. tinctoria in full flowering stage، more essential oil yield would be produced. In addition، for special purposes and obtaining some special compounds، special plant parts could be distilled.

Parthenium argentatum Gray. (Guayule) is a perennial shrub and a source of latex. The essential oil of flowers and latex has distinctive odor and honey bees which are effective pollen carriers of this species, are mostly being attracted to its flowers. Therefore, the flowers oil of cultivar UC/100, collected in July 2004 from Research Institute of Forest and Rangelands field, was investigated. The essential oil isolated by hydro-distillation was analyzed by a combination of GC and GC/MS. The mean oil content was 0.8% (w/w). A total of sixteen components were identified representing 97.6% of the oil. The main constitutes of the essential oil were α-pinene (27.2%), b-phellandrene (17.0%), γ-eudesmol (11.3%), β-pinene (10.0%), β-eudesmol (9.0%), bicyclogermacrene (4.0%). Other components present in appreciable amounts were sabinene (7.3%), α-eudesmol (1.9%), bornyl acetate (1.6%), germacrene D (1.4%) and (Ε)-β-ocimene (2.2%).

volatile constituents of the aerial parts of Varthemia. persica DC. var. persica, growing wild in Iran, were investigated by GC-MS. Sixty seven constituents were identified. δ-Cadinene (9.7%), Selin-11-en-4-α-ol (5.30%), Germacrene D (4.9%), Bicyclogermacrene (4.7%), α‑Muurolene (4.7%), β-Eudesmol (4.52%), β-Himachalen oxide (3.6%), γ-Eudesmol (3.54%), β-Bourbonene (3.21%) were found to be the major constituents of the oil respectively.

In this research, after determining the effect of the amount of solvent, the effect of parameters of time, ratio of solvent to solid and power on the yield of essential oil extraction from angouzeh gum, which has many medicinal properties, was investigated by Microwave-assisted distillation method. With statistical analysis using the response surface method, it was determined that time, ratio and power parameters have a significant effect on yield. The optimal conditions to reach the maximum extraction yield, solvent to solid ratio of 30 (ml/g), power of 900 watts and time of 26 minutes were obtained, and by conducting the experiment under these conditions, the yield value (percentage of the weight of the essential oil to the weight of the dry raw material) was obtained 4.853 ± 0.045. According to the results of GC/MS analysis, 71 compounds were identified, which constituted 97.18% of the total essential oil. Some of the main compounds were: γ-Eudesmol, Alpha.-Pinene, 2-.Beta.-Pinene. γ-Eudesmol compound was the main compound that made up the highest percentage of essential oil.

This study was laid out in Lorestan agricultural farm, Korramabad, Iran during 2016 and 2017. The experiment was designed based on a complete randomized design (CRD) with four replications. In this study, in the spring, fresh leaf samples were randomly collected seven species of Eucalyptus. The composition of essential oils determined using analytical gas chromatography coupled to mass spectrometry (GC–MS).The results showed that the effect of specie treatment was significant on essential oil yield, α-Pinene, β-Pinene, 1, 8-Cineole, γ-Terpinene, Pinocarvone, Epiglobulol and β-Eudesmol. Based on our results, essential oil of Eucalyptus camaldulensis Dehnh. was obtained at rate of 3.43%. The measured oil yield was in range of 2.57% for Eucalyptus nitens (H. Deane & Maiden) Maiden, 1.34% for Eucalyptus globulosusbicosata, 5% for E. globulus madidenii17746, 5.38% for E. globulusmadidenii 2130, 3.74% for Eucalyptus viminalisLabill.and 1.12% for Eucalyptus suggrandis L.A.S. Johnson & K.D. Hill. The main compounds of Eucalyptus camaldulensis Dehnh. oils were 1, 8-cineole (66.72%) followed by α-pinned (17.88) in the samples. The major constituents of Eucalyptus nitens (H. Deane & Maiden) Maidenoils were 1, 8-cineole (46.67%), α-pinene (14.56%) and β-Pinene (4.51%). The main components of E. globulus oils were 1, 8-cineole (70.15%) and α-pinene (3.65%). The main compounds ofE.globulusmadidenii17746 oils were 1,8-cineole (55.82%), α-pinene (3.91%) and Veridiflorol (5.07%). The major constituents of E. globulusmadidenii 12130 were 1,8-cineole (60.29%), α-pinene (15.5%),α–Terpineol (6.11%) and Eudesmol (3.88%). The major constituents of Eucalyptus viminalis Labill. oils were 1, 8-cineole (56.43%), α-pinene (3.91%). The major constituents of Eucalyptus suggrandis L.A.S. Johnson & K.D. Hill oils were 1, 8-cineole (30.94%), α-pinene (18.52%), β-Eudesmol (6.87%) and Pinocarvone (4.96%). The E. globules maidenii 12130 specie had highest rate of essential oil yield. Between all species E. suggrandis had maximum rate of α-Pinene, γ-terpinene, Pinocarvone and β-Eudesmol. Between essential oil compositions 1, 8-Cineole was in higher rate especially in E. globules bicostata specie.

Some empirical studies show a reverse relationship between natural resource abundance and economic growth. Natural resource abundance affects economic growth through different transmission channels so that the human capital is the most important one. The main purpose of this research is to investigate the relationship between natural resource abundance and economic growth with emphasis on the role of human capital in this relationship. We analyze this relationship in two groups of petroleum exporting countries: A) Major petroleum exporters B) Other petroleum exporters by cross country economic growth during 1970-2004. The panel data approach is used to estimate econometrics model. Also, the required data is divided to seven parts as five years. In this article the study period is limited to 1970-2004, since the required data for the last five years period of 2005-2009 has not published, yet. Findings show that natural resource abundant inversely related with economic growth, while human capital have a negative effect on group A’s economic growth and positive effect on group B’s economic growth. In addition, we extend the usual specifications for economic growth regressions by incorporating an interaction term between human capital and natural resources, showing that low levels of human capital may not outweigh the negative effects of the natural resource abundance on group A’s growth, but the high levels of human capital may offset the negative effects of the natural resource abundance on group B’s growth.