Fresh plant samples of A. arborescens growing in Sicily were collected from five different sites: Petru (N 37° 59′ 46″, E 13° 38′ 53″, 69 m); Diga (N 37° 57′ 23″, E 13° 39′ 05″, 198 m), Felice (N 37° 56′ 44″, E 13° 36′ 38″, 484 m), Torto (N 37° 57′ 53″, E 13° 46′ 30″, 55 m) and Artese (N 37° 58′ 28″, E 13° 44′ 13″, 10 m) in January 2010.

Forty-three compounds, accounting for more than 92% of the oil, were identified. Monoterpene fraction with the exception of Petru population was higher than the sesquiterpene fraction. beta-Thujone (20.5-55.9%), chamazulene (15.2-49.4%), camphor (1.3-10.7%) and germacrene D (2.3-3.4%) were the main compounds.

The leaves of aerial parts were collected in Heshuo county of Xinjiang province in China in July 2003 (a vegetative stage), June 2003 (a budding stage); and August 2003 (a flowering stage), respectively.

Only 23 constituents were present at the budding stage, while 24 and 26 at the flowering and vegetative stages, respectively. p-Cymene and gamma-terpinene were not detected at the vegetative stage of the plant. During the budding stage, butyric, beta-caryophyllene, geranyl acetate and cis-jasmone could not be detected. Benzaldehyde was observed only at the vegetative stage. Variations were also observed in quantity. In all cases the analyzed oils were characterized by the high concentration of alpha-thujone, ranging in amount from 37.0% at the vegetative stage to 54.8% at the budding stage. The concentration of alpha-thujone at the flowering stage (49.0%) was lower than the budding stage, but higher than the vegetative stage. The concentration of cis-chrysanthenyl acetate varied between 23.5% and 7.2%, respectively, at the vegetative and budding stages. At the vegetative stage the concentration of 1,8-cineole was observed to be the lowest. It was highest at the budding stage, representing 10.4%, then decreased gradually to 8.8% at the flowering stage. The concentration of beta-thujone was relatively low at the vegetative stage, representing 8.6%, and then increased to 10.5% at the budding stage. When flowers appeared it was found to vary a little. Finally, the concentration of sabinyl acetate ranged from 10.2% (vegetative stage) to 6.5% (flowering stage).

Leaves from mature plants of Artemisia nilagirica var. septentrionalis, before flowering, were collected from different altitudes in Himachal Pradesh such as Shimla (2210 m), Mandi (1044 m) and Manali (2050 m) in June 2005.

The major constituents of the oil show variation with changes in altitude. At lower, middle and higher altitudes, the major constituents of the oil were caryophyllene oxide (28.6%), borneol (35.8%) and camphor (46.9%), respectively. The percentages of alpha-humulene and trans-beta-guaiene also increased, but the percentage of sabinene, trans-sabinene hydrate, 4-terpineol, caryophyllene oxide and humulene epoxide-II decreased with an increase in altitude. The characteristic compounds observed in the plants from lower altitudes were 2-hexene-1-ol, beta-thujone, thujanol, myrtenol and linalyl acetate, while the higher altitude plants were characterized by the presence of alpha-pinene, beta-pinene, limonene, linalool, gamma-gurijunene, germacrene-D and farnesol.

Plant material of A. verlotiorum was harvested near Marseille (France) in May (before blooming) and November (full flowering) 2000.

For the oil from the vegetative plants, 50 compounds, representing 99.8% of the oil were characterized. Fifty-nine compounds, representing 99.6% of the oil were identified in the oil from flowering plants. In both cases, the constituents were mainly oxygenated monoterpenes (74% and 88%). The composition of each oil showed only a few differences, as the main components were alpha-thujone (55% and 44%), 1,8-cineole (5% and 15%), beta-caryophyllene (13% and 7%) and beta-thujone (5% and 11%), in the oils of the vegetative plant and flowering plant, respectively. The proportions of the oxygenated compounds seemed to increase during flowering.

Hyptis marrubioides were collected in March 2003 at the mature vegetative stage from their natural habitat; 20 randomised individual plants at the same age representing the local population were collected as homogenous samples from each locality: (A) Lavras (21° 14′ S/44° 59′ W), at an altitude of 919 m; (B) Tiradentes (21° 6′ S/44° 10 m W), 927 m.

The results were submitted to Principal Component and Cluster analysis which allowed three groups of oils to be distinguished with respect to sampling site and post-harvested process: cluster I (fresh leaves and fresh or dried stems from Lavras site) with high percentage of caryophylla-4(14),8(15)-dien-5beta-ol (16.7%) and eudesma-4(15),7-dien-1beta-ol (12.8%); cluster II (dried leaves and stems from Tiradentes site) with epi-longipinanol (16.2%) rich oil, and cluster III (dried leaves from Lavras) containing a high content of beta-caryophyllene (17.4%) and alpha-copaene (10.1%). Canonical discriminant analysis showed that is possible to accurately predict 100% well-classification in the original clusters using beta-caryophyllene, epi-longipinanol and caryophylla-4(14),8(15)-dien-5beta-ol as predictor variables. The whole or sliced plant materials resulted in similar chemical composition.

The plant materials were collected for P1: 2900 m, Ait Akak, Oukaimden, Atlas Mts, Morocco, N. Achak, A. Romane and M. Mahroug, 3 trees, ns, 12/12/2003; P2, 2200 m, Plateau of Matat, Atlas Mts, N. Achak, A. Romane and M. Mahroug, 3 trees, ns, 18/03/2003; P3: 2000 m, Foret Islane, Oukaimden, Atlas Mts, N. Achak, A. Romane and M. Mahroug, 3 trees, ns,12/12/2003. A portion of the leaves from each of the three trees (per population) were air dried for 16 days at room temperature (ca. 22 &#8451) to produce the dried leaf samples.

The oil yields from fresh leaves showed on differences among geographical sources. Air dried leaves appeared to yield more oil at the highest elevation (1.03%, Ait Lkak, 2900 m) than lower sites (0.67%, Plateau of Matat, 2200 m; 0.57%, Foret Islane, 2000 m). The essential oils from each geographic site had very similar composition in fresh versus air dried leaves. The essential oils from provenance Ait Lkak and Plateau of Matat were very similar and characterized by a high sabinene content (21.2, 35.9%), in contrast to 10.% sabinene from the provenance Foret Islane. The oil from Foret Islane had a high delta-cadinene content with 12.7%, whereas Aik Akak and Plateau of Matat contained only 0.6 and 0.8%.

Plants were collected in the Inner plain, the Sharon plain and the kava valley.

The major constituent of all three oils was found to be 1,8-cineole (26.4-34.5%) followed by menthone (10.0-16.7%), pulegone (7.0-7.5%), and isomenthone (4.7-7.8%). Despite some differences in the component proportions, the plants of all three populations clearly belong to the same chemotype.

The aerial parts of M. biflora collected during November 1993 and June 1994 were used for the investigation.

The major constituents of the oil were neral (25.3-32.2%) and geranial (26.7-41.3%). The oil produced in the winter was found to contain higher amounts of oxygenated monoterpenes than the oil produced in the summer.

S. aucheri var. aucheri was collected in Karaman: Ermenek to Mutt Road on July 19,1995; Salvia aucheri var. canescens was collected in Karaman: Ermenek, Tekecati Valley on July 19,1995.

Eighty components were characterized in the Salvia aucheri var. aucheri oil, with camphor (21.1%), 1, 8-cineole (20.3%), borneol (7.8%), spathulenol (6.3%) and camphene (5.3%) as major constituents. 1, 8-Cineole (25.2%), camphor (17.9%), borneol (10.6%), alpha-pinene (5.4%) and camphene (5.3%) were identified as major constituents among the 88 components characterized in the oil of Salvia aucheri var. canescens.

Sage plant material was collected from two different localities (altitudes 110 and 400 m) in central Herzegovina near Mostar and at four different stages of development: vegetative period (leaves and stalks, January 2003), prior to flowering (leaves and stalks, April 2003), in the course of flowering (flowering tops, leaves and stalks, May 2003) and after flowering (leaves and stalks, August 2003).

The highest oil yield of the plant was after flowering (August). The oil samples obtained prior to flowering (April) and in the course of flowering (May) yielded remarkably less than those after flowering (August) and in the vegetative period (January). An unexpected high oil yield of the plant in the vegetative period (January) is probably due to lower moisture content in this stage of development. The oil yields ranged from 0.29% to 0.64% (altitude 110 m) and 0.45% to 1.07% (altitude 400 m), which reveals that altitude also has significant influence on oil yields. The oils from plant materials gathered prior to flowering (April) and in the course of flowering (May) were found to contain significantly higher percentages of alpha-humulene, manool, viridiflorol and caryophyllene, while the oils produced after flowering (August) and in vegetative period (January) have had higher percentages of alpha-thujone and camphor. Although the altitude has had an obvious influence on oil yields, it did not have significant influence on the qualitative and quantitative composition of their constituents.

Plant material and isolation procedure: Aerial parts of the plant were collected from two regions, from Kazeroon in southern Iran and Shahr-e-kord in western Iran at the time of flowering in June 2002.

The main components of the oil of S. pilifera collected from Kazeroon, in southern Iran, were spathulenol (15.8%), cis-chrysanthenol (15.3%), beta-caryophyllene (8.4%) and cis-chrysanthenyl acetate (6.9%), while for the plant collected from Shahr-e-kord, in western Iran, they were cis-chrysanthenyl acetate (21.8%), linalool (18.9%), terpinen-4-ol (11.9%) and cis-chrysanthenol (9.2%).

Plant materials were collected during the flowering period in July 2002 from the Dumluca Mountain in the vicinity of Divrigi village of Sivas city at 1900 m altitude and Saksagan Gorge in Saimbeyli village of Adana city at 1900 m altitude.

The flower, stem and root oils of T. cadmeum ssp. orientale collected from the Adana location were characterized with alpha-thujone (25%, 5.2%), cis-linalool oxide (6.8%, 12.8%), trans-chrysanthenyl acetate (5.8%, 8.5%) for flower and stem oils, and beta-eudesmol (10.3%, 6.2%, 13.8%); in addition, stem oil contained 1,8-cineole (6.6%) and root oil contained hexadecanoic acid (6.0%), spathulenol (5.8%) and beta-muurolol (5.3%). The flower and stem oils of T. cadmeum ssp. orientale collected from the Sivas location were characterized with camphor (25.9%, 14.8%), borneol (15.4%, 25.8%) and alpha-thujone (7.8%, 5.5%); in addition, stem oil contained 1,8-cineole (7.4%) and root oil contained nonacosane (16.2%), spathulenol (6.8%) and hexadecanoic acid (5.8%).