Chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. berries.

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Juniperus phoenicea L. ripe and unripe berries. GC and GC/MS analyses resulted in the detection of 42 components representing approximately 96.50-99.57% of the oils. Major components of the oils were α-pinene (58.61-77.39%), camphene (0.67-9.31%), δ-3-carene (0-10.01%) and trans-verbenol (0-5.24%). Antioxidant activities were determined by two different test systems, DPPH and ABTS radical scavenging activities. In both systems ripe berries exhibited better activity potential than the unripe ones.

Variation in volatile leaf oils of five Eucalyptus species harvested from Jbel Abderrahman arboreta (Tunisia).

Hydrodistillation of the dried leaves of five species of the genus Eucalyptus L' Hér., viz., E. dundasii Maiden, E. globulus Labill., E. kitsoniana Maiden, E. leucoxylon F. Muell., and E. populifolia Hook., harvested from Jbel Abderrahman arboreta (region of Nabeul, northeast of Tunisia) in April 2006, afforded essential oils in yields varying from 0.9±0.3 to 3.8±0.6%, dependent on the species. E. globulus and E. Kitsoniana provided the highest and the lowest percentage of essential oil amongst the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 127 compounds, representing 93.8 to 98.7% of the total oil composition. The contents of the different samples varied according to the species. The main components were 1,8-cineole (2; 4.7-59.2%), followed by α-pinene (1; 1.9-23.6%), trans-pinocarveol (6; 3.5-21.6%), globulol (8; 4.3-12.8%), p-cymene (3; 0.5-6.7%), α-terpineol (1.5-4.5%), borneol (0.2-4.4%), pinocarvone (1.1-3.8%), aromadendrene (1.4-3.4%), isospathulenol (0.0-1.9%), fenchol (4; 0.1-2.5%), limonene (1.0-2.4%), epiglobulol (0.6-2.1%), viridiflorol (9; 0.8-1.8%), and spathulenol (0.1-1.6%). E. leucoxylon was the richest species in 2. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) separated the five Eucalyptus leaf essential oils into four groups, each constituting a chemotype.

Variation in volatile leaf oils of seven eucalyptus species harvested from Zerniza arboreta (Tunisia).

Leaves of seven species of the genus Eucalyptus L'Hér., viz., E. cladocalyx F. Muell., E. citriodora Hook., E. diversicolor F. Muell., E. fasciculosa F. Muell., E. grandis W. Hill, E. ovata Labill., and E. botryoides Sm., were harvested from Zerniza arboreta (region of Sejnene, northwest of Tunisia) in June 2007. Of the latter species, leaves were collected from trees having two origins, Morocco and Italy. Hydrodistillation of the dried leaves provided essential oils in yields varying from 0.4±0.0 to 3.3±0.1%, according to the species. E. citriodora had the highest mean percentage of essential oil amongst the species examined, whereas the lowest one was obtained for E. botryoides originating from Morocco. Analysis by GC (RI) and GC/MS allowed the identification of 140 compounds, representing 92.5 to 99.4% of the total oil composition. The contents of the different samples varied according to the species. The main components were 1,8-cineole (2), followed by α-pinene (1), p-cymene, borneol, α-terpineol, cryptone, spathulenol, trans-pinocarveol (4), bicyclogermacrene (5), caryophyllene oxide, and ß-phellandrene. Principal components analysis and hierarchical cluster analysis separated the eight Eucalyptus leaf essential oils into five groups, each constituting a chemotype.

Variation in volatile leaf oils of eleven eucalyptus species harvested from korbous arboreta (Tunisia).

Hydrodistillation of the dried leaves of eleven species of the genus Eucalyptus L'Hér., i.e., E. astringens Maiden, E. camaldulensis Dehnh., E. diversifolia Bonpl., E. falcata Turcz., E. ficifolia F. Muell., E. gomphocephala DC., E. lehmannii (Schauer) Benth., E. maculata Hook., E. platypus Hook., E. polyanthemos Schauer, and E. rudis Endl., harvested from Korbous arboreta (region of Nabeul, northeast of Tunisia) in April 2006, afforded essential oils in yields varying from 0.1+/-0.1 to 3.8+/-0.1%, dependent on the species. E. astringens and E. ficifolia showed the highest and the lowest mean percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 138 components, representing 74.0 to 99.1% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8-cineole, followed by trans-pinocarveol (1), spathulenol (2), alpha-pinene, p-cymene, (E,E)-farnesol, cryptone, globulol (3), beta-phellandrene, alpha-terpineol, viridiflorol, and alpha-eudesmol. The principal-component and the hierarchical-cluster analyses separated the eleven Eucalyptus leaf essential oils into seven groups, each constituting a chemotype.

Variation in volatile leaf oils of 13 Eucalyptus species harvested from Souinet arboreta (Tunisia).

Hydrodistillation of the dried leaves of 13 species of the genus Eucalyptus L' Hér., viz., E. bicostata Maiden, Blakely & Simmonds, E. cinerea F. Muell. ex Benth., E. exerta F. Muell., E. gigantea Hook. f., E. gunnii Hook. f., E. macarthurii Deane & Maiden., E. macrorrhyncha F. Muell., E. maidenii F. Muell., E. odorata Behr., E. pauciflora Sieber ex Sprengel, E. sideroxylon A. Cunn. ex Woolls, E. tereticornis Sm., and E. viminalis Labill., harvested from Souinet arboreta (region of Ain Draaham, north of Tunisia) in June 2006, afforded essential oils in yields varying from 0.5+/-0.2 to 3.9+/-0.4%, dependent on the species. E. cinerea and E. exerta provided the highest and the lowest percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 142 components, representing 81.5 to 98.9% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8-cineole (1), followed by cryptone, spathulenol (4), p-cymene (2), viridiflorol (6), globulol (7), beta-eudesmol, alpha-terpineol (5), limonene (8), D-piperitone, alpha-pinene (3), cuminal, and gamma-eudesmol. The principal component and the hierarchical cluster analyses separated the 13 Eucalyptus leaf essential oils into three groups, each constituting a chemotype.

Variation in volatile leaf oils of twelve eucalyptus species harvested from Hajeb Layoun arboreta (Tunisia).

Hydrodistillation of the dried leaves of twelve species of the genus Eucalyptus L' Hér., i.e., E. brockwayi C. A. Gardn., E. gracilis F. Muell., E. gillii Maiden, E. largiflorens F. Muell., E. loxophleba Benth., E. occidentalis Endl., E. oldfieldii F. Muell., E. salmonophloia F. Muell., E. sargentii Maiden, E. stricklandii Maiden, E. torquata Luehm., and E. woodwardii Maiden, harvested from Hajeb Layoun arboreta (region of Kairouan, central Tunisia) in January 2005, afforded essential oils in yields varying from 0.5+/-0.1 to 5.7+/-0.5%, dependent on the species. E. sargentii and E. brockwayi provided the highest and the lowest percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 133 components, representing 92.9-98.8% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8-cineole, terpinen-4-ol, alpha-pinene (2), p-cymene, aromadendrene (1), globulol (5), trans-pinocarveol (6), spathulenol (7), beta-eudesmol, torquatone (3), and 4-methylpentan-2-yl acetate (8). The principal component analysis and the hierarchical clustering indicated that the volatile leaf oil composition of the twelve Eucalyptus species could be clearly differentiated.

Seasonal and geographical influences on the chemical composition of Juniperus phoenicea L. essential oil leaves from the Northern Tunisia.

The essential-oil composition of 60 individual trees of Juniperus phoenicea L. from four Tunisian populations in three different periods were investigated by GC and GC/MS analyses. 59 Compounds were identified in the oils, and a relatively high variation in their contents was found. All the oils were dominated by the terpenic hydrocarbon fraction, and the main component was alpha-pinene (20.28-40.86%). The results of the oil compositions were processed by hierarchical clustering and principal component analysis (PCA) allowing establishing four groups of essential-oils differentiated by one compound or more. Pattern of geographic variation in essential-oil composition indicated that individuals from the continental site (Makthar) were clearly distinguished from those from littoral localities (Tabarka, Hawaria, and Rimel).