Essential oil composition and antioxidant activity of Stachys sylvatica L. (Lamiaceae) from different wild populations in Kosovo

Leaves and inflorescences of Stachys sylvatica L. (Lamiaceae) were collected from three different wild populations in Kosovo to study the natural variation of the chemical composition of essential oils, total flavonoids, total phenolics and the antioxidant activity. Essential oils were obtained by steam distillation and analysed by GC-FID and GC-MS, whereas total flavonoids, total phenolics and antioxidant activities were determined by spectrophotometric methods. Yields of essential oils ranged from 0.001% to 0.007% (v per dry weight). Twenty-eight volatile constituents were identified. The main constituents were α-pinene, β-pinene and germacrene-D. Total phenolics ranged from 39.3 to 70.8?mg?g?1 dry mass, whereas total flavonoid content ranged from 30.44 to 70.63?mg?g?1 dm. The antioxidant activity, as measured by the DPPH method, exhibited a rather high degree of activity ranging from 25.5% to 57.2%, whereas the FRAP antioxidant activity showed a lower variability and ranged from 93 to 133.4?mg?g?1 dm.     

Chemical composition of volatile and fixed oils from of Salvia argentea L. (Lamiaceae) growing wild in Sicily

The chemical compositions of the essential oil and of the non-polar extracts (petroleum ether, dichloromethane) of the aerial parts (flowers, leaves and stems) of Salvia argentea L. were determined by GC-FID and gas chromatography–mass spectrometry analysis. 14-Hydroxy-α-humulene (40.1%) was recognised as the main constituents of the essential oil of S. argentea, together with 1,3,8-p-menthatriene (12.1%), globulol (7.4%) and β-sesquiphellandrene (5.8%). Tritriacontane (9.9% and 14.1%), heptacosane (8.4% and 10.5%), hentriacontane (8.3% and 10.9%), tetradecanal (8.4% and 10.2%) and methyldotriacontane (7.9% and 7.6%) were recognised as the main constituents of the extracts in petroleum ether and dichloromethane, respectively, whereas methyl linolenate (36.6% and 13.5%) and methyl myristoleate (10.5% and 18.5%) were recognised as the main constituents of the methylated extracts.     

Fast gas chromatography characterisation of purified semiochemicals from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae)

The chemical composition of Matricaria chamomilla L. and Nepeta cataria L. essential oils was determined by GC-MS on an apolar stationary phase by comparison of the characteristic fragmentation patterns with those of the Wiley 275L database. The GC-MS chromatograms were compared with those obtained by fast GC equipped with a direct resistively heated column (Ultra Fast Module 5% phenyl, 5 mx 0.1 mm, 0.1 microm film thickness). Analytical conditions were optimised to reach a good peak resolution (split ratio=1:100), with analysis time lower than 5 min versus 35-45 min required by conventional GC-MS. The fast chromatographic method was completely validated for the analysis of mono- and sesquiterpene compounds. Essential oils were then fractionated by column chromatography packed with silica gel. Three main fractions with high degree of purity in E-beta-farnesene were isolated from the oil of M. chamomilla. One fraction enriched in (Z,E)-nepetalactone and one enriched in beta-caryophyllene were obtained from the oil of N. cataria. These semiochemical compounds could act as attractants of aphid's predators and parasitoids.     

Chemical composition and biological assays of essential oils of Calamintha nepeta (L.) Savi subsp. nepeta (Lamiaceae)

Aerial parts of wild Calamintha nepeta (L.) Savi subsp. nepeta growing spontaneously on the Mediterranean coast (Sardinia Island, Italy) and on the Atlantic coast (Portugal) were used as a matrix for the supercritical extraction of volatile oil with CO(2). The collected extracts were analysed by GC-FID and GC-MS methods and their compositions were compared with that of the essential oil isolated by hydrodistillation, but the differences were not relevant. A strong chemical variability was observed in the essential oils depending on the origin of the samples. The results showed the presence of two chemotypes of C. nepeta. In all Italian samples, pulegone, piperitenone oxide and piperitenone were the main components (64.4-39.9%; 2.5-19.1%; 6.4-7.7%); conversely, the oil extracted from Portuguese C. nepeta is predominantly composed of isomenthone (35.8-51.3%), 1,8-cineole (21.1-21.4%) and trans-isopulegone (7.8-6.0%). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, Candida tropicalis, Candida krusei, Candida guillermondii, Candida parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus. The Italian oil, rich in pulegone, exhibited significant antifungal activity against Aspergillus and dermatophyte strains, with MIC values of 0.32-1.25 μL mL(-1).     

Phytochemical analysis of Saponaria officinalis L. shoots and flowers essential oils

Phytochemical analysis by GC and GC/MS of the essential oil samples obtained from fresh shoots and flowers of Saponaria officinalis L. allowed the identification of 96 components in total, comprising 94.7% and 86.0% of the total oils compositions, respectively. Regarding the shoots essential oil, the major of 87 identified volatile compounds were phytol (14.1%), tricosane-6,8-dione (13.4%), patchouli alcohol (7.9%) and tricosane (7.2%), whereas patchouli alcohol (20.0%), heneicosane (11.5%) and tricosane (8.4%) were dominant among the 66 volatiles in the flower oil. Nonterpenoid compounds had the highest contribution in S. officinalis shoots essential oil (53.7%), while in the flower oil, constituents were almost evenly distributed between the oxygenated sesquiterpenoid (41.2%) and nonterpenoid compounds (39.5%).     

Guaianolides from Salvia nubicola (Lamiaceae)

A new sesquiterpene-lactone (nubenolide) belonging to the guaianolide class along with its acetate (nubenolide acetate) and a dimer (bisnubenolide) have been isolated from Salvia nubicola collected from Quetta, Pakistan. Structures of all three new metabolites were elucidated with the aid of spectroscopic techniques including 2D-NMR. However, the structure of nubenolide was finally confirmed via single-crystal X-ray diffraction method.     

Chemical variability of essential oils in natural populations of Cupressus dupreziana

Essential oils extracted from dried leaves of Cupressus dupreziana A. Camus, an endemic species in the Tassili n'Ajjer (Central Sahara of Algeria), were analyzed by gas chomatography coupled to mass spectrometry (GC-MS). Analyses were carried out on 164 trees of 26 natural populations in order to determine the intra-specific variability. Thirty-two terpenoids were identified, the major ones being alpha-pinene (11.5-44.2), delta3-carene (5.7-31.7) and germacrene-D (15.7-54.1). The terpenoid markers used made it possible to determine the individual patterns of chemotypic variability. This variability confirmed that genetic factors were not responsible for the decrease in the number of this species, the main reason probably being the Tassili n'Ajjer desertification.     

Chemistry and biological activity of essential oils from Piper claussenianum (Piperaceae)

Analyses of essential oils obtained from fresh and dried leaves and inflorescences of Piper clausenianum were performed using GC-FID, GC-MS and NMR techniques. Forty compounds were detected for these four oils with the total of identified constituents ranging from 88.7% for the dried inflorescences to 97.7% for the dried leaves. Sesquiterpenes were the main constituents in the volatile fraction from leaves with a high percentage of (E)-nerolidol (up to 83%). However, monoterpenes were identified in greater amount in the inflorescences, with linalool percentages from 50% up. The essential oils from fresh leaves and inflorescences were submitted to anti-parasitic activity against a strain of Leishmania amazonensis. Both samples showed biological activity, but the essential oil from P. claussenianum fresh leaves, which was rich in (E)-nerolidol, showed effective growth inhibition of L. amazonensis due to the high percentage of this metabolite in the mixture.     

Comparison of the essential oils of leaves and stem bark from two different populations of Drimys winteri a Chilean herbal medicine

The chemical composition of the essential oils obtained by hydrodistillation of stem bark and leaves of Drimys winteri J.R. et G. Foster var. chilensis /DC A. Gray (Winteraceae) from Chiloe Island (ID) and Continental Chile (Santiago) (CD) were studied by GC and GC/MS. Sesquiterpene hydrocarbons constituted the main chemical groups in the stem bark oils, with alpha-santalene, trans-beta-bergamotene and curcumenes as the major components. Monoterpenes constituted the main chemical groups in the leaves of Island plants with alpha-pinene (23.1%) beta-pinene (43.6%) and linalool (10.5%) as the main components whereas sesquiterpenes (germacrene D 17.6%) and phenylpropanoids (safrole 20.8%) are the most abundant in the leaves of Continental plants.     

Study of quantitative and qualitative variations in essential oils of Sicilian Rosmarinus officinalis L.

In this study the chemical characterisation of 10 Sicilian Rosmarinus officinalis L. biotypes essential oils is reported. The main goal of this work was to analyse the relationship between the essential oils yield and the geographical distribution of the species plants. The essential oils were analysed by GC-FID and GC-MS. Hierarchical cluster analysis and principal component analysis statistical methods were used to cluster biotypes according to the essential oils chemical composition. The essential oil yield ranged from 0.8 to 2.3 (v/w). In total 82 compounds have been identified, these represent 96.7–99.9% of the essential oil. The most represented compounds in the essential oils were 1.8-cineole, linalool, α-terpineol, verbenone, α-pinene, limonene, bornyl acetate and terpinolene. The results show that the essential oil yield of the 10 biotypes is affected by the environmental characteristics of the sampling sites while the chemical composition is linked to the genetic characteristics of different biotypes.     

Chemical composition,antimicrobial and antioxidant activities of the essential oils of three Uzbek Lamiaceae species

The chemical composition of the essential oil from the aerial parts of three Lamiaceae species from Uzbekistan was investigated by GC-MS analysis. β-Linalool (26.6%), α-terpineol (10.0%), coumarin (8.9%) and 4,5,7,7α-tetrahydro-4,4,7α-trimethyl-2(6H)-benzofuranone (5.4%) resulted as the main components of Ajuga turkestanica essential oil, while camphene (17.1%), 1,8-cineole (15.9%), β-cymene (7.9%) and limonene (7.4%) in Phlomis regelii. The essential oil of Thymus seravschanicus was dominated by thymol (37.5%), phellandral (26.0%), τ-terpinene (6.6%) and β-cymene (5.2%). The essential oils had considerable antimicrobial activity against different bacterial strains and fungi. Among the tested samples of essential oils, P. regelii essential oil has the significant antioxidant activity with IC₅₀ value of 117.8 ± 8.02 μg/mL.     

New Glycosides from Salvia moorcroftiana (Lamiaceae)

From the MeOH extract of Salvia moorcroftiana Wall. (Lamiaceae), four new compounds, the two flavonoid glycosides genkwanin 4′‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐galactopyranoside] ( 1 ) and genkwanin 4′‐[O‐α‐L ‐arabinopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside] ( 2 ), and the two benzene derivatives 4‐hydroxy‐2‐isopropyl‐5‐methylphenyl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranoside ( 3 ) and nonyl 4‐hydroxybenzoate ( 4 ), were isolated in addition to two known compounds. The structures of all new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy and by comparison with published data.     

Influence of viral infection on essential oil composition of Ocimum basilicum (Lamiaceae)

Ocimum basilicum L., popularly known as sweet basil, is a Lamiaceae species whose essential oil is mainly composed of monoterpenes, sesquiterpenes and phenylpropanoids. The contents of these compounds can be affected by abiotic and biotic factors such as infections caused by viruses. The main goal of this research was an investigation of the effects of viral infection on the essential oil profile of common basil. Seeds of O. basilicum L. cv. Genovese were sowed and kept in a greenhouse. Plants presenting two pairs of leaves above the cotyledons were inoculated with an unidentified virus isolated from a field plant showing chlorotic yellow spots and foliar deformation. Essential oils of healthy and infected plants were extracted by hydrodistillation and analyzed by GCMS. Changes in essential oil composition due to viral infection were observed. Methyleugenol and p-cresol,2,6-di-tert-butyl were the main constituents. However, methyleugenol contents were significantly decreased in infected plants.     

Composition of the essential oils from Anthriscus cerefolium var. trichocarpa and A. caucalis growing wild in the urban area of Vienna (Austria)

The composition of the essential oil from the different above ground plant parts of Anthriscus cerefolium and A. caucalis collected in the urban area of Vienna has been studied. The essential oils of A. cerefolium were dominated by estragole (= methylchavicol) and 1-allyl-2,4-dimethoxybenzene, occurring in various proportions. The oils from young flowering plants had more estragole than 1-allyl-2,4-dimethoxybenzene. Fruits from one location reached 95% estragole in the essential oil. In A. caucalis, the main compound of all oils was cis-chrysanthenyl acetate (up to 74%) followed by cis-chrysanthenol (up to 16%). The fruit oils displayed a higher proportion of cis-chrysanthenyl acetate than the leaf or stem oils.     

Antimicrobial and antioxidant activities of essential oils of Satureja thymbra growing wild in Libya

The composition of essential oil isolated from Satureja thymbra, growing wild in Libya, was analyzed by GC and GC-MS. The essential oil was characterized by γ-terpinene (39.23%), thymol (25.16%), p-cymene (7.17%) and carvacrol (4.18%) as the major constituents. Antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. It possessed strong antioxidant activity (IC50 = 0.0967 mg/mL). The essential oil was also screened for its antimicrobial activity against eight bacterial and eight fungal species, showing excellent antimicrobial activity against the microorganisms used, in particular against the fungi. The oil of S. thymbra showed bacteriostatic activity at 0.001-0.1 mg/mL and was bactericidal at 0.002-0.2 mg/mL; fungistatic effects at 0.001-0.025 mg/mL and fungicidal effects at 0.001-0.1 mg/mL. The main constituents thymol, carvacrol and γ-terpinene also showed strong antimicrobial activity. The commercial fungicide bifonazole showed much lower antifungal activity than the tested oil.     

Chemical composition of the essential oil of Moluccella spinosa L. (Lamiaceae) collected wild in Sicily and its activity on microorganisms affecting historical textiles

In this study the chemical composition of the essential oil from aerial parts of Moluccella spinosa L. collected in Sicily was evaluated by GC and GC-MS. The main components of M. spinosa L. were α-pinene (26.6%), caryophyllene oxide (16.8%) and β-caryophyllene (8.6%). A comparison with other studied oils of genus Moluccella is made. Antibacterial and antifungal activities against some microorganisms infesting historical textiles were also determined.     

Effect of bioclimatic area on the composition and bioactivity of Tunisian Rosmarinus officinalis essential oils

The chemical composition of eight Tunisian Rosmarinus officinalis L. populations (A–H) from different bioclimatic areas has been examined by gas chromatography (GC) and GC-mass spectrometry. The essential oils are characterised by high amounts of oxygenated monoterpenes (58.2–71.7%) followed by monoterpene hydrocabons (15.1–26.7%). 1,8-Cineole, camphor, α-pinene and borneol are the main representative components. The antioxidant activity was investigated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing ability power assay and β-carotene bleaching test. Samples showed antiradical activity by inhibiting DPPH radical with IC₅₀ values ranging from 375.3 to 592.8 μg mL^? 1 for samples F and A, respectively. Sample A also showed the most promising activity in β-carotene bleaching test (IC₅₀ of 31.9 μg mL^? 1). The essential oils were also screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity. Sample G showed the highest activity against AChE (IC₅₀ of 64.7 μg mL^? 1) while sample D (IC₅₀ of 29.5 μg mL^? 1) exhibited the most potent activity against BChE.