Intraspecific variation in the essential oils from Drimys brasiliensis leaves and stem barks

The essential oils from leaves and stem barks of Drimys brasiliensis Miers (Winteraceae), collected in July and December 2008, were analyzed by GC/FID and GC/MS. The stem bark oils were composed mainly of monoterpenes (July, 45 +/- 3%; December, 92 +/- 4%), while the oils from leaves showed the predominance of sesquiterpenes (July, 47 +/- 1%; December, 55 +/- 1%). The variation in the relative amount of constituents could be associated, at least in part, to several microclimatic parameters such as precipitation, temperature and/or phenological state, which were different for each collection of D. brasiliensis.     

Chemical composition of essential oils from leaves, stems, flower heads and roots of Conyza bonariensis L. from Tunisia

The essential oils isolated at the flowering stage in spring, summer and autumn of the aerial and underground parts of Conyza bonariensis L. growing in Tunisia were analysed by GC and GC/MS; 143 constituents were identified, and among them 20 were major. The oils of C. bonariensis gathered in spring were rich in matricaria ester (1.2-67.3%), (Z)-nerolidol (0.3-19.9%) and caryophyllene oxide (0.8-14.3%). In the summer samples, the oils of C. bonariensis were rich in matricaria ester (1.6-76.4%), caryophyllene oxide (1.6-22.6%) and (E)-β-farnesene (1.1-22.7%). The main constituents in the autumn samples were matricaria ester (trace to 63.5%), geranyl acetone (0.0-25.3%), trans-α-bergamotene (0.0-24.3%) and limonene (2.7-15.3%). The oils showed significant variation among the seasons. Remarkable differences were found between the constituent percentages of the different studied organs. The C. bonariensis sample from Tunisia was a matricaria ester chemotype and was quite different from the samples of other countries of origin.     

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.     

Essential oil composition and acaricidal activity of Schinus terebinthifolius from Atlantic Forest of Pernambuco, Brazil against Tetranychus urticae

The compositions of the essential oils from unripe (UFr) and ripe (RFr) fruits of Schinus terebinthifolius were analyzed by GC and GC/MS. The major compound identified in both oils was limonene (UFr = 44.1 +/- 1.3%; RFr = 31.8 +/- 1.2%), followed by alpha-phellandrene (15.7 +/- 0.4%) in the UFr oil and thujene (21.7 +/- 0.9%) in the RFr oil. Repellent and toxicity activities of the two oils were also evaluated, and the results compared with eugenol. The UFr oil was more active in the fumigation tests (LC50 = 1.46 microL/L of air), whereas the RFr oil was more active in the sealed dishes (SD) than open dishes (OD) contact assay (LC50 = 3.04 microL/cm2) and not significantly different from eugenol. Both oils exhibited significant repellent activity comparable with that of eugenol. The results suggest that the repellent activity of these oils in association with its toxicity could be a great advantage for the integrated management of T. urticae.     

Chemical polymorphism of essential oils from populations of Laurus nobilis grown on Tunisia, Algeria and France

The compositions of the essential oils isolated from the aerial parts of tree Mediterranean populations of Laurus nobilis L. collected during the flowering phase on Tunisia, Algeria and France, were studied by GC and GC-MS. The analysis has allowed identifying 54 components. The main components were 1,8-cineole, alpha-terpinyl acetate (10-18.6%), methyl eugenol (10-22.1%), sabinene (1.2-8%), eugenol (1.2-11.7%) alpha-pinene (tr-4.5%) and beta-pinene (0.4-4.2%). The monoterpene fraction was dominant in all the oils analysed and consisted mainly of oxygenated monoterpenes. The oils from the tree populations studied showed a clear chemical polymorphism. The principal component and the hierarchical cluster analyses separated the Laurus nobilis leaf essential oils into three groups.     

Chemical markers in Origanum vulgare L. from Kumaon Himalayas: a chemosystematic study

The essential oils of four wild growing Origanum vulgare L. (family Lamiaceae) collected from different locations in Kumaon region (Uttarakhand, India) were analysed by capillary GC and GC/MS. The comparative results of O. vulgare L. collected from four different regions showed differences in the chemical constituents of the essential oils. The oil of O. vulgare L. collected from Dhoulchina and Champawat (chemotype I) shows p-cymene (6.7-9.8%), γ-terpinene (12.4-14.0%), thymol (29.7-35.1%) and carvacrol (12.4-20.9%) as major constituents while the oil from Kilbury and Rushi village (chemotype II) shows linalool (6.7-9.7%), bornyl acetate (12.6-16.8%), β-caryophyllene (10.5-13.8%) and germacrene D (6.3-11.3%) as the major constituents. These features highlight the chemosystematics of this genus.     

Citrus essential oil of Nigeria. Part V: Volatile constituents of sweet orange leaf oil (Citrus sinensis)

The volatile oils extracted from leaves of eight cultivars of Citrus sinensis (L) Osbeck were comprehensively analysed by a combination of GC and GC-MS. Fifty four constituents accounting for 82.3-98.2% were identified. Sabinene (20.9-49.1%), delta-3-carene (0.3-14.3%), (E)-beta-ocimene (4.4-12.6%), linalool (3.7-11.1%) and terpinen-4-ol (1.7-12.5%) were the major constituents that are common to all the volatile oils. In addition, a cluster analysis was carried out and indicated at least four different chemotypes for the C. sinensis cultivars.     

The leaf essential oils of five Vietnamese Desmos species (Annonaceae)

The leaf essential oils of five Desmos species from Vietnam have been extracted by steam distillation and subjected to GC and GC-MS analyses. The plant samples were Desmos cochinchinensis Lour., D. penduculosus (A. DC.) Ban, D. penducolosus var. tonkinensis Ban, D. chinensis Lour., and D. dumosus (Roxb.) Saff. The oils were rich in sesquiterpene hydrocarbons (65.9%-88.9%) and monoterpene hydrocarbons (6.3%-30.9%). The oxygenated counterparts were less common. The quantitatively significant constituents of the oils were alpha-pinene (2.4%-12.1%), beta-elemene (2.2-39.5%), beta-caryophyllene (13.9-26.3%), germacrene D (9.9-15.5%), bicyclogermacrene (2.0-11.4%) and alpha-humulene (3.8-7.5%). The studied oils could be classified into two chemical forms: oils with abundance of beta-caryophyllene, germacrene D and alpha-pinene (D. cochinchinensis, D. penducolosus var. tonkinensis, D. chinensis and D. Dumosus) and oil with high amounts of beta-elemene, beta-caryophyllene and germacrene D (D. penduculosus).     

Acaricidal activity against Tetranychus urticae and essential oil composition of four Croton species from Caatinga biome in northeastern Brazil

Volatile components of essential oils from the leaves and stems of Croton jacobinensis, C. rhamnifolius, C. muscicapa and C. micans, which are medicinal plants found in the Caatinga biome of northeastern Brazil, were analyzed using GC and GC/MS. The acaricidal activity of these oils against Tetranychus urticae was evaluated using the fumigation method. Oil yields from the Croton species ranged from 1.1 +/- 0.0 to 0.6 +/- 0.0%, w/w, for leaves and 0.7 +/- 0.0 to 0.1 +/- 0.0% for stems. Sesquiterpenoids were dominant in all oils, except the stem oil from C. rhamnifolius, which exhibited a high monoterpene content, and the leaf and stem oils from C. muscicapa, which were rich in phenylpropanoids. The major volatile components of the leaf and stem oils from C. jacobinensis were (Z)-alpha-atlantone (24.3 +/- 0.4%) and trans-isolongifolanone (22.8 +/- 0.5%), respectively. The most abundant constituents detected in C. rhamnifolius were alpha-cedrene epoxide (23.3 +/- 0.1%) and caryophyllene oxide (21.9 +/- 0.0%) in the leaf oil, and camphor (16.6 +/- 0.5%) and tricyclene (12.8 +/- 0.1%) in the stem oil. Foenicolin was the main compound identified in the leaf (50.6 +/- 0.2%) and stem (72.7 +/- 0.6%) oils of C. muscicapa, while alpha-bulnesene (32.9 +/- 0.2%) and guaiol (17.9 +/- 0.7%) were the principal components of C. micans oils. These oils exhibited a high degree of toxicity in the fumigation assay. The stem oils from C. jacobinensis and C. rhamnifolius exhibited high lethality rates, with LC50 values of 0.3 and 0.2 microL/L of air after 24 h, respectively. The results suggest the potential use of stem essential oil, especially from C. rhamnifolius and C. jacobinensis, for the integrated control of Tetranychus urticae.     

Analysis by gas chromatography-mass spectrometry of the volatile components of Teucrium lusitanicum and Teucrium algarbiensis

The essential oils from four samples of Teucrium lusitanicum and one sample of Teucrium algarbiensis, grown in Algarve (southern Portugal) were analyzed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). Seventy-one volatile compounds were identified. Major compounds of T. algarbiensis oil were alpha-pinene (8.3%), sabinene (7.2%), beta-pinene (10.2%), limonene (11.8%) and germacrene D (7.6%). Concerning T. lusitanicum, some quantitative differences were found with regards to the major constituents of the oils from four populations: alpha-pinene (0.8-8.5%), sabinene (2.1-9.6%), beta-pinene (2.5-11.9%), limonene (1.2-11.5%) and elemol (2.6-12.0%).     

Chemical composition and antibacterial activity of essential oils from leaves, stems and flowers of Salvia reuterana Boiss. grown in Iran

The essential oils obtained by hydrodistillation of the leaves, stems and flowers of Salvia reuterana (Lamiaceae) were analysed by GC and GC/MS. Germacrene D and beta-caryophyllene were the major constituents in all the three oils: (28.5, 27.7 and 32.5%) and (15.5, 11.4 and 16.6%), respectively. Bicyclogermacrene (10.2 and 13.2%) was also prodominated in the stem and flower oils. The composition of the oils was mostly quantitativel rather than qualitatively different. All the oils consisted mainly of sesquiterpenes and a small percentage of non-terpenoid compounds. In all the three oils, monoterpenes were in a concentration less than 0.5%. Antibacterial activity was determined by the measurement of growth inhibitory zones.     

Antiphytoviral activity of sesquiterpene-rich essential oils from four croatian teucrium species

The purpose of this study was to compare the essential oil profiles of four Croatian Teucrium species (Lamiaceae), as determined by GC and GC/MS, with their antiphytoviral efficiency. A phytochemical analysis showed that T. polium, T. flavum, T. montanum and T. chamaedrys are characterized by similar essential oil compositions. The investigated oils are characterized by a high proportion of the sesquiterpene hydrocarbons β-caryophyllene (7.1-52.0%) and germacrene D (8.7-17.0%). Other important components were β-pinene from T. montanum and α-pinene from T. flavum. The investigated essential oils were proved to reduce lesion number in the local host Chenopodium quinoa Willd. infected with Cucumber Mosaic Virus (CMV), with reductions of 41.4%, 22.9%, 44.3% and 25.7%, respectively.     

Chemical composition and antioxidant, antimicrobial, and larvicidal activities of the essential oils of Annona salzmannii and A. pickelii (Annonaceae)

The essential oils from the leaves of Annona salzmannii and A. pickelii (Annonaceae) growing in Sergipe, northeastern region of Brazil, were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS and GC/FID. Thirty-four compounds were identified in the essential oil of A. salzmannii and twenty-seven in that of A. pickelii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (20.3%), (E)-caryophyllene (19.9%), delta-cadinene (15.3%), alpha-copaene (10.0%), and allo-aromadendrene (5.7%) were the main components of A. salzmannii, and bicyclogermacrene (45.4%), (E)-caryophyllene (14.6%), and alpha-copaene (10.6%) of A. pickelii. The essential oils showed significant antioxidant capacity in the ORAC(FL) and DPPH assays. The antimicrobial activity of these essential oils was also evaluated against bacteria and fungi, as well as the larvicidal activity against Aedes aegypti larvae.     

The effect of harvest periods on the chemical compositions of essential oils of sage (Salvia aucheri L.) leaves

The essential oils of sage leaves (Salvia aucheri Bentham var. canescens Boiss. & Heldr.), growing wild in South Anatolia, were extracted by hydrodistillation and analysed by GC and GC-MS. The percentage yields of the essential oils from sage leaves harvested at different years were 1.0%, 1.3%, 1.3%, 1.0%, 1.4%, 1.5% and 1.2%, respectively. In this study, 1,8-cineole, camphre, camphene α-pinene and β-pinene were identified as the major components of sage leaves collected at different periods. The main constituents of sage oil collected over the years were 1,8-cineole (35.01-48.06%), camphre (13.58-23.92%), camphene (6.77-8.82%), α-pinene (5.79-8.54%) and β-pinene (4.32-6.28%).     

Essential oil composition of Prasium majus from Croatia

The essential oils from the aerial parts of Prasium majus L., collected during two years in Croatia, were analysed by GC and GC/MS. Fifty-two compounds were identified, representing 90.3-91.8% of the total oils. The major constituents in both samples were fatty acids (particularly hexadecanoic acid and (Z)-octadec-9-enoic acid), lower aliphatic alcohols, aldehydes and acids (major ones oct-1-en-3-ol and (E,E)-hepta-2,4-dienal) and phenylpropane derivatives (e.g. eugenol). Beta-Caryophyllene was the most abundant terpene and (E)-beta-ionone was the major norisoprenoid.     

Antibacterial activity and GC/MS analysis of the essential oils from flower, leaf and stem of Origanum vulgare ssp. viride growing wild in north-west Iran

Essential oils obtained from flowers, leaves and stems of Origanum vulgare L. ssp. viride (Boiss.) Hayek., growing wild in Ardabil Province (north-west Iran), were analyzed by GC and GC/MS. beta-Caryophyllene was the major constituent in all three oils (48.1%, 50.1% and 60.2%, respectively). Of the 19 components detected in the flower oil, comprising 96.3% of the total, the major components were 1,8-cineole (11.6%), alpha-pinene (6.9%), and gamma-cadinene (4.8%). 1-Octen-3-ol (23.8%), and 1,8-cineole (8.5%) predominated in the leafoil. In the stem oil, other main constituents were bicyclogermacrene (9.8%), 1,8-cineole (6.4%), borneol (5.1%), and pinocarvone (4.4%). The essential oils were evaluated for their antibacterial activity against 10 selected microorganisms. The data obtained contribute to the future use of certain essential oils as natural preservatives for food products, due to their safety and positive effect on shelf life.     

Phytochemical analysis and in vitro antimicrobial and free-radical-scavenging activities of the essential oils from Euryops arabicus and Laggera decurrens

The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the identification of 48 and 44 compounds for both plants, respectively. The essential oil of E. arabicus was rich in oxygenated sesquiterpenes (39.9%). The oil also contained a high content of sesquiterpene hydrocarbons (24.1%). Compounds such as caryophyllene oxide (8.6%), T-cadinol (7.0%), spathulenol (5.2%), (E)-β-caryophyllene (6.0%) and 2-epi-(E)-β-caryophyllene (6.0%) were the main constituents of the oil. Oxygenated monoterpenes also predominated in L. decurrens (46.3%). The thymoquinone-derivative, 3-methoxy-2-methyl-5-(1-methylethyl)-2,5-cyclohexadiene-1,4-dione (28.1%), thymol (5.7%) and eudesma-11-en-4a-ol (7.0%) were the most abundant constituents. Both essential oils showed antimicrobial activity with MIC-values between 0.13-5.25 mg/mL. Furthermore, only the essential oil of L. decurrens exhibited a strong antioxidant activity (91%) at 500 μg/mL.     

Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India

The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC-MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9-95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4-41.8%) was the main compound, followed by eugenyl acetate (0.0-47.1%) and α-phellandrene (0.6-2.5%) in the analysed oils.     

Chemical composition and antimicrobial activity of essential oils from Centaurea pannonica and C. jacea

The chemical composition and antimicrobial activity of the essential oils obtained by hydrodistillation from Centaurea pannonica (Heufel) Simonkai and C. jacea L. (Asteraceae), were investigated. The essential oils were analyzed by GC and GC-MS. Forty five and twenty nine compounds were identified in the two oils, respectively. C. pannonica oil was rich in fatty acids (43.7%), with 9-octadecanoic acid (34.0%) and (Z,Z)-9,12-octadecadienoic acid (8.6%) as the major compounds. In contrast, the essential oil of C. jacea was dominated by oxygenated sesquiterpenes (43.2%), among which caryophyllene oxide (23.5%) and spathulenol (8.9%) were the major constituents. However, the oil was also characterized by an important fatty acid fraction (15.5%), with 9-octadecanoic acid (8.9%) and hexadecanoic acid (6.6%) being the main components. The antimicrobial activities of the essential oils were evaluated by the microdilution method against three Gram-positive and three Gram-negative bacteria, and one yeast. Both oils exhibited significant antimicrobial activity, especially against Gram-positive bacteria.     

Antibacterial activity and comparison of the volatile constituents obtained by several extraction methods from the flowers, stems and leaves of Astrodaucus orientalis

The oils of the flowers, stems and leaves of Astrodaucus orientalis L. were separately extracted using hydrodistillation (HD), head-space solid-phase microextraction (HS-SPME) and microwave assisted head-space solid-phase microextraction (MA-HS-SPME). The volatile constituents were analyzed by GC and GC/MS. Temperature and time of extraction, microwave power and exposure time of extraction were optimized. Polydimethylsiloxane (PDMS) fiber was used as the solid phase for SPME methods. The main constituents of the flower, stem and leaf oils isolated by HD, HS-SPME and MA-HS-SPME are as follows, respectively: beta-pinene (20.5%, 13.9% and 30.4%), alpha-thujene (8.7%, 16.2% and 10.9%) and alpha-pinene (7.6%, 14.3% and 10.9%) for the flowers, sabinene (11.8%, 32.3% and 11.8%), alpha-pinene (8.7%, 28.8% and 6.1%) and p-mycrene (2.5%, 12% and 8.5%) for the stem, and alpha-pinene (9.4%, 37.1% and 22.5%), sabinene (13.5%, 26.3% and 23.5%), beta-pinene (6.3%, 9.8% and 10%) and p-mycrene (3.2%, 2.5% and 15.6%) for the leaf. The minimum inhibitory concentrations (MIC) were determined for all essential oils obtained by HD against both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria using the agar dilution method. These oils showed the good activities against the both bacteria (0.5 - 1.5 mg/mL).