Chemical composition and fungitoxic activity of essential oil of Thuja orientalis L. grown in the north-western Himalaya

The essential oil from fresh leaves of Thuja orientalis L. grown in the north-western Himalaya was isolated by means of hydrodistillation and analyzed by GC and GC/MS. Twenty-two compounds representing 94.0% of the total oil were identified. The leaf oil contained alpha-pinene (29.2%), Delta-3-carene (20.1%), alpha-cedrol (9.8%), caryophyllene (7.5%), alpha-humulene (5.6%), limonene (5.4%), alpha-terpinolene (3.8%) and alpha-terpinyl acetate (3.5%) as major constituents. The essential oil showed antifungal activity against Alternaria alternata in a direct bioautography assay. Two main bioactive compounds named as b1 (Rf = 0.54) and b2 (Rf = 0.80) were observed and tested for antifungal activity; they produced an inhibition zone of 5 and 10 mm in diameter, respectively. The components b1 and b2 were further purified by preparative thin layer chromatography and their antifungal efficacy was re-tested. The minimum inhibitory amount (MIA) of b1 and b2 against A. alternata was determined as 30.5 and 4.5 microg, respectively, using a bioautography assay. The bioactive constituent corresponding to b1 was determined as alpha-cedrol by using GC/MS analysis. The potential of essential oils as a source of natural biocides is discussed.     

Antifungal activity of Juniperus essential oils against dermatophyte, Aspergillus and Candida strains

AIMS: The increasing resistance to antifungal compounds and the reduced number of available drugs led us to search therapeutic alternatives among aromatic plants and their essential oils, empirically used by antifungal proprieties. In this work the authors report on the antifungal activity of Juniperus essential oils (Juniperus communis ssp. alpina, J. oxycedrus ssp. oxycedrus and J. turbinata). METHODS AND RESULTS: Antifungal activity was evaluated by determination of MIC and MLC values, using a macrodilution method (NCCLS protocols), on clinical and type strains of Candida, Aspergillus and dermatophytes. The composition of the oils was ascertained by GC and GC/MS analysis. All essential oils inhibited test dermatophyte strains. The oil from leaves of J. oxycedrus ssp. oxycedrus is the most active, with MIC and MLC values ranging from 0.08-0.16 microl ml(-1) to 0.08-0.32 microl ml(-1), respectively. This oil is mainly composed of alpha-pinene (65.5%) and delta-3-carene (5.7%). CONCLUSIONS: J. oxycedrus ssp. oxycedrus leaf oil proved to be an emergent alternative as antifungal agent against dermatophyte strains. delta-3-Carene, was shown to be a fundamental compound for this activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Results support that essential oils or some of their constituents may be useful in the clinical management of fungal infections, justifying future clinical trials to validate their use as therapeutic alternatives for dermatophytosis.     

Chemical composition and antimicrobial activity of the essential oils of the Amazon Guatteriopsis species

The essential oils of Guatteriopsis blepharophylla, Guatteriopsis friesiana and Guatteriopsis hispida were obtained by hydrodistillation and analysed by GC and GC/MS. The main compound found in the leaf oil of G. blepharophylla was caryophyllene oxide (1) (69.25%). The leaf oil of G. friesiana contained predominantly beta-eudesmol (2) (51.60%), gamma-eudesmol (3) (23.70%), and alpha-eudesmol (4) (14.56%). The major constituents identified in the leaf of G. hispida were beta-pinene (38.18%), alpha-pinene (30.77%) and (E)-caryophyllene (20.59%). The antimicrobial activity of the essential oils was evaluated against 11 species of microorganisms. The oil of G. friesiana exhibited significant antimicrobial activity for all microorganisms tested, whereas that of G. hispida and G. blepharophyla had potent activity against Rhodococcus equi with MIC of 50 microg mL(-1). The major constituents of each oil were also tested separately, and showed lower activity compared to the oils. Moreover, mixtures of the main constituents, in the same proportions found in G. friesiana and G. hispida oils, did not show the same activity as the original oils.     

Antioxidant and Antibacterial Activities of Crude Extracts and Essential Oils of Syzygium cumini Leaves

This research highlights the chemical composition, antioxidant and antibacterial activities of essential oils and various crude extracts (using methanol and methylene chloride) from Syzygium cumini leaves. Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS).The abundant constituents of the oils were: α-pinene (32.32%), β-pinene (12.44%), trans-caryophyllene (11.19%), 1, 3, 6-octatriene (8.41%), delta-3-carene (5.55%), α-caryophyllene (4.36%), and α-limonene (3.42%).The antioxidant activities of all extracts were examined using two complementary methods, namely diphenylpicrylhydrazyl (DPPH) and ferric reducing power (FRAP). In both methods, the methanol extract exhibited a higher activity than methylene chloride and essential oil extracts. A higher content of both total phenolics and flavonoids were found in the methanolic extract compared with other extracts. Furthermore, the methanol extract had higher antibacterial activity compared to methylene chloride and the essential oil extracts. Due to their antioxidant and antibacterial properties, the leaf extracts from S. cumini may be used as natural preservative ingredients in food and/or pharmaceutical industries.     

Essential oils from Azorean Laurus azorica

The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC-MS. All oil samples were dominated by their monoterpene fraction (60-94%), alpha-pinene (15-37%) and 1,8-cineole (12-31%) being the main components of the leaf oils, while trans-beta-ocimene (27-45%) and alpha-pinene (12-22%) were the main components of the oils from the berries. The sesquiterpene fractions of the oils ranged from 3 to 17% and the main components were beta-caryophyllene (traces-8%) and beta-elemene (traces-3%) both in the leaf and berry oils. Some phenylpropanoid components were also present, in total amounting to 17%, trans-cinnamyl acetate (215% of the leaf oils) being the main component of this fraction. Cluster analysis of the enantiomeric composition of alpha- and beta-pinene in the oils from the leaves clearly showed two groups, one constituted by the two populations growing on the island S. Jorge, and the other constituted by the remaining populations.     

Effect of rootstock on mango fruit susceptibility to infestation by Anastrepha obliqua

The effect of the use of rootstock Criollo on the susceptibility of Manila mango fruit to infestation by Anastrepha obliqua (Macquart) was determined in the present investigation. Growth, quality parameters (Soluble solids content (%), citric acid content (%), firmness, monoterpene volatiles (3-carene, limonene, alpha-pinene, and beta-myrcene), main flavonoids content (milligrams/100 g fresh pulp), and larvicidal activity of methanolic extracts, as well as the degree of infestation during preharvest development of the fruits were analyzed. The results indicated that the rootstock did not have any significant effect on growth, soluble solids content, or citric acid content; although it increased firmness as well as 3-carene levels and main flavonoids content, resulting in a greater resistance to infestation by A. obliqua. The obtained results support the use of this rootstock because of the beneficial effects observed on the resistance of mango fruit to infestation by this fruit fly.     

Essential oils from micropropagated plants of Lavandula viridis

The essential oils of Lavandula viridis were analysed by GC and GC-MS. Comparisons were made between three types of plant material from the same clone: field-grown plant, in vitro shoot cultures and micropropagated plants of the same clone. The most common components usually found in lavender oils were present in the oil samples analysed and more than 45 constituents were identified, representing more than 80% of the essential oil. The essential oils analysed consisted mainly of monoterpenes (75.4-76.3%), where oxygenated and hydrocarbons identified ranged from 41.8 to 57.3% and 18.1 to 34.2%, respectively. The major components found were 1.8-cineole (18.2-25.1%), camphor (9.1-15.7%), alpha-pinene (8.8-14.1%), borneol (4.1-4.8%), beta-pinene (1.2-5.6%), delta 3-carene (1.0-6.5%) and alpha-terpineol (0.8-4.2%). The monoterpene fraction of the in vitro shoot cultures showed different relative amounts of hydrocarbons and oxygenated components in relation to the parent plant and to micropropagated plants. In the sesquiterpene hydrocarbon fraction of the oil samples analysed (6.1-8.2%), 7-epi-alpha-selinene (1.6-4.8%) was the most important component and the oxygenated sesquiterpenes were found in small amounts (1.1-1.7%). The essential oils from field-grown plants of L. viridis, when compared with those obtained from in vitro shoot cultures or micropropagated plants of the same clone, demonstrated that the same major components were found without significant compositional variations.     

Antifungal activity of the essential oils from some species of the genus Pinus

The chemical composition of the essential oils from the needles of Pinus ponderosa (north american pine), P. resinosa (red pine) and P. strobus (eastern white pine) has been determined by GC/MS (FID). The essential oils from P. resinosa and P. ponderosa in comparison to P. strobus have been characterized by the higher content of beta-pinene (42.4%, 45.7% and 7.9% respectively). On the other hand, a-pinene (17.7%) and germacrene D (12.2%) were dominant compounds of P strobus. Moreover the essential oil from P. resinosa was more rich in myrcene-15.9%. Estragole and delta-3-carene, each one in amount ca 8% were identified only in P. ponderosa. The content of essential oils in the needles slightly varied--0.65%--P. resinosa, 0.4%--P strobus, 0.3%--P. ponderosa. The antifungal activity has been investigated towards Fusarium culmorum, F solani and F. poae. The strongest activity was observed for the essential oil from P. ponderosa, which fully inhibited the growth of fungi at the following concentrations--F. culmorum, F. solani at 2% and F. poae at 5%.     

Intraspecific chemical variability of the leaf essential oil of Juniperus phoenicea subsp. turbinata from Corsica

The composition of 50 samples of essential oil of individual plants of Juniperus phoenicea subsp. turbinata from Corsica was investigated by GC, GC-MS and 13C NMR. alpha-Pinene, beta-phellandrene, alpha-terpinyl acetate, Delta-3-carene, myrcene and alpha-phellandrene were found to be the main constituents. The results were submitted to cluster analysis and discriminant analysis which allowed two groups of essential oils to be distinguished with respect to the content of alpha-pinene, beta-phellandrene and alpha-terpinyl acetate.     

Chemical composition of the essential oils of two Alpinia species from Hainan Island, China

The essential oils of two Alpinia species, ie. A. hainanensis and A. katsumadai, from Hainan Island, China were analyzed by using GC-MS. The major constituents in the leaf oil of A. hainanensis were ocimene (27.4%), beta-pinene (10.1%), 9-octadecenoic acid (6.5%), n-hexadecanoic acid (5.8%), 9,12-octadecadienoic acid (5.4%), and terpinen (4.3%). The oil constituents obtained from the flowers of A. hainanensis were ocimene (39.8%), beta-pinene (17.7%), terpinene (5.5%), p-menth-1-en-ol (4.9%), caryophyllene (4.9%), and phellandrene (4.4%). In A. katsumadai, the major constituents in the leaf oil were p-menth-1-en-ol (22.0%), terpinen (19.0%), 4-carene (9.1%), 1,8-cineole (8.3%), and camphor (5.6%). The major constituents in the flower oil were p-menth-1-en-ol (21.3%), 1,8-cineole (20.2%), terpinen (12.6%), phellandrene (7.0%), 4-carene (6.4%), and beta-pinene (5.2%).     

Volatile constituents of the flower and fruit oils of Pittosporum tobira (Thunb.) Ait. grown in Iran

The volatile components of the flower and fruit oils from Pittosporum tobira (Thunb.) Ait. grown in Iran, obtained through hydrodistillation, were analyzed by GC/MS. Sixteen compounds (representing 90.7% of the oil) and seventeen constituents (representing 89.9% of the oil) were identified in the flower and fruit oils, respectively. While the flower oil contained a-pinene (38.6%), n-nonane (11.8%), (E)-nerolidol (9.0%) and (E)-beta-ocimene (7.7%), the fruit oil contained a-pinene (30.2%), n-nonane (12.2%), germacrene-D (12.0%), a-cubebene (7.6%) and beta-cubebene (5.1%) as the main compounds.     

The steam volatile oil of Wollemia nobilis and its comparison with other members of the Araucariaceae (Agathis and Araucaria)

The leaf essential oil of Wollemia nobilis (Wollemi Pine) has been investigated and compared with other members of the family Araucariaceae. All araucaroids examined yielded steam volatile oils in low yields. The oil from Wollemia nobilis was composed mainly of (+)-16-kaurene (60%), together with alpha-pinene (9%) and germacrene-D (8%). Oils from Agathis species endemic to Australia were high in monoterpenes, in contrast to those isolated from extra-Australian species. The major constituents of A. atropurpurea oil were phyllocladene (13%) and 16-kaurene (19%), followed by alpha-pinene (8%) and delta-cadinene (9%). A. microstachya yielded oil in which alpha-pinene (18%) was the major component; the only other components in excess of 5% were myrcene (7%), bicyclogermacrene (6%) and delta-cadinene (6%). A. robusta oil contained spathulenol (37%) and rimuene (6%). Approximately 40% of the oil was unidentified sesquiterpenes. A. australis oil contained 16-kaurene (37%), sclarene (5%) and an unidentified oxygenated diterpene K (12%) as major components; the only other compound in excess of 5% was germacrene-D (9%). 5,15-Rosadiene (60%), and 16-kaurene (7%) were the major constituents of A. macrophylla oil. A. moorei oil was rich in sesquiterpenes, but the only compounds in excess of 5% were allo-aromadendrene (6%), germacrene-D, delta-cadinene (10%), an unidentified sesquiterpene (12%) and 16-kaurene (6%). In A. ovata oil the most significant compounds were caryophyllene oxide (15%) and phyllocladene (39%). Araucaria angustifolia contained germacrene-D (9%) and the diterpenes hibaene (30%) and phyllocladene (20%) as major components of its essential oil. Oils of A. bidwillii, A. columnaris and A. cunninghamii were all low in mono- and sesquiterpenes and high in diterpenes. In the first, hibaene (76%) was the major constituent; the second contained hibaene (9%), sclarene (6%), luxuriadiene (13-epi-dolabradiene)(23%) and two unidentified diterpene hydrocarbons (B) (33%) and (E) (10%). In the last, 16-kaurene (53%) was the most significant component followed by hibaene (29%). A. heterophylla was unusual in that over half the oil was made up of the monoterpenoid alpha-pinene (52%), with phyllocladene (32%) being the only other compound of significance. alpha-Pinene (18%) was a significant component of A. hunsteinii oil; sclarene (11%) and germacrene-D (5%) were the only other compounds present in concentrations of more than 5%. A. luxurians oil was composed of 5,15-rosadiene (20%) and luxuriadiene (13-epi-dolabradiene) (66%), previously unreported from natural sources. The major components of A. montana were phyllocladene (61%) and 16-kaurene (23%). Sclarene (20%), luxuriadiene (19%) and the unidentified diterpene hydrocarbons (B) (25%) and (E) (10%) were the most important constituents of A. muelleri oil. A. scopulorum contained large amounts of 16-alpha-phyllocladanol (41%) as well as luxuridiene (10%) and delta-cadinene and alpha-copaene, both at 6%.     

Phytochemical Analysis and in vitro Free‐Radical‐Scavenging Activities of the Essential Oils from Leaf and Fruit of Melaleuca leucadendra L.

The phytochemical profile of Melaleuca leucadendra L. leaf and fruit oils from Cuba was investigated by GC and GC/MS. Forty‐one and sixty‐four volatile compounds were identified and quantified, accounting for 99.2 and 99.5% of the leaf‐oil and fruit‐oil total composition, respectively. The main components were 1,8‐cineol (43.0%), viridiflorol (24.2%), α‐terpineol (7.0%), α‐pinene (5.3%), and limonene (4.8%) in the leaf oil, and viridiflorol (47.6%), globulol (5.8%), guaiol (5.3%), and α‐pinene (4.5%) in the fruit oil. The antioxidant capacity of these essential oils was determined by three different in vitro assays (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical, thiobarbituric acid reactive species (TBARS), and 2,2′‐Azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical cation), and significant activities were evidenced for all of them.     

Essential oil of Lepechinia schiedeana (Lamiaceae) from Costa Rica

The composition of the essential oil isolated by steam distillation from aerial parts of the Costa Rican herb Lepechinia schiedeana (Schlecht) Vatke (Lamiaceae) collected in El Empalme, Costa Rica, was determined by capillary gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GC-MS) analyses. Fifty-one components were identified corresponding ca. 93% of the oil. The major components were beta-pinene (26.6%), cis-pinocamphone (25.1%), delta-3-carene (6.1%), trans-pinocamphone (4.0%), camphor (3.8%) and beta-caryophyllene (3.7%).     

Application of multidimensional gas chromatography to the enantioselective characterisation of the essential oil of Eupatorium buniifolium Hooker et Arnott

The qualitative and quantitative composition of the essential oil from aerial parts of Eupatorium buniifolium Hooker et Arnott (Asteraceae) has been investigated for the first time. The essential oils were obtained by steam distillation of leaves and analysed by GC-MS; 44 components were identified. Monoterpene and sesquiterpene hydrocarbons, especially alpha-pinene (14.7%), beta-elemene (12.2%), germacrene D (11.5%), trans-beta-guaiene (6.5%) and (E)-caryophyllene (4.3%), were the major constituents found in the oils. The characterisation of E. buniifolium by enantioselective GC was performed by evaluation of the enantiomeric ratios of alpha-pinene, sabinene, beta-pinene, limonene, terpinen-4-ol and germacrene D.     

Variations in insecticidal activity and chemical compositions of leaf essential oils from Cryptomeria japonica at different ages

The larvicidal effects of the essential oils extracted from the leaves of Cryptomeria japonica at different ages (58, 42, and 26 years old) against 2 mosquito species, Aedes aegypti and Aedes albopictus, were studied. The analysis of major constituents of these essential oils was also investigated. Results obtained from the larvicidal tests, using essential oil from the leaves of 58-year-old C. japonica was found to be most effective against both A. aegypti and A. albopictus larvae, indicating tree age has significant influence on mosquito larvicidal activity. In addition, the eleven pure constituents from C. japonica leaf essential oil were also tested individually against the two mosquito larvae. Among them, alpha-terpinene, gamma-terpinene, p-cymene, 3-carene, terpinolene, and beta-myrcene shows strong larvicidal effect against the two mosquito larvae. Among these pure constituents, 3-carene exhibits the best larvicidal effect against A. aegypti and terpinolene shows an excellent inhibitory action against A. albopictus larvae. The results of this study show that the leaf essential oil and its effective constituents might be considered as a potent source for the production of fine natural larvicides.     

Antimicrobial activity of six constituents of essential oil from Salvia

The antimicrobial activity of three Salvia species, i.e. S. santolinifolia, S. hydrangea and S. mirzayanii, essential oils were investigated. The essential oils were obtained from the aerial parts of plants and analyzed by GC-MS. The main constituents of aforementioned species were alpha-pinene (72.4%), beta-pinene (6.6%) and limonene (5.3%); beta-caryophyllene (25.1%), 1,8-cineol (15.2%) and caryophyllene oxide (11.5%); alpha-terpinenyl acetate (22.6%), 1,8-cineol (21.2%) and linalool (8.9%), respectively. Bioassays exhibited that the property of the oil of S. myrzayanii was superior to others. The antimicrobial activity of essential oil from Salvia species may well be due to the presence of synergy between six tested compounds (linalool, 1,8-cineol, alpha-pinene, beta-pinene, beta-caryophyllene and limonene) and other constituents of the oils with various degrees of antimicrobial activity. Among these, linalool and 1,8-cineol had the highest antimicrobial activity.     

Chemical composition and acaricidal properties of Deverra scoparia essential oil (Araliales: Apiaceae) and blends of its major constituents against Tetranychus urticae (Acari: Tetranychidae)

The essential oil of Deverra scoparia Coss. & Durieu was investigated for its acaricidal activity against the worldwide pest twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). The essential oil was analyzed by fast gas chromatography (GC) and GC-mass spectrometry. The activities of its individual and blended constituents were determined. Our study showed that female mortality increased with increasing D. scoparia oil concentrations, with LD50 and LD90 values at 1.79 and 3.2 mg liter(-1), respectively. A reduction in fecundity had already been observed for concentrations of 0.064, 0.08, and 0.26 mg liter(-1) D. scoparia essential oil. Ten major components, comprising 98.52% of the total weight, were identified; a-pinene was the most abundant constituent (31.95%) followed by sabinene (17.24%) and delta3-carene (16.85%). The 10 major constituents of D. scoparia oil were individually tested against T. urticae females. The most potent toxicity was found with alpha-pinene, delta3-carene, and terpinen-4-ol. The presence of all constituents together in the artificial mixture caused a significant decrease in the number of eggs laid by females, at 0.26 mg liter(-1) (11 eggs), compared with the control (50 eggs). The toxicity of blends of selected constituents indicated that the presence of all constituents was necessary to reproduce the toxicity level of the natural oil.     

Chemical composition and antimicrobial activity of essential oil from cones of Pinus koraiensis

The essential oil from the cones of Pinus koraiensis was prepared after removing the seeds, and its chemical composition analyzed using gas chromatography-mass spectrometry (GC-MS). Hydrodistillation of the P. koraiensis cones yielded 1.07% (v/w) of essential oil, which was almost three times the amount of essential oil extracted from the needles of the same plant. Moreover, the antimicrobial activities of the oil against the growth of Gram-positive bacteria, Gram-negative bacteria, and fungi were evaluated using the agar disc diffusion method and broth microdilution method. Eighty-seven components, comprising about 96.8% of the total oil, were identified. The most abundant oil components were limonene (27.90%), alpha-pinene (23.89%), beta-pinene (12.02%), 3-carene (4.95%), beta-myrcene (4.53%), isolongifolene (3.35%), (-)-bornyl acetate (2.02%), caryophyllene (1.71%), and camphene (1.54%). The essential oil was confirmed to have significant antimicrobial activities, especially against pathogenic fungal strains such as Candida glabrata YFCC 062 and Cryptococcus neoformans B 42419. Therefore, the present results indicate that the essential oil from the cones of Pinus koraiensis can be used in various ways as a nontoxic and environmentally friendly disinfectant.     

Toxicity of some terpenoids of essential oils of Xylopia aethiopica from Cameroon against Sitophilus zeamais Motschulsky

Abstract:  The acute toxicity of essential oils from the whole fruit (EF) or from the fibres of the fruit (FF) of the local aromatic plants Xylopia aethiopica Dunal (Annonaceae) collected in north Cameroon was evaluated on Sitophilus zeamais adults. A concentration of 1 ml of essential oil per 100 g of maize seeds was tested to determine weevil mortality after 24 h of exposure. Under these conditions, the essential oil derived from both EF and FF of X. aethiopica led to 100% mortality. In a second step, proportions of active compounds present in the oil of both EF and FF of X. aethiopica were quantified. The toxicity of the four main compounds was tested against S. zeamais : α -pinene, β -pinene, Δ-3-carene and terpinen-4-ol according to their proportion in the essential oil of the concerned plant part. β -pinene and terpinen-4-ol were responsible for 50% of the mortality at the proportion found in EF and FF essential oils respectively. When mixed, a synergic effect of the compounds was observed that restored the mortality percentage observed for the crude oil. It appears that X. aethiopica essential oil could be a potential source of natural and low-cost insecticide to control storage pests.