Volatile constituents of Zingiber officinale rhizomes produced by in vitro shoot tip culture

Plantlets with rhizomes were produced in vitro from shoot tips of Zingiber officinale grown in both modified Gamborg's B5 (B5) and Murashige-Skoog (MS) media supplemented with various levels of growth regulators. The rhizomes accumulated the volatile oils similar to those formed in the original rhizome. In the oil from the rhizome grown in the modified B5 medium, the acyclic oxygenated monoterpenes predominated, while the oil from the rhizome grown in the modified MS medium consisted mainly of sesquiterpenes.     

Essential oil composition of Hypericum triquetrifolium Turra. aerial parts

The essential oil obtained by hydrodistillation from the aerial parts of Tunisian endemic Hypericum triquetrifolium Turra (Clusiaceae) was analyzed using GC and GC-MS. One hundred and nine compounds consisting of 92.2% of total detected constituents were identified. Sesquiterpene hydrocarbons were the main constituents (59.37%), Alpha-humulene, cis-calamenene, delta-cadinene, bicyclogermacrene, eremophilene, betacaryophyllene and (E)-gamma-bisabolene were found as the main ones. Alpha-pinene (10.33%) was detected as the main monoterpene hydrocarbons (12.19%). The oxygenated sesquiterpenes constituted (9.33%); caryophyllene oxide (1.38%) was reported as the main constituent of this fraction. The oxygenated monoterpenes were weakly represented (4.62%) and consisted of constituents in low percentages (<1%).     

Salvia verbenaca L. essential oil: Variation of yield and composition according to collection site and phenophase

The effect of the collection sites and phenophase on yield and chemical composition of Salvia verbenaca essential oils was evaluated. The essential oil constituents were assessed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The highest essential oil yields were observed for samples of the higher semi-arid bioclimate and at the flowering period. Eighty-five volatile constituents were identified and their percentages varied significantly (p < 0.05) depending on the collection site and the phenological stage. According to the plants origin, essential oils were dominated by monoterpene hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons. The monoterpene hydrocarbons (31.9%) predominate at the flowering stage whereas oxygenated sesquiterpenes (27.5%) at the early fruiting stage. The sesquiterpene hydrocarbons (28.2%) was the most represented chemical class at late fruiting. On the basis of GC-MS data, the major identified volatile constituents were viridiflorol (3.4–17.7%), α-pinene (0.7–15.9%), β-caryophyllene (1.0–15.3%) and p-cymene (1.3–14.2%). S. verbenaca contains a diversity of bioactive constituents which shows large variations as affected by the collection sites and phenophase.     

Chemical composition and antibacterial potential of Artemisia arborescens L. essential oil

This study was undertaken to characterize the essential oil (EO) of Artemisia arborescens growing wild in Sicily. EO, extracted by steam distillation, was examined for its chemical composition and for its capability to inhibit some food-borne pathogen bacteria. A total of 43 compounds (13 monoterpene hydrocarbons, 14 oxygenated monoterpenes, 10 sesquiterpene hydrocarbons, three oxygenated sesquiterpenes and less amount of other three compounds), which account 93.73% of the total oil, were identified by gas chromatography and gas chromatography–mass spectrometry. Oxygenated monoterpenes (57.32%) constituted the main fraction, with β-thujone as the main compound (45.04%), followed by the sesquiterpene hydrocarbon chamazulene (22.71%). Undiluted EO showed a large inhibition spectrum against strains of Listeria monocytogenes (34 out of 44), whilst it was ineffective against enterobacteria and salmonellas. The minimum inhibition concentration (MIC) was evaluated for the two most sensitive strains (L. monocytogenes 186 and 7BO) at two cellular concentrations (10⁶ and 10⁷ CFU ml⁻¹). The lowest MIC (0.625 μl ml⁻¹, dilution of oil with acetone) was found for strain L. monocytogenes 186 at 10⁶ CFU ml⁻¹.     

Volatile Constituents of the Aerial Parts of Pulicaria sicula (L.) Moris Growing Wild in Sicily: Chemotaxonomic Volatile Markers of the Genus Pulicaria Gaertn.

The chemical composition of the essential oil isolated from the aerial parts of Pulicaria sicula (L.) Moris was characterized by GC‐FID and GC/MS analyses. The oil was particularly rich in oxygenated terpenoids. Among the oxygenated monoterpenes (content of 44.5%), the most abundant were borneol (23.7%), bornyl acetate (6.5%), and isothymol isobutyrate (6.2%). Caryophyllene oxide (10.2%), caryophylladienol I (4.3%), and caryophylla‐3,8(13)‐dien‐5β‐ol (4.4%) were identified as the main constituents among the oxygenated sesquiterpenes. Furthermore, a complete literature review on the composition of the essential oils of all the Pulicaria taxa studied so far was performed and a principal component analysis (PCA) was carried out.     

Composition of essential oils from Cupressus lusitanica and a Xylariaceous fungus found on its leaves

A Xylariaceous endophytic fungus was isolated from leaves of Cupressus lusitanica. Essential oil was extracted from these two organisms using the hydrodistillation method and identified by gas chromatography-mass spectrometry and retention index. A variety of monoterpenes, sesquiterpenes and diterpenes were identified in the fungus and the plant, and some of them were co-produced by both organisms. The oil extracted from C. lusitanica was tested against three of the endophytic fungi found in its leaves and showed only slightly antifungal activity.     

Chemical composition of the essential oils of ripe berries of Juniperus oxycedrus L., growing wild in Kosovo

The main objective of this work was to study the essential oil composition of ripe Juniperus oxycedrus L. berries and its natural variation among wild populations in Kosovo. Essential oil was analysed using GC-FID and GC–MS. Plant materials were collected from five locations in Kosovo in August and September of 2011. In total, twenty-seven compounds were identified in the essential oils. The main components were β-myrcene (45.5–56.9%), α-pinene (10.2–36.6%), dl-limonene (3.6–13.8%) and germacrene D (1.7–8.7%). Of the total identified compounds, monoterpenes constituted the highest percentage of all components (70.24–88.22%), followed by oxygenated sesquiterpenes (4.9–11.4%), sesquiterpenes (3.5–11.0%), oxygenated monoterpenes (0.2–2.7%) and oxygenated diterpenes (0.0–1.7). Hierarchical Cluster Analysis (HCA) and Principal Component Analyses (PCA) were used to identify any geographical variations in essential oil composition. Statistical analysis suggests that the clustering of populations is not related to their geographic location, but rather seemed to be linked to local selective forces acting on chemotype diversity.     

Antifungal Activity of the Essential Oils of Callitris neocaledonica and C. sulcata Heartwood (Cupressaceae)

Mortality due to fungal infections has increased substantially, becoming a worldwide problem in public health. As a contribution to the discovery of new antifungal agents, the properties of the heartwood essential oils of two trees growing in New Caledonia, Callitris neocaledonica and C. sulcata (Cupressaceae) were investigated. The essential oils extracted by hydrodistillation were characterized by GC-FID and GC/MS analyses. From C. neocaledonica oil, 31 constituents were identified, representing 97.0% of the total oil composition, which was mainly constituted by oxygenated sesquiterpenes (88%). Among them, guaiol (1; 30.2%), bulnesol (2; 12.5%), α-eudesmol (3; 10.5%), β-eudesmol (4; 10.5%), γ-eudesmol (10.2%), and elemol (4.9%) predominated. The chemical composition of C. sulcata oil, from which 39 constituents were identified (96.8% of the total oil composition), showed some similarities with that of C. neocaledonica oil. The major constituents were also oxygenated sesquiterpenes, accounting for 78.5% of the oil, amongst them, mainly compounds 1 (16.1%), 3 and 4 (9.7% each), as well as 2 (7.4%). The antifungal activity of the oils against clinical isolates of four dermatophytic fungi (Trichophyton mentagrophytes, T. rubrum, Microsporum canis, and M. gypseum) and six yeasts (Candida albicans, C. parapsilosis, C. glabrata, C. krusei, Cryptococcus neoformans, and Cryptococcus gattii) was tested by determining minimum inhibitory concentrations (MICs) using the microdilution method. The best antifungal activities of the C. neocaledonica and C. sulcata oils were obtained against C. krusei (MICs of 3.9 and 0.975?μg/ml, resp.). These MIC values were similar to those of the reference drugs itraconazole and fluconazole (1.0 and 0.5?mg/ml, resp.). The oils were also subjected to a screening for their possible DPPH(.) (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity. C. neocaledonica essential oil was more active than C. sulcata oil (93.3 vs. 32.2% DPPH(.) scavenged at 250?μg/ml).     

A chemometric interpopulation study of the essential oils of Cistus creticus L. growing in Crete (Greece)

The chemical composition of the essential oils of twenty-five populations of Cistus creticus subsp. creticus L. from the island of Crete (Greece) and their interpopulation variability were analysed in detail by GC-MS. 142 compounds were identified representing an average of 56.8-89.8% of the oil composition. The components are represented here by homologous series of monoterpenes, oxygenated monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, diterpenes, labdane diterpenes, aldehydes, alkanes, esters, fatty acids, ketones, and others. Labdane diterpenes were detected and identified in the essential oils and have been found in high percentage composition. The results from the chemical analysis of the essential oils were submitted to chemometric cluster analysis in order to detect some pattern distribution and to identify which constituents can differentiate the groups of individuals. Two main chemotypes (clusters) were well differentiated; the first deals with eight populations of West Crete and the second with the rest of the populations. Cluster analysis based on labdane type diterpenes patterns, proved to be the best chemotype for the examined populations among the other chemical groups.     

Essential oil yield,composition, bioactivity and leaf morphology of Juniperus oxycedrus L. from Bulgaria and Serbia

Juniperus oxycedrus L. (Cupressaceae Bartlett) is widely distributed in countries with a Mediterranean climate. All plant parts contain highly aromatic essential oil (EO) and recently there have been efforts to introduce it as a cultivated crop. The species is known for its large morphological and chemical variation and its debatable taxonomic status. This study aimed to (1) compare content, composition, and antimicrobial activity of J. oxycedrus EO samples from plants growing in Bulgaria and Serbia, and (2) quantify morphological variations of leaves. Тhe EO content (yield) in dried juniper leaves varied from 0.06% (Кopaonik, Serbia) to 0.24% (Markovo, Bulgaria). We identified 51 EO constituents, belonging to monoterpenes, sesquiterpenes, and diterpenes. The class monoterpenes (monoterpene hydrocarbons and oxygenated monoterpenes) were the predominant compounds, representing 38.6–65.4% of the total EO, consisting primarily of α-pinene, limonene, sabinene, β-pinene, and β-myrcene. In addition, α-pinene was the major oil constituent in plants from all locations. Sesquiterpenes (sesquiterpene hydrocarbons and oxygenated sesquiterpenes) were the second largest class of constituents, which represented 19.3% tо 33.6% of the total EO. γ-Elemene was found only in the EO of J. oxycedrus from Bulgaria, while a high concentration of α-curcumene was found only in samples from Serbia (7.5–7.8%). Significant differences in antimicrobial activity of the EO were found in bacterial strains Bacillus cereus and Streptococcus pneumoniae. There was no significant difference among the mean leaf width of the six combinations location x sex, and the overall leaf mean width was 1.24 mm. However, there was a significant difference between the mean leaf lengths. In this study, none of the studied populations had a higher concentration of limonene than of α-pinene, indicating that the flora of the two countries include J. oxycedrus and not the previously reported J. deltoides. The results revealed significant variation in EO profile that may contribute to the development of new cultivars of J. oxycedrus.     

Antimicrobial and insecticidal activities of essential oil isolated from Turkish Salvia hydrangea DC. ex Benth.

The hydrodistillated essential oil of Salvia hydrangea was analyzed by GC–MS. Fifty-four different components representing 95.9% of the compounds in the oil were identified. Camphor (54.2%), -humulene (4.0%), cis-sesquisabinene hydrate (2.8%), myrtenol (2.6%), β-bisabolol (2.2%) and 1,8-cineole (2.1%) were found to be predominant components. The oil was also characterized by relatively high amount of oxygenated monoterpenes (69.6%). The oil was tested for fungitoxic effects against 33 agricultural pathogenic fungi using in vitro microbial growth inhibition assays. The oil exhibited considerable antifungal activity against a broad spectrum of tested fungi. Antibacterial activity of the oil was determined against 30 bacterial strains using the disc diffusion method. The oil had a very wide spectrum of antibacterial activity. However, it was not as active as penicillin. The oil showed 68.3–75.0% mortality against adults of Sitophilus granarius and Tribolium confusum, the major pests of wheat and wheat products, respectively. It can be concluded that the oil of S. hydrangea has a potential against agricultural pathogenic fungi and two stored pests, S. granarius and T. confusum.     

萼翅藤枝叶挥发油及其抗菌活性的研究

萼翅藤枝叶挥发油由GC/MS检测.树叶挥发油的52种成分中,氧化石竹烯(13.79%)、棕榈酸(11.91%)和β-石竹烯(10.45%)是主要成分.同时,树枝挥发油中的10种成分占总量的99.99%,其中主要的化学成分为棕榈酸(59.18%),亚油酸(12.70%)和邻苯二甲酸丁辛酯(8.21%).用滤纸扩散法,分别测定了枝、叶挥发油对8种微生物的抑制效果.枝、叶挥发油均具有很强的抗菌效果,并且抗细菌活性优于抗真菌活性.叶挥发油比枝挥发油具有更广谱的抑菌效果,且对所试的大多数菌株都具有更高的活性.     

Antioxidant,antimicrobial activities and comparative analysis of the composition of essential oils of leaf,stem, flower and aerial part of Nepeta hindostana

Nepeta hindostana (B.Heyne ex Roth) Haines is belonging to lamiaceae family and used as a component of herbal ayurvedic formulation Abana which is useful for the treatment of Hyperlipidemia, Dyslipidemia and Hypercholesterolemia. In the present study, the essential oil from aerial parts (flower, leaves, stem and whole aerial) was collected and the major constituents of essential oils were characterized by GC-FID and GC/MS and further evaluated for their antioxidant and antimicrobial efficacy. The major components of the essential oil were sesquiterpene hydrocarbons (77.2, 80.5, 62.5, 77.8%), oxygenated sesquiterpenes (10.5, 9.2, 20.6, 9.2%) and oxygenated monoterpenes (5.3, 4.2, 2.5, 3.6%) in leaves, stem, flowers and aerial part, respectively. The major compounds in essential oils were identified as β-sesquiphellandrene, cadina-1,4-diene, α-cadinene, (E)-caryophyllene, α-humulene and β-bisabolene. At 100 μg/mL concentration, leaves essential oil showed strong 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging activity with the IC₅₀ 2.8 μg/mL and 34.0% by β-carotene bleaching assay. Furthermore, the antibacterial activity was tested against four Gram-negative and five Gram-positive pathogenic strains. The essential oil from flower showed potent activity (37.5 μg/ml) against S. aureus, S. mutans but was less active against Gram-negative bacterial strains. In anti-MRSA activity, leaves and flowers exhibited strong activity against S. aureus (SA-2071) and S. aureus (SA-4627) with lowest IC₅₀ value of 50–100 μg/mL. Overall, N. hinodostana (L.) essential oil represented a potential reservoir of molecules having potent antioxidant and antimicrobial potential.     

Antibacterial activity and composition of the essential oil of Ziziphora clinopodioides subsp. bungeana (Juz.) Rech. f. from Iran

The chemical composition of the essential oil obtained from the aerial flowering parts of Ziziphora clinopodioides subsp. bungeana (Juz.) Rech. f. was analyzed by GC and GC-MS. Thirty-two components representing 97.1% of the total oil were identified. Oxygenated monoterpenes (94.3%) were the predominant fraction of the oil with pulegone (65.2%), isomenthone (11.9%), 1,8-cineole (7.8%) and piperitenone (6.5%) as the main constituents. Antibacterial activity of the oil and also its two main components (pulegone and 1,8-cineole) were tested against seven bacteria. It was found that the oil exhibited interesting antibacterial activity against Staphylococcus epidermidis, S. aureus, Escherichia coli and Bacillus subtilis with MIC values of 3.75 mg/ml.     

The effect of fractionated Tagetes oil volatiles on aphid reproduction

The biological activity of essential oil volatiles from Tagetes minuta L. (Mexican marigold) against three aphid species was investigated in a series of laboratory experiments. The aphid species (Homoptera: Aphididae) studied were: Acyrthosiphon pisum (Harris) (pea aphid), Myzus persicae (Sulzer) (peach‐potato aphid), and Aulacorthum solani (Kaltenbach) (glasshouse and potato aphid). Tagetes minuta oil volatiles significantly reduced aphid reproduction (up to 100% after 5 days of exposure). The effect depended on the quantity of essential oil used, and varied with the aphid species tested. Pea aphids were the most susceptible. Tagetes minuta oil was fractionated by vacuum distillation. Fractions and three pure compounds (limonene, (Z)‐ocimene, and β‐caryophyllene) were tested using the same experimental technique. The chemical composition of the volatiles was investigated by headspace–solid phase microextraction–gas chromatography mass spectrometry (HS‐SPME‐GCMS), and the main constituents of the oil were identified. Overall, applied in equal quantity, fractions predominantly containing sesquiterpenes and oxygenated monoterpenoids were more effective in restricting aphid population growth than fractions predominantly containing monoterpenes. When tested as a pure compound, the sesquiterpene β‐caryophyllene produced a greater effect than the monoterpenes limonene and ocimene. The study demonstrates that T. minuta oil volatiles have potential for aphid control.     

Chemical Composition and Antimicrobial Activity of the Essential Oils from New Caledonian Citrus macroptera and Citrus hystrix

The essential oils from the leaves of Citrus macroptera and C. hystrix, collected in New Caledonia, have been analyzed by gas chromatography/mass spectrometry (GC/MS) and evaluated for their antimicrobial activity. A total of 35 and 38 constituents were identified, representing 99.1 and 89.0% of the essential oils, respectively. Both essential oils were rich in monoterpenes (96.1 and 87.0%, resp.), with β‐pinene as major component (33.3 and 10.9%, resp.), and poor in limonene (2.4 and 4.7%, resp.). Other main components of C. macroptera oil were α‐pinene (25.3%), p‐cimene (17.6%), (E)‐β‐ocimene (6.7%), and sabinene (4.8%). The essential oil of C. hystrix was characterized by high contents of terpinen‐4‐ol (13.0%), α‐terpineol (7.6%), 1,8‐cineole (6.4%), and citronellol (6.0%). The antimicrobial activity was evaluated against five bacteria and five fungi strains. Both oils were inactive against bacteria. However, the C. macroptera leaf oil exhibited a pronounced activity against Trichophyton mentagrophytes var. interdigitale, with a minimal‐inhibitory concentration (MIC) of 12.5 μg/ml.     

Norsesquiterpene hydrocarbon, chemical composition and antimicrobial activity of Rhaponticum carthamoides root essential oil

A detailed analysis of Rhaponticum carthamoides (Willd.) Iljin root essential oil was carried out by GC, GC-MS and GC-FTIR techniques. In total, 30 components were identified, accounting for 98.0% of total volatiles. A norsesquiterpene 13-norcypera-1(5),11(12)-diene (22.6%), followed by aplotaxene (21.2%) and cyperene (17.9%), were isolated and their structures confirmed by 1D and 2D-NMR spectra (COSY, ROESY, HSQC, HMBC and INADEQUATE). Selinene type sesquiterpenes and aliphatic hydrocarbons were among minor constituents of the essential oil. The oil exhibited antimicrobial activity against 5 of 9 strains of bacteria and yeast, when tested using broth micro-dilution method. Minimum inhibitory concentrations ranged between 32 and 256 μg/ml.     

Antimicrobial activity and phytochemical analyses of Polygonum aviculare L. (Polygonaceae), naturally growing in Egypt

Polygonum aviculare (Polygonaceae) is an herb commonly distributed in Mediterranean coastal regions in Egypt and used in folkloric medicine. Organic and aqueous solvent extracts and fractions of P. aviculare were investigated for antimicrobial activities on several microorganisms including bacteria and fungi. Phytochemical constituents of air-dried powered plant parts were extracted using aqueous and organic solvents (acetone, ethanol, chloroform and water). Antimicrobial activity of the concentrated extracts was evaluated by determination of the diameter of inhibition zone against both Gram-negative and Gram-positive bacteria and fungi using paper disc diffusion method.Results of the phytochemical studies revealed the presence of tannins, saponins, flavonoids, alkaloids and sesquiterpenes and the extracts were active against both Gram-negative and Gram-positive bacteria. Chloroform extract gave very good and excellent antimicrobial activity against all tested bacteria and good activity against all tested fungi except Candida albicans. Structural spectroscopic analysis that was carried out on the active substances in the chloroform extract led to the identification of panicudine (6-hydroxy-11-deoxy-13 dehydrohetisane).Evaluation of the antimicrobial activity of panicudine indicated significant activity against all tested Gram-negative and Gram-positive organisms. Panicudine displayed considerable activity against the tested fungi with the exception of C. albicans. Antimicrobial activity of the extracts was unaffected after exposure to different heat treatments, but was reduced at alkaline pH. Studies of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of panicudine on the tested organisms showed that the lowest MIC and the MBC were demonstrated against Salmonella paratyphi, Bacillus subtilis and Salmonella typhi and the highest MIC and MBC were against Staphylococcus aureus.     

Phytotoxicity and antifungal properties of the essential oil from the Juniperus polycarpos var. turcomanica (B. Fedsch.) R.P. Adams leaves

This study was performed to investigate the constituents, in vitro antifungal activity and phytotoxicity potential of the essential oil from Juniperus polycarpos var. turcomanica leaves. The essential oil was analyzed by GC–FID, and GC/MS, which predominantly contains α-pinene (51.21%), germacrene–B (4.80%), and ∆-cadinene (2.56%). The antifungal activity of the essential oil against some phytopathogenic fungi, including Alternaria alternata, Colletotrichum trichellum, Curvularia fallax, Cytospora sacchari, Fusarium oxysporum, and Macrophomina phaseolina was performed through disk diffusion and agar dilution assays. The essential oil of J. polycarpos var. turcomanica had high antifungal activity against tested phytopathogenic fungi. The most susceptible fungi to the essential oil were C. trichellum in agar dilution and M. phaseolina and C. fallax in disk diffusion methods, whereas, the most resistant fungus to the essential oil was obtained from A. alternata in both assays. Screening methods had an influence on antifungal activity of the essential oil as most of the tested fungi in this study were shown to be more resistant in disc diffusion methods. According to the phytotoxic assay results, the essential oil from J. polycarpos var. turcomanica had high phytotoxicity against three species of weeds, including P. oleracea L., A. retroflexus L., and D. stramonium L. The results of this research suggest that the herbicidal and antifungal activities of the essential oil from J. polycarpos var. turcomanica can be attributed to its major group of constituents, monoterpenes hydrocarbons.     

Composition and antimicrobial activity of essential oils from Centaurea sessilis and Centaurea armena

The essential oils of air-dried Centaurea sessilis and Centaurea armena obtained by hydrodistillation were analyzed by gas chromatography-mass spectrometry (GC-MS). Forty and twenty components were identified in the essential oils and the main component of these taxons was beta-eudesmol in the ratios of 12.4% and 19.3% from C. sessilis and C. armena, respectively. The antimicrobial activity of the isolated essential oil of the plants was also investigated. They showed moderate antibacterial activity against Gram-positive and Gram-negative bacteria, but no antifungal activity was observed against two yeastlike fungi.