Evaluation of characteristic aroma compounds of Citrus natsudaidai Hayata (Natsudaidai) cold-pressed peel oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by gamma-terpinene (5.30%), myrcene (2.25%) and alpha-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, alpha-pinene, beta-pinene, limonene, nonanal, gamma-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3(6)), whereas beta-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Chemistry and immunomodulatory activity of frankincense oil

The yield of steam distillation of frankincense essential oil (3%); and its physicochemical constants were determined. Capillary GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was found to contain monoterpenes (13.1%), sesquiterpenes (1%), and diterpenes (42.5%). The major components of the oil were duva-3,9,13-trien-1,5alpha-diol-1-acetate (21.4%), octyl acetate (13.4%), o-methyl anisole (7.6%), naphthalene decahydro-1,1,4a-trimethyl-6-methylene-5-(3-methyl-2-pentenyl) (5.7%), thunbergol (4.1%), phenanthrene-7-ethenyl-1,2,3,4,4a,5,6,7,8,9,10,10a-dodecahydro-1,1,4a,7-tetramethyl (4.1%), alpha-pinene (3.1%), sclarene (2.9%), 9-cis-retinal (2.8%), octyl formate (1.4%), verticiol (1.2%) decyl acetate (1.2%), n-octanol (1.1%). The chemical profile of the oil is considered as a chemotaxonomical marker that confirmed the botanical and geographical source of the resin. Biologically, the oil exhibited a strong immunostimulant activity (90% lymphocyte transformation) when assessed by a lymphocyte proliferation assay.     

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.     

Evaluation of Characteristic Aroma Compounds of Citrus natsudaidai Hayata (Natsudaidai) Cold-Pressed Peel Oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by γ-terpinene (5.30%), myrcene (2.25%) and α-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, α-pinene, β-pinene, limonene, nonanal, γ-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3⁶), whereas β-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Chemical Diversity and Antimicrobial Activity of Volatile Compounds from Zanthoxylum zanthoxyloides Lam. according to Compound Classes,Plant Organs and Senegalese Sample Locations

The chemical diversity of Zanthoxylum zanthoxyloides growing wild in Senegal was studied according to volatile compound classes, plant organs and sample locations. The composition of fruit essential oil was investigated using an original targeted approach based on the combination of gas chromatography (GC) and liquid chromatography (LC) both coupled with mass spectrometry (MS). The volatile composition of Z. zanthoxyloides fruits exhibited relative high amounts of hydrocarbon monoterpenes (24.3 – 55.8%) and non‐terpenic oxygenated compounds (34.5 – 63.1%). The main components were (E)‐β‐ocimene (12.1 – 39%), octyl acetate (11.6 – 21.8%) and decanol (9.7 – 15.4%). The GC and GC/MS profiling of fruit essential oils showed a chemical variability according to geographical locations of plant material. The LC/MS/MS analysis of fruit oils allowed the detection of seven coumarins in trace content. The chemical composition of fruit essential oils was compared with volatile fractions of leaves and barks (root and trunk) from the same plant station. Hexadecanoic acid, germacrene D and decanal were identified as the major constituents of leaves whereas the barks (root and trunk) were dominated by pellitorine (85.8% and 57%, respectively), an atypic linear compound with amide group. The fruit essential oil exhibited interesting antimicrobial activities against Staphylococcus aureus and Candida albicans, particularly the alcohol fraction of the oil.     

Essential‐Oil Composition of the Fruits of Six Heracleum L. Species from Iran: Chemotaxonomic Significance

The fruit essential oils of Heracleum persicum, H. rechingeri, H. gorganicum, H. rawianum, H. pastinacifolium, and H. anisactis from Iran were obtained by hydrodistillation and characterized by GC‐FID and GC/MS analyses. The oils of the six species were compared to determine the similarities and differences among their compositions. Overall, 36 compounds were identified in the fruit oils, accounting for 92.40–96.74% of the total oil compositions. Aliphatic esters constituted the main fraction of the oils (86.61–94.31%), with octyl acetate and hexyl butyrate as the major components. The oil compositions of species belonging to section Pubescentia (H. persicum, H. gorganicum, and H. rechingeri) were discriminated by equally high contents of both octyl acetate (13.84–20.48%) and hexyl butyrate (17.73–38.36%). On the other hand, the oils of H. rawianum, H. pastinacifolium and H. anisactis, belonging to section Wendia, showed lower hexyl butyrate contents (3.62–6.6%) and higher octyl acetate contents (48.71–75.36%) than the former. Moreover, isoelemicin was identified at low amounts (0.10–2.51%) only in the oils of the latter species. The differences in the oil composition among the six species were investigated by hierarchical cluster and principal component analyses, which indicated that the oil composition confirmed well the taxonomical classification based on the morphological and botanical data, and, thus, may provide a reliable marker to discriminate Heracleum species at the intersectional level.     

Chemical composition and antibacterial activity of the essential oil of Drimys granadensis L.f. leaves from Colombia

Drimys granadensis L.f., a native plant from Colombia, has been included in the Vademecum de Plantas Medicinales de Colombia by the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, due to its widespread use in the folk medicine for the treatment of gastrointestinal ailments. The chemical composition of the essential oil of Drimys granadensis obtained by hydrodistillation of the leaves was analyzed by GC and GC/MS analyses. A total of 85 components were identified, with the major compounds germacrene D (1, 14.7%), sclarene (9.5%), a-cadinol (7.3%), longiborneol acetate (2, 6.3%), drimenol (4.2%), (Z)-β-ocimene (3, 4.2%), a-pinene (4, 3.2%), and β-elemene (5, 2.7%). The essential oil was also tested against eight bacteria using the Kirby-Bauer disk-diffusion method. Most of the Gram-positive bacteria tested were susceptible to the D. granadensis essential oil, while the Gram-negative bacteria tested were not.     

Essential oil of trees of the genus Ocotea (Lauraceae) in Costa Rica. I. Ocotea brenesii

The chemical composition of the essential oils from leaves and wood of Ocotea brenesii Standl. growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. From the leaves, 64 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. The major constituents identified in the leaf oil were alpha-copaene (21. 1%), 8-cadinene (9.2%), spathulenol (7.3%), globulol (5.6%) and beta-caryophyllene (5.2%). The major constituents of the wood oil were alpha-copaene (6.6%), caryophyllene oxide (6.3%). beta-caryophyllene (6.1%) and humulene epoxide (4.6%).     

Chemical composition, antioxidant activity and inhibitory effects of essential oil of Eucalyptus teretecornis grown in north-western Himalaya against Alternaria alternata

The essential oil obtained from fresh leaves of Eucalyptus teretecornis (family Myrtaceae) was analysed by gas chromatography/mass spectrometry (GC/MS). Twenty eight compounds were identified and ??-pinene (22.55%), ??-pinene (22.50%), 1,8-cineole (19.84%), limonene (5.62%), ??-fenchol (3.10%), ??-phellandrene (2.90%), ??-eudesmol (2.66%) and 4-(2-methylcyclohex-1-enyl)-but-2-enal (2.34%) were the main components. The antifungal activity of the essential oil was assayed against Alternaria alternata using bioautography. Two main bioactive components namely a₁ (R _f ?=?0.27) and a₂ (R _f ?=?0.33) were observed that produced inhibition zone of 4?mm and 8?mm in diameter respectively. The minimum inhibitory amount (MIA) of a₁ and a₂ against A. alternata was determined as 28???g and 10???g, respectively using bioautography assay. Components corresponding to a₁ and a₂ were determined as ??-fenchol (oxygenated monoterpene) and ??-eudesmol (oxygenated sesquiterpene) respectively using GC/MS analysis. The antioxidant activity of the essential oil and its bioactive fraction was evaluated by DPPH radical scavenging assay, ??-carotene/linoleic acid bleaching assay, reducing power assay and metal chelating assay. In addition fraction of the essential oil that showed antioxidant activity was analyzed using GC/MS and ??-fenchol, 4-terpineol and carvacrol were the main components.     

Investigation of monoterpenoids rich essential oils of two Ocimum basilicum L. varieties at different agro-climatic conditions in India

India is an emerging basil essential oil producer in South-east Asia. Two high essential oil yielding hybrids, namely one inter specific hybrid between of O. basilicum and O. kilimandscharicum Gürke (HYBL-1) and another intraspecific hybrid of O. basilicum × O. basilicum (OBL-1) of basil were analyzed using GC, enantiomeric GC, NMR, enantio-GC–MS and GC–MS methods. Inter specific hybrid HYBL-1 contained high essential oil-rich in linalool (68.5%), camphor (8%), and 1,8-cineole (4.6%) as characteristic constituents among monoterpenoids, whereas β-caryophyllene (1.9%), germacrene D (1.0%), and epi-α-cadinol (1.9%) were the sesquiterpenoids at the Lucknow (North Indian conditions) and linalool (71.8%), camphor (9.4%) and 1,8-cineole (4.3%) at Hyderabad (South Indian conditions) locations. Intraspecific hybrid (OBL-1) possessed linalool (66.1%), 1,8-cineole (5.4%) and geraniol (8.6%) with sesquiterpenoids in low proportions. Inter specific hybrid HYBL-1 showed superiority over OBL-1 in the multi-location trials conducted at Lucknow and Hyderabad. Average mean performance of inter specific hybrid over locations was: herb yield 44.80 t/ha, oil content 0.63%, oil yield 188.50 kg/ha, linalool content 67.65%, camphor content 8.90% v/s OBL-1 herb yield 21.32 t/ha, oil content 0.53%, oil yield 97.50 kg/ha, linalool content 65.55%, camphor content 0.00%, respectively. The essential oil of these two hybrids subjected to enantiomer differentiation revealed a high enantiomeric excess for (3R) -(?)-linalool, whereas (1R)- (+)-camphor was recorded exclusively in inter specific hybrid. The extensive NMR experiments were performed to confirm constituents in these hybrids and found that NMR spectroscopy could also be an ideal tool for the differentiation of essential oils from commercial samples declared as natural.     

Chemical Composition Variability of Essential Oils of Daucus gracilis Steinh. from Algeria

The chemical compositions of 20 Algerian Daucus gracilis essential oils were investigated using GC‐FID, GC/MS, and NMR analyses. Altogether, 47 compounds were identified, accounting for 90 – 99% of the total oil compositions. The main components were linalool ( 18 ; 12.5 – 22.6%), 2‐methylbutyl 2‐methylbutyrate ( 20 ; 9.2 – 20.2%), 2‐methylbutyl isobutyrate ( 10 ; 4.2 – 12.2%), ammimajane ( 47 ; 2.6 – 37.1%), (E)‐β‐ocimene ( 15 ; 0.2 – 12.8%) and 3‐methylbutyl isovalerate ( 19 ; 3.3 – 9.6%). The chemical composition of the essential oils obtained from separate organs was also studied. GC and GC/MS analysis of D. gracilis leaves and flowers allowed identifying 47 compounds, amounting to 92.3% and 94.1% of total oil composition, respectively. GC and GC/MS analysis of D. gracilis leaf and flower oils allowed identifying linalool (22.7%), 2‐methylbutyl 2‐methylbutyrate (18.9%), 2‐methylbutyl isovalerate (13.6%), ammimajane (10.4%), 3‐methylbutyl isovalerate (10.3%), (E)‐β‐ocimene (8.4%) and isopentyl 2‐methylbutyrate (8.1%) as main components. The chemical variability of the Algerian oil samples was studied using statistical analysis, which allowed the discrimination of three main Groups. A direct correlation between the altitudes, nature of soils and the chemical compositions of the D. gracilis essential oils was evidenced.     

Analysis of essential oil of Coridothymus capitatus (L.) and its antibacterial and antifungal activity

The water-distilled essential oil the leaves of Coridothymus capitatus were analyzed by GC/MS and also analyzed by direct thermal desorption GC/MS. Comparison was made between two analyses techniques. The essential oil consisted mainly of monoterpenes 98.9%, while oxygenated hydrocarbons were identified as 55.6 % and non-oxygenated hydrocarbons as 43.6%. As major components were found carvacrol (35.6%), p-cymene (21.0%), thymol (18.6%), gamma-terpinene (12.3%), alpha-terpinene (3.2%), beta-myrcene (3.0%) and alpha-thujene (1.3%) by hydrodistillation and by the GC/MS method. The direct thermal desorption GC/MS analysis also showed the same major components, namely carvacrol (51.6%), thymol (21.7%), p-cymene (9.7%) gamma-terpinene (8.2%), alpha-terpinene (1.64%). The essential oil of C. capitatus showed strong activity against S. aureus, P. vulgaris, P. aeruginosa, E. coli, K. pneumonia, B.     

Aromatic components of the leaves of the New Zealand lemonwood tree Pittosporum eugenioides

The major aromatic components of the essential leaf oil of the New Zealand lemonwood tree Pittosporum eugenioides are octyl acetate (33%), terpinen-4-ol (13%), decanol (6%) and (Z)-hex-3-enol (5%). These products are responsible for the characteristic Citrus-like aroma which is detected when the leaves are crushed, a phenomenon which provided the species with its common name. The major component of the oil, octyl acetate is also an abundant component of the essential oils of Heracleum and Boswellia species.     

Essential oil composition of Angelica archangelica L. (Apiaceae) roots and its antifungal activity against plant pathogenic fungi

This study reports the results of gas chromatography–mass spectrometry (GC–MS) analyses of the essential oil of Angelica archangelica L. (Apiaceae) roots, as well as its in vitro antifungal activity against 10 plant pathogenic fungi. Moreover, the essential oil was evaluated for its antifungal activity using the agar dilution method, and also minimum inhibitory concentrations and minimum fungicidal concentrations were determined. The major compounds identified by GC–MS were α-pinene (21.3%), δ-3-carene (16.5%), limonene (16.4%), and α-phellandrene (8.7%). The oil showed in vitro antifungal activity against some species of the Fusarium genus, Botrytis cinerea, and Alternaria solani. Our study indicates that the oil of A. archangelica could be used as a control agent for plant pathogenic fungi in natural formulations.     

Chemical composition and antimicrobial activity of the essential oil of Scutellaria barbata

The essential oil of Scutellaria barbata was obtained by hydrodistillation with a 0.3% (v/w) yield and analysed by GC and GC-MS. The main compounds in the oil were hexahydrofarnesylacetone (11.0%), 3,7,11,15-tetramethyl-2-hexadecen-1-ol (7.8%), menthol (7.7%) and 1-octen-3-ol (7.1%). The antimicrobial activity of the oil was evaluated against 17 microorganisms using disc diffusion and broth microdilution methods. The gram-positive bacteria, including methicillin-resistant Staphlococcus aureus, were more sensitive to the oil than gram-negative bacteria and yeasts.     

Chemical Variability and Antioxidant Activity of Limbarda crithmoides L. Essential Oil from Corsica

The chemical compositions of 25 Corsican Limbarda crithmoides ssp. longifolia essential oils were investigated for the first time using GC‐FID, GC/MS, and NMR analyses. Altogether, 65 compounds were identified, accounting for 90.0–99.3% of the total oil compositions. The main components were p‐cymene ( 1 ; 15.1–34.6%), 3‐methoxy‐p‐cymenene ( 4 ; 11.8–28.5%), 2,5‐dimethoxy‐p‐cymenene ( 5 ; 5.9–16.4%), thymol methyl ether ( 6 ; 1.3–14.9%), α‐phellandrene ( 2 ; 0.9–11.9%), and α‐pinene ( 3 ; 0.2–13.4%). The chemical variability of the Corsican oil samples was studied using multivariate statistical analysis, which allowed the discrimination of two main clusters. A direct correlation between the water salinities of the plant locations and the chemical compositions of the L. crithmoides essential oils was evidenced. Indeed, essential oils rich in 1 (30.4–34.6%) were found in samples growing in the wetlands of the southern oriental coast, which exhibit high salinity levels (24.4±0.2–33.9±0.2 ppt), and essential oils with lower contents of 1 (15.1–27.3%) were isolated form samples growing in the wetlands of northern Corsica, which exhibit lower salinity levels (10.90±0.20–15.47±0.15 ppt). The antioxidant potential of L. crithmoides essential oil was also investigated, by assessing the DPPH^.‐ and ABTS^.+‐scavenging activities and the reducing power of ferric ions, and was found to be interesting. Moreover, using bioassay‐guided fractionation of the essential oil, a higher antioxidant activity was obtained for the oxygenated fraction and both ester and alcohol subfractions.     

Analysis of the essential oil from the roots of Eupatorium cannabinum subsp. corsicum (L.) by GC, GC-MS and 13C-NMR

Eupatorium cannabinum subsp. corsicum (L.) is an endemic subspecies from the island of Corsica. The essential oil from the roots of this aromatic plant has been studied by GC, GC-MS and by 13C-NMR. In contrast to the essential oil from the aerial parts, which is dominated by hydrocarbon compounds (76.9%) and particularly by sesquiterpene components (43.3%), the essential oil from the roots was characterized by a high content of oxygenated compounds (61.0%), particularly oxygenated monoterpenes (54.0%). In the root oil, 106 components were identified representing 96.1% of the total amount. This oil was dominated by the monoterpenes esters (33%), the major components of which were neryl isobutyrate (17.6%), thymyl methyl oxide (15.1%), delta-2-carene (14.5%) and beta-pinene (5.7%). Aromatic esters, nerol derivatives (esters and diesters) and a benzofuran were investigated by GC-MS using different ionization modes including electron impact ionization, and positive- and negative-chemical ionization. These components have not previously been reported in the essential oil of aerial parts of E. cannabinum from Corsica island.     

Volatile secondary metabolites of Micromeria dalmatica Benth. (Lamiaceae): biosynthetical and chemotaxonomical aspects

Analysis by GC and GC/MS of the essential oil obtained from above-ground parts of Micromeria dalmatica Benth. allowed the identification of 116 components, comprising 93.6% of the total oil composition. The major compounds are 3-oxygenated p-menthane monoterpenes and were identified as pulegone (29.6%), menthone (11.7%), and piperitenone (10.8%). The chemical composition of this and additional 30 oils obtained from selected Micromeria Benth. taxa were compared by using multivariate statistical analysis (agglomerative hierarchical cluster analysis and principal component analysis (PCA)). The results of statistical analyses, as well as the domination of different concurrent p-menthane-skeleton-type monoterpene biosynthetical sub-branches in the compared M. dalmatica samples, implied the occurrence of at least two different chemotypes of the mentioned species.     

Antimicrobial activity, essential oil composition and micromorphology of trichomes of Satureja laxiflora C. Koch from Iran

The antimicrobial activity, essential oil composition and micromorphology of trichomes of Satureja laxiflora C. Koch, a native plant from Iran, were studied. The essential oil was obtained from the aerial parts at the flowering stage by hydrodistillation, and analyzed by GC and GC/MS. Thirty-three compounds representing 99.1% of the total oil were characterized. The major compounds were thymol (63.9%) and gamma-terpinene (11.9%) followed by carvacrol (4.8%), p-cymene (3.9%), geraniol (3.2%) and geranyl acetate (3.1%). Furthermore, the essential oil and its three main components were tested against two bacteria and three fungi. The result of the bioassays has been shown that the oil possesses potent antimicrobial property. Chemical studies confirmed that a major portion of this antimicrobial activity is due to thymol present in the oil. Micromorphological analysis by SEM of both vegetative and reproductive organs revealed the presence of abundant sessile capitate and sparse short-stalked glandular trichomes along with retrorse eglandular hairs, giving useful diagnostic characters for identification of this medicinal plant.     

Cytotoxic Activity of Cunila angustifolia Essential Oil

The Cunila angustifolia essential oil was obtained from fresh leaves by hydrodistillation and analyzed by GC‐FID and GC‐MS to determine its chemical composition. The essential oil presented pulegone (29.5 %) and isomenthol (27.0 %) as major components, and other compounds such as menthone (8.6 %), neomenthol (7.2 %), menthyl acetate (2.5 %) and caryophyllene oxide (2.0 %) were identified. The cytotoxic activity of the essential oil was evaluated by MTS assay, with the human cancer cell lines of the lung (A549), breast (MCF‐7) and skin melanoma (SK‐Mel‐28). The assay showed the highest selectivity, to MCF‐7 cell lines, with IC₅₀ equal to 34.0 μg mL^?1, low selectivity for SK‐Mel‐28 cell lines, with IC₅₀ equal to 279.9 μg mL^?1, and no mortality to A549 cell lines.