Content Of Monoterpene Hydrocarbons Research Articles

Volatile Profiles and DNA Barcodes of Myrtaceae Species with Occurrence in the Brazilian Amazon.

Myrtaceae family includes many species with taxonomic challenges, making it one of the most complex families to identify. This study used DNA barcoding to find molecular markers for species authentication based on the Myrtaceae family's chemical composition and genetic diversity. Essential oils and genetic material were extracted from the leaves of six different species: Eugenia uniflora, E. patrisii, Myrcia splendens, Psidium guajava, P. guineense, and Psidium sp. The samples were analyzed based on compound classes and grouped into two categories. Group I included samples with high amounts of oxygenated sesquiterpenes (3.69-76.05 %) and fatty acid derivatives (0.04-43.59 %), such as E. uniflora, Myrcia splendens, and E. patrisii. Group II included samples P. guajava, P. guineense, and Psidium sp., which had a significant content of monoterpene hydrocarbons (0.69-72.35 %), oxygenated sesquiterpenes (8.06-68.1 %), phenylpropanoids (0.45-22.59 %), and sesquiterpene hydrocarbons (0.27-21.84 %). The PsbA-trnH gene sequences had a high genetic variability, allowing the species to be distinguished. A phylogenetic analysis showed two main clusters with high Bootstrap values corresponding to the subtribes Eugeniineae, Myrciinae, and Pimentinae. The results suggest a weak correlation between genetic and chemical data in these Myrtaceae species.

Qualitative traits and peel essential oil profiles of 24 Italian and international lemon varieties

Lemon (Citrus limon L. Burm. f.) is used for fresh consumption because it is rich in several nutraceutical products especially vitamin C. The physicochemical properties and the bioactive compounds of the peel, such as the essential oil, are strictly depended on the genotype. In this context, peel and juice qualitative traits of 24 lemon cultivars were described: 20 varieties of the Italian germplasm, mostly belonging to Femminello (F.) lines, and 4 international varieties were studied. This study which may be considered one of the few examples carried out on a large number of varieties of a single Citrus species, was conducted over two years and the oils collected by hydro-distillation of the flavedo were analyzed by GC-FID and GC-MS. Differences were observed in the oil yields. For an easier comparison the essential oils’ component were subdivided in five classes: monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes and others (not terpenoidic compounds). Among the monoterpene hydrocarbons, in all the cultivars the most abundant compounds were limonene, followed by β-pinene and γ-terpinene. In particular, Monachello showed the highest content of monoterpene hydrocarbons, while the lowest value was observed in F. Carrubaro, Fino and Akragas. Femminello lines are interesting cultivars for qualitative traits of the juice (organic acids and vitamin C) and for the highest content of volatile compounds in the peel, such as limonene, myrcene, β-pinene, α-pinene, γ-terpinene and sabinene. Significant differences in morphological and physicochemical traits were observed: fruits of Lemox, F. Adamo and F. Scandurra showed to be seedless, while high acidity content was observed in F. 2Kr, which also showed the highest vitamin C content.

Chemical composition and antioxidant activity of black pepper (Piper nigrum L.) fructus essential oil hydrodistillation fractions

The aim of this study was to examine the effect of hydrodistillation time on the chemical composition and antioxidant activity of collected essential oils’ (EOs’) fractions from black pepper fructus for five hydrodistillation periods: I (0-15 min), II (15-30 min), III (30-60 min), IV(60-90 min) and V (90-120 min). In this way, an essential oil with the desired chemical composition and antioxidant activity can be selected. The essential oil was obtained by Clevenger-type hydrodistillation (CHD). The qualitative and quantitative composition of the collected EOs’ fractions was determined by GC-MS and GC-FID analysis. The efficiency of EOs’ fractions to scavenge DPPH radicals was evaluated spectrophotometrically. Essential oil yield was 3.0 ± 0.050 ml/100 g of plant material after 120 min of CHD. The content of monoterpene hydrocarbons and aromatic compounds decreased, while the content of oxygenated monoterpenes, sesquiterpene hydrocarbons and oxygenated sesquiterpenes increased with the time of CHD. The most abundant compound of EOs’ fractions was (E)-caryophyllene, whose content increased with the time of CHD (I-V: 24.9-36.6%). Results indicated that all collected EOs’ fractions exhibited antioxidant activity (EC50 values were in the range I-V: 81.27±0.327–8.02±0.044 mg/ml), where fraction V showed the highest activity. This study proved that CHD time and fractionation affect the composition and antioxidant activity of black pepper essential oil. Future research may be extended to examine other biological activities of black pepper EOs’ fractions, as well as synergistic effects of other identified active components of the essential oil, in addition to (E)-caryophyllene, that would affect biological activities.

Ploidy affects phytochemistry and micromorphology of Thymus persicus (Ronniger ex Rech.f.) Jalas: An in vitro investigation

Thymus persicus (Ronniger ex Rech. f.) Jalas (Lamiaceae) is an endemic and valuable essential oil-bearing plant. Herein, the effect of ploidy level on both anatomical structure and essential oil composition was investigated. Leaves of in vitro-induced tetraploids had more glandular peltate, capitate, and elongated non-glandular trichomes compared to diploids. Gas chromatography-flame ionization detector (GC-FID), and GC–mass Spectrometry (GC-MS) techniques were employed to unravel chemicals in hydro-distilled essential oils from in vitro diploid, tetraploid, and mixoploid clones. Notably, 21, 27 and 17 compounds representing 97.0%, 96.9%, and 96.7% of the total essential oils were identified and quantified in diploids, tetraploids, and mixoploids plants, respectively. A wide chemical variability was observed so much so that thymol (32.8%), α-terpineol (26.4%), and carvacrol (6.2%) were the main constituent in diploids, while carvacrol (33.85%), δ-selinene (8.79%), ishwarone (8.23%), and octanoic acid (8.07%) were in tetraploids and mixoploids mostly accounted in δ-Selinene (21.26%), pogostol (13.92%), methyl thujate (10.94%), and (2E,6E)-farnesyl acetate (10.28%). To further underline the ploidy effects, it was observed a strong decrease in the contents of monoterpene hydrocarbons and oxygenated monoterpene hydrocarbons in tetraploids and myxoploids. The sesquiterpene hydrocarbons showed an inverse behaviour.

Resilience of Stevia rebaudiana (Bertoni) Bertoni in the Underwater Biospheres of Nemo’s Garden®: Adaptation to New Cultivation Systems

The Nemo's Garden® project is an alternative production system for areas with scarce cultivable land but significant presence of water; thus, it is an interesting intervention to address the climate crisis. This work aimed to evaluate the micromorphological, biochemical, and phytochemical characteristics of Stevia rebaudiana (Bertoni) Bertoni grown underwater compared to the terrestrial specimens. The micromorphological analyses, performed on the leaves using light microscopy, fluorescence microscopy, and scanning electron microscopy, evidenced a general uniformity of the trichome morphotype and distribution pattern. The histochemical investigation indicated the simultaneous presence of terpenes and polyphenols in the trichome secreted material from the underwater samples and a prevailing polyphenolic content in the terrestrial specimens; this was also confirmed by biochemical analyses (26.6 mg GAE/g DW). The characterization of non-volatile components, performed using HPLC-MS, showed similar chemical profiles in all the samples, which were characterized by phenolic compounds and steviol glycosides. The volatile compounds, evaluated using HS-SPME coupled with GC-MS, showed sesquiterpene hydrocarbons as the main class in all the analyzed samples (80.1-93.9%). However, the control plants were characterized by a higher content of monoterpene hydrocarbons (12.1%). The underwater biosphere environment did not alter S. rebaudiana micro-morphological characters, although slight qualitative changes were evidenced for the compounds produced as a response to the growth conditions.

Chemical composition, antimicrobial and antioxidant activities of the essential oil of Italian Prangos trifida (Mill.) Herrnst. & Heyn

In this work, the essential oil of the aerial parts of a not previously investigated accession of Prangos trifida (Mill.) Herrnst. & Heyn (Apiaceae), collected in Northern Italy, was analysed by GC/MS. Twenty-five compounds were identified, accounting for 91.30% of the total oil, which is characterised by a high content of monoterpene hydrocarbons (71.26%). The main constituents of the essential oil were cis-β-ocimene (18.12%), α-phellandrene (12.14%), sylvestrene (11.32%), p-mentha-1,3,8-triene (9.56%) and α-pinene (8.85%). The essential oil of P. trifida showed a good antimicrobial activity directed above all against Gram-positive bacteria, and had an interesting antioxidant activity, thus making it an excellent candidate for future cosmetic and pharmaceutical applications.

Chemical composition, antioxidant and anticholinesterase activity of the essential oil of algerian cachrys sicula L

In this work, in order to explore a new Algerian medicinal plant used in traditional medicine, the essential oil of the leaves of Cachrys sicula L. (Apiaceae) collected from Algeria, obtained by hydrodistillation, was analyzed by GC/MS. Thirty-two compounds were identified accounting for 98.6% of the total oil, which is characterized by a high content of monoterpene hydrocarbons (74.8%). The main constituents of the essential oil were β-pinene (17.9%), sabinene (17.8%), myrcene (12%), and α-pinene (11.4%). In vitro antioxidant activity of the essential oil was assayed by three methods, namely ABTS•+, metal chelating, and DPPH• assays. The antioxidant activity of the oil was higher in the ABTS•+ method. Anticholinesterase activity was screened by the Ellman method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are the chief enzymes of Alzheimer’s disease. The results showed mild acetylcholinesterase and good butyrylcholinesterase inhibitory effects.

Characterization of Essential Oils from Different Taxa Belonging to the Genus Teucrium in Sardinia Island, Italy.

The genus Teucrium L. (Lamiaceae) is a genus growing in mild climate zones, particularly in the Mediterranean Basin and Central Asia. It is represented by 11 taxa in Sardinia (Italy), living commonly in sunny habitats. In this study, the following eight Sardinian Teucrium taxa were selected, and the essential oils (EOs), obtained by stem distillation, were analyzed by GC–FID and GC–MS: T. capitatum subsp. capitatum, T. chamaedrys subsp. chamaedrys, T. flavum subsp. glaucum, T. marum, T. massiliense, T. scordium subsp. scordioides, T. scorodonia, and T. subspinosum. The comprehensive analyses led to the identification of 87 constituents representing the majority of the volatile compounds. Significant differences, both qualitative and quantitative, were observed between the taxa. Overall, monoterpenes and sesquiterpenes characterized all Teucrium EOs: T. capitatum subsp. capitatum and T. flavum subsp. glaucum revealed the highest content of monoterpene hydrocarbons, while in the other Teucrium taxa sesquiterpene hydrocarbons prevailed. Worthy of note, diterpenes were found only in T. marum and T. subspinosum, whereas T. massiliense was rich in non-terpenic oxygenated compounds. To the best of our knowledge, this is the first comprehensive report on the chemical composition of EOs obtained from Sardinian Teucrium species.

Small Functional Foods: Comparative Phytochemical and Nutritional Analyses of Five Microgreens of the Brassicaceae Family.

Microgreens are the seedlings of herbs and vegetables which are harvested at the development stage of their two cotyledonary leaves, or sometimes at the emergence of their rudimentary first pair of true leaves. They are functional foods, the consumption of which is steadily increasing due to their high nutritional value. The species of the Brassicaceae family are good sources of bioactive compounds, with a favorable nutritional profile. The present study analyzed some phytochemical compounds with nutritional values, such as chlorophylls, polyphenols, carotenoids, anthocyanins, ascorbic acid, total and reducing sugars, and the antioxidant activity of five Brassicaceae species: broccoli (Brassica oleracea L.), daikon (Raphanus raphanistrum subsp. sativus (L.) Domin), mustard (Brassica juncea (L.) Czern.), rocket salad (Eruca vesicaria (L.) Cav.), and watercress (Nasturtium officinale R.Br.). Broccoli had the highest polyphenol, carotenoid and chlorophyll contents, as well as a good antioxidant ability. Mustard was characterized by high ascorbic acid and total sugar contents. By contrast, rocket salad exhibited the lowest antioxidant content and activity. The essential oil (EO) composition of all of these species was determined in order to identify their profile and isothiocyanates content, which are compounds with many reported health benefits. Isothiocyanates were the most abundant group in broccoli (4-pentenyl isothiocyanate), mustard (allyl isothiocyanate), and watercress (benzyl isothiocyanate) EOs, while rocket salad and daikon exhibited higher contents of monoterpene hydrocarbons (myrcene) and oxygenated diterpenes (phytol), respectively. Broccoli microgreens exhibited the overall best nutritional profile, appearing as the most promising species to be consumed as a functional food among those analyzed.

Chemical Composition, Antimicrobial Activity and Chemotaxonomy of Essential Oil of Aerial Parts of Hypericum rumeliacum Boiss. Species

The essential oil isolated from aerial parts of Hypericum rumeliacum Boiss. was analyzed by GC and GC/MS. Forty three identified compounds accounted for 98.8 % of the total oil. The main components of the oil were: (E)-β-ocimene (18.2 %), β-pinene (14.7 %), (Z)-β-ocimene (13.0 %), dodecanal (7.4 %) germacrene D (5.8 %) and myrcene (5.8 %). The volatile profile of H. rumeliacum was characterized by a large content of monoterpene hydrocarbons (68.2 %), followed by non-terpenoids (14.4 %) and sesqiuterpenoids (11.8 %). Multivariate statistical analyses (agglomerative hierarchical cluster analysis and principal component analysis) were used to compare and discuss interrelationship within the mentioned species based on essential oil profiles. The oil was tested in a broth microdilution assay against five bacterial and two fungal strains and found to have mainly moderate antimicrobial effects.

One step extraction of essential oils and pectin from pomelo (Citrus grandis) peels

Pectin and essential oils (EOs) were simultanuously extracted from pomelo peels by adding citric acid into water used for hydrodistillation of pomelo peels. The effect of citric acid concentrations (0–0.55%) on the chemical composition and yield of EOs and pectin yield were investigated. EO yields and the chemical compostion were not significantly affected by citric acid. EO yields were about 1% fresh weight or 4.6% dry weight at all tested concentrations of citric acid. Total monoterpene hydrocarbon content of essential oils in all treatments was not significantly different and within narrow range of 93–94.71%, in which limonene, a main component of pomelo EOs, fluctuated around 89%. However, pomelo pectin yield increased with citric acid concentration. It varied from 11 to 24% as citric acid concentration rose from 0 to 0.55% (equivalent to pH from 7.3 to 2.1). In short, hydrodistillation using citric acid solution is a feasible processing method that combines two different extraction processes into one.

Effect of cold plasma on essential oil content and composition of lemon verbena.

Cold plasma is known as a novel nonthermal processing method for decontamination of medicinal and aromatic plants (MAPs); however, there are little research studies about its effects on active ingredients of these plants. The aim of this research was to investigate the influence of low‐pressure cold plasma (LPCP) treatments (1, 3, and 5 min) on the essential oil (EO) content and composition of lemon verbena leaves. The EO content was determined using hydro‐distillation, and the composition of the extracted EOs was quantified using gas chromatography and gas chromatography–mass spectrometry techniques. The results showed that by increasing the LPCP treatment duration, the EO content was reduced from 1.2 to 0.9 (% v/w). The highest content of monoterpene hydrocarbons (e.g., limonene) and oxygenated sesquiterpenes (e.g., spathulenol and globulol) was also observed in LPCP‐treated ones, whereas the oxygenated monoterpenes (e.g., citral) content of control was measurably higher than those treated with LCPC.

Bioactive Constituents of Juniperus turbinata Guss. from La Maddalena Archipelago.

A comprehensive phytochemical study of Juniperus turbinata (Cupressaceae) collected from La Maddalena Archipelago (Sardinia, Italy) is reported. Both the essential oil and the ethanolic extract obtained from the aerial parts were analyzed. The essential oil appears to belong to a new chemotype compared to other Mediterranean juniper accessions, as it was favored by geographic isolation of the isles. It showed a low content of monoterpene hydrocarbons and α-terpineol, ent-manoyl oxide, 1,10-di-epi-cubenol as the major constituents. The ethanolic fraction contained mainly diterpenoids. Among these, 15-formyloxyimbricatolic acid (7) is a new natural product since it has hitherto been obtained only by synthetic route. The phenolic fraction contained biflavonoids: cupressuflavone (9), followed by minor amounts of amentoflavone (10) and hinokiflavone (11). The essential oil and six purified compounds (1 - 4, 8 and 9) were assessed for biological activities, namely antioxidant (assessed by DPPH· , ABTS·+ and FRAP methods) and cytotoxic effects towards selected human tumor cell lines (MDA-MB 231, A375 and HCT116 cells). Compound 3 exhibited higher radical scavenging activity against ABTS·+ radical than the reference Trolox. Noteworthy, compound 8 showed powerful effects towards tumor cell lines, with IC50 values in the range of 0.060 - 0.201 μm, which make it a promising anticancer drug candidate.

Volatile Secondary Metabolites in Cascarillo (Ocotea caparrapi (Sandino-Groot ex Nates) Dugand - Lauraceae)

In this work, the chemical analysis of the volatile fractions obtained by simultaneous distillation-extraction of aerial parts of a species of Ocotea aff. O. caparrapi known as “Cascarillo” was carried out by GC-MS. The main components identified were: α-pinene (23.9%) and β-pinene (14.7%), in the resin; α-terpineol (26.6%) and methyleugenol (14.7%), in the leaves; elemicin (31.3%) and methyleugenol (31.1%), in the branch bark; myristicin (35.4-46.1%), terpinen-4-ol (14.9-26.3%), and α-terpineol (17.5-21.3%), in stem bark. A high content of monoterpene hydrocarbons (82.6% and 51.8%) were found in the resin and leaves; and propenylbenzenes (66.5%), in the branch bark. Oxygenated monoterpenes (44.5-57.3%) and propenylbenzenes (52.3-38.7%) constituted the stem bark. The identification of methyleugenol, elemicin and myristicin, in the volatile fractions, allowed us to establish a relationship between the Ocotea sp. of our study with O. caparrapi and O. cymbarum.

Chemical characterisation and biological activity of leaf essential oils obtained from Pistacia terebinthus growing wild in Tunisia and Sardinia Island

In the present work the chemical compositions, measured by GC and GC-MS, of the essential oils obtained by hydrodistillation from leaves of Pistacia terebinthus collected in Bizerte (Tunisia) and Baunei (Italy) are reported. Both essential oils possessed high content of monoterpene hydrocarbons (86.3% and 90.9%, respectively), being α-pinene (62.4 vs. 35.0)%, camphene (3.0 vs. 2.4)%, β-pinene (12.1 vs. 4.5)%, terpinolene (1.7 vs. 35.2)% and β-phellandrene (3.8 vs. 4.5)% the main components. The Tunisian essential oil exhibited higher antifungal activity than the Italian one. Cryptococcus neoformans and the majority of dermatophyte strains showed more sensitivity to the Tunisian oil, when compared to Candida strains, in particular Trichophyton rubrum, Microsporum canis and Epidermophyton floccosum, with MIC and MLC values in the range (0.16–0.32) μL/mL. The results obtained support the use of the oil from Tunisia for the treatment of dermatophytosis.

Chemical composition and yield of essential oils from Bakhtiari savory (Satureja bachtiarica Bunge.) under different extraction methods

Bakhtiari savory is a perennial aromatic herb distributed in Zagros mountain range, southwestern Iran. To determine the effect of extraction methods on qualitative and quantitative characteristics of the essential oil of Bakhtiari savory was extracted by different methods. Conventional methods [hydrodistillation by two Clevenger-type apparatus: British Pharmacopeia (HDBP) and Research Institute of Forests and Rangelands, Iran (HDRIFR), and traditional steam and water distillation (TSWD)], an innovative technique steam distillation (SDinnov), microwave-assisted steam hydro-diffusion (MSHD 400 and 800W), and microwave-assisted hydro-diffusion (MHD 400 and 800W) were used to extract essential oil from the aerial parts of savory and their results were compared. The essential oils of all samples were analyzed using GC–FID, GC/MS, and for comparison, a sample was analyzed using head space solid-phase microextraction (HS-SPME). The highest essential oil yields were obtained from two methods, including HDBP, and MSHD 400W. Significant differences occurred among the major constituents in essential oils from extraction methods, including thymol, carvacrol, ρ-cymene, and γ-terpinene. The highest amounts of thymol and carvacrol were obtained from MHD (800W) method in comparison other methods. The highest content of monoterpene hydrocarbons was obtained from HS-SPME, whereas the highest percentage of oxygenated monoterpenes was achieved from MHD (800W) method. In conclusion, extraction of the essential oil from Bakhtiari savory with microwave-assisted hydro-diffusion (MHD) was better in terms of energy saving, extraction time, oxygenated fraction (thymol and carvacrol), and product quality.

Volatile constituents of Haplophyllum buhsei Boiss. flowering aerial parts

The essential oil composition of flowering aerial parts of Haplophyllum buhsei Boiss. (Rutaceae) from Iran was analyzed for the first time using gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). Thirty six compounds comprising 92.2% of the total oil were characterized. The main components were b-caryophyllene (12.9%), limonene (9.7%), b-pinene (7.9%), linalool (7.4%), α -pinene (6.4%) and 1,8-cineole (5.5%). Volatile oil of Haplophyllum buhsei Boiss. flowering aerial parts was dominated by the high content of monoterpene hydrocarbons (39.2%) and oxygenated monoterpenes (23.2%). KEY WORDS : Haplophyllum buhsei Boiss., Rutaceae, Essential oil, b-Caryophyllene, Limonene Bull. Chem. Soc. Ethiop. 2015 , 29(2), 327-330 DOI: http://dx.doi.org/10.4314/bcse.v29i2.15

Chemical composition, antibacterial and repellent activities of Azorella trifurcata, Senecio pogonias, and Senecio oreophyton essential oils

The antibacterial and insect-repellent activities of the essential oils (EOs) from Argentinian medicinal plants Azorella trifurcata (Gaertn.) Pers., Senecio cfr. oreophyton J. Remy and Senecio cfr. pogonias Cabrera, were investigated. All EOs showed good repellent properties against Triatoma infestans Klug, the vector of the Chagas disease, with percent repellence values between 60% and 70% at 24h compared with positive control N-N diethyl-m-methylbenzamide (DEET) and moderate activity against the bacteria tested with minimum inhibitory concentration (MIC) values between 31.2 and 2000μg/ml. The A. trifurcata, Senecio pogonias and Senecio oreophyton EOs, obtained by hydrodistillation, were characterized by GC-FID and GC/MS analyses. Spathulenol (38.2%), myrtenyl acetate (8.4%), α-terpineol (4.5%), limonene (9.8%) and α-thujene (5.4%) were the main constituents in the EO of A. trifurcata. The S. pogonias and S. oreophyton EOs are characterized by a high content of monoterpene hydrocarbons (92% and 95.1%, respectively) with α-pinene, the main component in both oils. To our knowledge, the essential oil composition from Andean medicinal plants A. trifurcata, S. pogonias and S. oreophyton collected in central Andean slopes are reported for the first time.

Volatile Compounds in Thymus sect. Teucrioides (Lamiaceae): Intraspecific and Interspecific Diversity, Chemotaxonomic Significance and Exploitation Potential

Thymus sect. Teucrioides comprises three species, namely, T. hartvigii, T. leucospermus, and T. teucrioides, distributed in Greece and Albania. The volatile constituents of all species of the section were obtained by hydrodistillation and investigated by GC-FID and GC/MS analyses. Twenty populations were sampled and a total of 103 compounds were identified, representing 98.0-99.9% of the oil compositions. The oils were mainly characterized by high contents of monoterpene hydrocarbons (42.7-92.4%), with the exception of three oils for which oxygenated monoterpenes were the dominating constituents, viz., that of T. hartvigii ssp. macrocalyx, with linalool as main compound (89.2±0.5%), and those of T. hartvigii ssp. hartvigii and of one population of T. teucrioides ssp. candilicus, containing thymol as major component (46.4±3.1 and 38.2±3.9%, resp.). The most common compound in the oils of the 20 populations of the section was p-cymene. Considerable variation was detected within and among populations, and seven chemotypes were distinguished, i.e., p-cymene, linalool, p-cymene/thymol, p-cymene/γ-terpinene, p-cymene/borneol, p-cymene/γ-terpinene/borneol, and p-cymene/linalool chemotypes. Different chemotypes may exist in the same population. Multivariate statistical analyses enabled the segregation of the oils within Thymus sect. Teucrioides into two groups, one consisting of the three subspecies of T. teucrioides and the second comprising the species T. hartvigii and T. leucospermus. A linalool-rich chemotype, unique within the section, distinguished the oil of T. hartvigii ssp. macrocalyx from all other oils. The high oil content of p-cymene and the preference for serpentine substrates render T. teucrioides species promising for future exploitation.

Compositional Variations in Volatile Constituents of Boenninghausenia albiflora Reichb. from Western Himalaya

The essential-oil yield and composition of the aerial parts of Boenninghausenia albiflora were analyzed and compared by capillary GC-FID and GC–MS at different stages of growth and on drying prior to distillation. The essential-oil content of the aerial parts was found to vary from 0.15–0.20 % at different phenophases. Essential-oils were mainly composed of sesquiterpenoids (44.62–52.11 %) and monoterpenoids (25.73–45.95 %). Sesquiterpenoids (44.62–52.11 %) portion of essential-oils was represented by germacrene D (4.18–18.21 %), epi-α-cadinol (0.14–16.25 %), β-caryophyllene (4.62–13.14 %), globulol (0.26–9.22 %), and β-copaene-4α-ol (0.14–7.52 %); while β-myrcene (2.09–26.11 %) and β-pinene (8.36–13.77 %) were the major monoterpenoids. Variations in essential-oil yield (0.15–0.20 %), and contents of monoterpene hydrocarbons (19.38–42.59 %), sesquiterpene hydrocarbons (15.38–36.92 %) and oxygenated sesquiterpenes (9.97–36.73 %) due to different growth stages (vegetative, flowering and seed setting stages) of B. albiflora were noticed. On drying viz. sun and shade drying of the aerial parts of B. albiflora have no drastic influence on essential-ol quality; but significant quantitative variations were noticed. Further, variations in essential-oil composition of leaf and root essential-oils of B. albiflora collected from four different climatic locations were also compared.