Search results for "monoterpene"
showing 10 items of 145 documents
Structure of Rhodococcus erythropolis limonene-1,2-epoxide hydrolase reveals a novel active site
2003
Epoxide hydrolases are essential for the processing of epoxide-containing compounds in detoxification or metabolism. The classic epoxide hydrolases have an alpha/beta hydrolase fold and act via a two-step reaction mechanism including an enzyme-substrate intermediate. We report here the structure of the limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis, solved using single-wavelength anomalous dispersion from a selenomethionine-substituted protein and refined at 1.2 A resolution. This enzyme represents a completely different structure and a novel one-step mechanism. The fold features a highly curved six-stranded mixed beta-sheet, with four alpha-helices packed onto it to create a …
The essential oil of turpentine and its major volatile fraction (alpha- and beta-pinenes): a review.
2010
This paper provides a summary review of the major biological features concerning the essential oil of turpentine, its origin and use in traditional and modern medicine. More precisely, the safety of this volatile fraction to human health, and the medical, biological and environmental effects of the two major compounds of this fraction (alpha- and beta-pinenes) have been discussed.
Artemisia arborescens L.: essential oil composition and effects of plant growth stage in some genotypes from Sicily
2012
Essential oils from aerial parts of several Artemisia arborescens L. populations, collected in five different localities of Sicily, were analyzed by gas chromatograph–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS) in order to study the chemical composition and its variability due to phenological stage. Forty-three compounds, accounting for more than 92% of the oil, were identified. Monoterpene fraction with the exception of Petru population was higher than the sesquiterpene fraction. β-Thujone (20.5–55.9%), chamazulene (15.2–49.4%), camphor (1.3–10.7%) and germacrene D (2.3–3.4%) were the main compounds. Chemical composition was influenced by phenological stage, with an…
2-exo,5-endo,8,8,10-Pentachlorobornane
2008
The title compound, C(10)H(13)Cl(5), is a polychlorinated monoterpene and a Toxaphene congener. This compound is also the only penta-chlorinated derivative of camphene formed via ionic chlorination. Previously, the title compound was thought to be 2-exo,5-endo,9,9,10-penta-chloro-bornane, but X-ray structural analysis showed it to have a different structure and rather to be 2-exo,5-endo,8,8,10-penta-chloro-bornane. The title compound shows static disorder and almost half the molecule was divided in two partitions with an occupancy ratio of 0.575 (major) to 0.425 (minor). The repulsive close contacts of Cl atoms could possibly be the cause for this disorder.
Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines
2014
Starting from pinane-, apopinane- and carane-based 1,3-amino alcohols obtained from monoterpene-based β-amino acids, a library of monoterpene-fused 2-imino-1,3-thiazines as main products and 2-thioxo-1,3-oxazines as side-products were prepared via two- or three-step syntheses. When thiourea adducts prepared from 1,3-amino alcohols and aryl isothiocyanates were reacted with CDI under mild conditions, O-imidazolylcarbonyl intermediates were isolated which could be transformed to the desired 1,3-thiazines under microwave conditions. 1,3-Thiazines and 2-thioxo-1,3-oxazine side-products could also be prepared in one-step reactions through the application of CDI and microwave irradiation. The rin…
The Antigerminative Activity of Twenty-Seven Monoterpenes
2010
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Wild Sicilian Rosemary: Phytochemical and Morphological Screening and Antioxidant Activity Evaluation of Extracts and Essential Oils
2015
To identify the best biotypes, an extensive survey of Sicilian wild rosemary was carried out by collecting 57 samples from various sites, followed by taxonomic characterization from an agronomic perspective. All the biotypes collected were classified as Rosmarinus officinalis L. A cluster analysis based on the morphological characteristics of the plants allowed the division of the biotypes into seven main groups, although the characteristics examined were found to be highly similar and not area-dependent. Moreover, all samples were analyzed for their phytochemical content, applying an extraction protocol to obtain the nonvolatile components and hydrodistillation to collect the essential oil…
Essential oil variation within and among natural populations of Lavandula latifolia and its relation to their ecological areas
2007
Essential oil yield and composition in seven natural populations of Lavandula latifolia from the eastern Iberian Peninsula were determined by GC/MS. Twenty-eight constituents were identified, accounting for 92.0e95.4% of the total oils. These oils were dominated by the monoterpene fraction and three of them (linalool, cineole and camphor) constituted 79.5e86.9% of the oil from flowers. Essential oil yield in leaves and flowers varied among and within populations, but hierarchic analyses of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Principal component and cluster analyses allowed thr…
Volatile constituents of the aerial parts of Pulicaria sicula (L.) Moris growing wild in Sicily: Chemotaxonomic volatile markers of the genus Pulicar…
2015
Abstract 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 princi…
Hydrocarbon chemotypes of some blackcurrant cultivars (Ribes sp)
1989
The hydrocarbon fractions of the essential oils of 11 cultivars of blackcurrant (Ribes spp) buds originating from collections in France and Australia have been submitted to GC/MS analysis. The major monoterpene and sesquiterpene hydrocarbons define chemotypes which have been conventionally described by a letter-based formula. Whereas four monoterpene chemotypes previously reported are confirmed, eight sesquiterpene chemotypes have to be redefined. They involve: δ-elemene, β-caryophyllene, γ-elemene, α-humuiene, alloaromadrene, germacrene D, γ-cadinene, and two unknowns. The different cultivars examined and their corresponding chemotypic formulae have been discriminated by principal componen…