Monoterpene Ether Research Articles

HS-SPME-GC/ MS analysis of 3lamiaceae plants: Ajuga iva (L.) Schreb., Salvia verbenacal.and Thymus algeriensisboiss. & Reut.

The chemical analysis of three Algerian plants was conducted by using Headspace Solid Phase Micro Extraction coupled with Gas Chromatogr aphy Mass Spectrometry (HS SPME GC/ MS). This analysis was performed directly on the dried aerial parts of the plants. The results revealed that the major compounds are 1,8 cineol (27.3%) in Ajuga iva, cis-muurola-3,5 diene (14.6%) in Salvia verbenaca and 2,3-dehydro 1,4-cineol (36%) in Thymus algeriensis . The oxygenated monoterpenes are the major class representing 62.1% and 78.4% in Ajuga iva and Thymus a lgeriensis , respectively, whereas the sesquiterpene hydrocarbons are the major class in Salvia verbena ca representing 50.1%. Identification of naturally rare monoterpene ether, 2,3-dehydro 1,4-cineol was the first time in the Ajuga iva Salvia verbenaca and Thymus algeriensis.

Distinct Fractions of an Artemisia scoparia Extract Contain Compounds With Novel Adipogenic Bioactivity.

Adipocytes are important players in metabolic health and disease, and disruption of adipocyte development or function contributes to metabolic dysregulation. Hence, adipocytes are significant targets for therapeutic intervention in obesity and metabolic syndrome. Plants have long been sources for bioactive compounds and drugs. In previous studies, we screened botanical extracts for effects on adipogenesis in vitro and discovered that an ethanolic extract of Artemisia scoparia (SCO) could promote adipocyte differentiation. To follow up on these studies, we have used various separation methods to identify the compound(s) responsible for SCO's adipogenic properties. Fractions and subfractions of SCO were tested for effects on lipid accumulation and adipogenic gene expression in differentiating 3T3-L1 adipocytes. Fractions were also analyzed by Ultra Performance Liquid Chromatography- Mass Spectrometry (UPLC-MS), and resulting peaks were putatively identified through high resolution, high mass accuracy mass spectrometry, literature data, and available natural products databases. The inactive fractions contained mostly quercetin derivatives and chlorogenates, including chlorogenic acid and 3,5-dicaffeoylquinic acid, which had no effects on adipogenesis when tested individually, thus ruling them out as pro-adipogenic bioactives in SCO. Based on these studies we have putatively identified the principal constituents in SCO fractions and subfractions that promoted adipocyte development and fat cell gene expression as prenylated coumaric acids, coumarin monoterpene ethers, 6-demethoxycapillarisin and two polymethoxyflavones.

Essential oil composition of three accessions of Dracocephalum heterophyllum Benth. cultivated at Palampur, India

Seeds of three accessions of Dracocephalum heterophyllum growing wild in high altitude locations in the cold desert regions of trans-Himalaya were collected and propagated under polyhouse conditions at IHBT Palampur to evaluate, compare their growth performance and essential oil composition. Three different chemotypes viz., citronellol-rose oxides type, citronellol type and citronellal-trans rose oxide type were identified. Samples of essential oils were distilled separately from leaves and inflorescence of all the three cultivated accessions and characterised by capillary GC and GC–MS techniques, which showed variation in the volatile constituents. In all the three accessions, citronellol was higher in the inflorescence oils as compared to leaf oils. Rose oxides, which are important high odour value cyclic monoterpene ethers were found in the essential oil samples of leaves as well as in the inflorescence of accession II, whereas these constituents were absent in the leaves of other two accessions. The essential oil from the inflorescence part of accession I was devoid of both cis and trans isomers of rose oxide, while accession III contained only one isomer of trans rose oxide. Under polyhouse conditions, seed germination was higher in accession III, whereas aerial biomass was higher in accession I. In comparison to other accessions, yield of volatile oil was higher in both leaf and inflorescence of accessions I, whereas accession II had higher oil yield from inflorescence. This is the first report of volatile oil composition of three accessions of D. heterophyllum cultivated at Palampur having potential as a new source of high valued essential oil for introduction in the perfumery industry.

Synthesis of Artekeiskeanin A: A New Coumarin Monoterpene Ether from Artemisia keiskeana

The first total syntheses of artekeiskeanin A, a natural coumarin monoterpene ether from Artemisia keiskeana, and 7-geranyloxy-6-methoxycoumarin, a coumarin monoterpene ether with antifungal and antitumor properties, are reported. Key step in the synthesis of artekeiskeanin A is the stereoselective oxidation of the geranyloxy side chain of 7-geranyloxy-6-methoxycoumarin under microwave irradiation.

Four new coumarin derivatives from Artemisia keiskeana.

Four new coumarin monoterpene ethers, artekeiskeanols A-D (1-4), and three known coumarins, isofraxidin, fraxidin, and daphnoretin, were isolated from the whole plants of Artemisia keiskeana. All structures were determined from spectral data, and that of artekeiskeanol A (1) was confirmed by synthesis.

Influence of temperature on the rhythmic emission of volatiles from Ribes nigrum flowers in situ

ABSTRACTThe floral volatiles of blackcurrant (Ribes nigrum) were collected in situ using the headspace technique. Eleven compounds were identified, including monoterpenes hydrocarbons and monoterpene ethers. The fragrance was emitted in a rhythmic manner, the maximum being in the middle of the photoperiod. Emission at 20°C was significantly higher than at 10°C. The rhythmic nature of emission seemed to cease under conditions of constant light. However, a slight rise in emission during the second period in continuous light may indicate a circadian control of emission. The significance of flower volatiles in relation to pollination is discussed.

Biosynthesis of Monoterpenes: Partial Purification, Characterization, and Mechanism of Action of 1,8-Cineole Synthase

Geranyl pyrophosphate:1,8-cineole cyclase (cineole synthase) catalyzes the conversion of geranyl pyrophosphate to the symmetrical monoterpene ether 1,8-cineole (1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane) by a process thought to involve the initial isomerization of the substrate to the tertiary allylic isomer, linalyl pyrophosphate, and cyclization of this bound intermediate to the α-terpinyl carbocation that is subsequently captured by water and undergoes heterocyclization to the remaining double bond. The enzyme was isolated from the secretory cells of the glandular trichomes of Salvia officinalis (garden sage) and partially purified, and the properties of this monoterpene cyclase, previously determined in crude cell-free extracts, were reexamined. These properties (pH optimum, divalent metal ion requirement, molecular weight, pI) were similar to those determined previously with the exception of substrate utilization; geranyl pyrophosphate was shown to be a more efficient substrate than the cis-isomer, neryl pyrophosphate, in the absence of competing phosphatase activity that contaminated earlier preparations of this enzyme. As with other monoterpene cyclases of herbaceous species, cineole synthase was inhibited by cysteine- and histidine-directed reagents, and protection against inactivation was provided by the substrate-metal ion complex. Studies with 18O-labeled acyclic precursors and H 2 18O, followed by mass spectrometric analysis of the product, confirmed that water was the sole source of the ether oxygen atom of 1,8-cineole. The electrophilic nature of the coupled isomerization-cyclization reaction was examined with a series of substrate and intermediate analogues. The overall stereochemistry of the cyclization of geranyl pyrophosphate to the symmetrical monoterpene was established by determining the enantioselectivity for (3 R)- or (3 S)-linalyl pyrophosphate as an alternative substrate and by oxidation of [3- 3H]1,8-cineole, derived from [1- 3H]geranyl pyrophosphate, to (±)-3-keto-1,8-cineole and radio-GLC separation of diastereomeric ketal derivatives to determine the labeled enantiomer.

Biotransformation of 1,4-cineole, a monoterpene ether.

1. The metabolism of 1,4-cineole, a monoterpene ether, was studied in the rabbit. 2. Four neutral and one acidic metabolites were isolated from the urine and shown to be 9-hydroxy-1,4-cineole, 3,8-dihydroxy-1,4-cineole, 8,9-dihydroxy-1,4-cineole, 1,4-cineole-8-en-9-ol and 1,4-cineole-9-carboxylic acid.

ChemInform Abstract: Regiospecific Functionalization of the Monoterpene Ether 1,3,3‐Trimethyl‐2‐oxabicyclo(2.2.2)octane (1,8‐Cineole). Synthesis of the Useful Bridged γ‐Lactone 1,3‐Dimethyl‐2‐oxabicyclo(2.2.2)octan‐3→5‐olide.

AbstractChromyl acetate oxidation of the oxabicyclooctane (I) gives the ketone (II) as the main product, together with the six by‐products (III) ‐ (VIII).

Regiospecific functionalization of the monoterpene ether 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane (1,8-cineole). Synthesis of the useful bridged .gamma.-lactone 1,3-dimethyl-2-oxabicyclo[2.2.2]octan-3 .fwdarw. 5-olide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegiospecific functionalization of the monoterpene ether 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane (1,8-cineole). Synthesis of the useful bridged .gamma.-lactone 1,3-dimethyl-2-oxabicyclo[2.2.2]octan-3 .fwdarw. 5-olideMargarita V. De Boggiatto, Carola S. De Heluani, Ines J. S. De Fenik, and Cesar A. N. CatalanCite this: J. Org. Chem. 1987, 52, 8, 1505–1511Publication Date (Print):April 1, 1987Publication History Published online1 May 2002Published inissue 1 April 1987https://doi.org/10.1021/jo00384a023RIGHTS & PERMISSIONSArticle Views594Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1010 KB) Get e-Alerts Get e-Alerts

Synthesis of dehydrocineole, a new monoterpene from the acarid mite, [formula omitted][formula omitted] (arachnida: acari)

Dehydrocineole, a new monoterpene ether, 6-methylsalicylaldehyde, undecane and tridecane are reported from the opisthonotal gland secretion of the mite, Caloglyphus rodriguezi . A synthesis of dehydrocineole is described.

The absolute stereochemistry and corrected structure of the monoterpene ether from [formula omitted][formula omitted

The absolute stereochemistry and corrected structure of the monoterpene ether from [formula omitted][formula omitted