Cyclic Monoterpenes Research Articles

Sulphite adducts of cyclic monoterpene ketones

Structures of sulphite addition products of some cyclic monoterpene ketones with Na 2SO 3 and/or NaHSO 3 were studied. The conjugated enones reacted with Na 2SO 3 and gave 1,4-addition products. The non-conjugated compounds did not react with Na 2SO 3. NaHSO 3 made radical additions to non-conjugated olefinic bonds. On the other hand, ketones having no olefinic bond did not form addition products. 1,4-addition products underwent a reverse reaction when alkali was added but the radical addition product was stable towards alkali and did not undergo reverse reaction.

Conversion of [1- 3H 2,G- 14C]geranyl pyrophosphate to cyclic monoterpenes without loss of tritium

Soluble enzyme preparations from Salvia officinalis convert the acyclic precursor [1- 3H 2,G- 14C]geranyl pyrophosphate to cyclic monoterpenes of the pinane (α-pinene,β-pinene), isocamphane (camphene), p-menthane (limonene,1,8-cineole), and bornane (bornyl pyrophosphate, determined as borneol) type without loss of tritium, and without significant conversion to other free acyclic intermediates. Similarly, [1- 3H 2,G- 14C]geraniol is converted in intact S. officinalis leaves to the cyclic monoterpene olefins and 1,8-cineole, as well as to isothujone and camphor, without loss of tritium from C(1). These results clearly eliminate transcis isomerization of geranyl pyrophosphate to neryl pyrophosphate via aldehyde intermediates prior to cyclization, and they support a scheme whereby the trans precursor is cyclized directly by way of a bound linaloyl intermediate.

Enhancement of the hydrolysis of geranyl pyrophosphate by bivalent metal ions. A model for enzymic biosynthesis of cyclic monoterpenes

Hydrolysis of geranyl pyrophosphate is catalyzed by salts of Mn 2+ and involves C-O bond cleavage. The first order rate constants reach limiting values with [Mn 2+] > 10 −2 M, and the most reactive species is GPP(Mn 2+) 2 at the optimum pH of 6.5–7. The products are similar to those from acid hydrolysis except that more cyclic hydrocarbons are formed in the presence of metal ions. Hydrolysis of geranyl phosphate is inhibited, and that of citronnellyl pyrophosphate is weakly catalyzed by Mn 2+. Other divalent metal cations catalyze the hydrolysis of geranyl pyrophosphate and the sequence of effectiveness is Cu 2+ > Mn 2+ > Zn 2+ > Co 2+ < Mg 2+ ~ Ca 2+.

Biosynthesis of monoterpenes: Hydrolysis of bornyl pyrophosphate, an essential step in camphor biosynthesis, and hydrolysis of geranyl pyrophosphate, the acyclic precursor of camphor, by enzymes from sage ( Salvia officinalis)

Soluble enzyme preparations from sage ( Salvia officinalis) leaves catalyze the hydrolysis of (+)-bornyl pyrophosphate to (+)-borneol, which is an essential step in the biosynthesis of the cyclic monoterpene (+)-camphor [(1 R,4 R)-bornan-2-one] in this tissue. Chromatography of the preparation on Sephadex G-150 allowed the separation of two regions of bornyl pyrophosphate hydrolase activity. One region was further separated into a pyrophosphate hydrolase and a monophosphate hydrolase by chromatography on hydroxylapatite, but the other contained pyrophosphate and monophosphate hydrolase activities which were inseparable by this or any other chromatographic technique tested. Each phosphatase and pyrophosphatase activity was characterized with respect to molecular weight, pH optimum, response to inhibitors, K m for bornyl phosphate or bornyl pyrophosphate, and substrate specificity, and each activity was distinctly different with regard to these properties. One pyrophosphatase activity was specific for pyrophosphate esters of sterically hindered monoterpenols such as bornyl pyrophosphate. The other preferred pyrophosphate esters of primary allylic alcohols such as geranyl pyrophosphate and neryl pyrophosphate, which are precursors of cyclic monoterpenes, and it hydrolyzed geranyl pyrophosphate at faster rates than neryl pyrophosphate. The monophosphate hydrolase activities were similar in substrate specificity, showing a preference for phosphate esters of primary allylic alcohols. The terpenyl pyrophosphate hydrolase exhibiting specificity for bornyl pyrophosphate may be involved in camphor biosynthesis in vivo, while the terpenyl pyrophosphate hydrolase more specific for geranyl pyrophosphate was shown to be a source of potential interference in studies on monoterpene cyclization processes.

Ochtodene and ochtodiol: novel polyhalogenated cyclic monoterpenes from the red seaweed Ochtodes secundiramea

Ochtodene and ochtodiol: novel polyhalogenated cyclic monoterpenes from the red seaweed Ochtodes secundiramea

A Study of Factors Affecting the Synthesis of Terpenes byCeratocystis Variospora

A defined basal medium for the production of essential oils by C. variospora was devised. The effect of different nitrogen sources on odor production and quality was studied. Carbohydrate and nitrogen utilization were followed and finally the production of the essential oil of C. variospora as a function of time was analyzed. Ceratocystis variospora (Davids.) C. Moreau is an ascomycete which produces a characteristic odor in culture. There is some confusion as to the validity of the species name, and Webster and Butler (1967) consider C. variospora synonymous with C. fimbriata Ell. & Halst. Ceratocystis variospora will be used to denote the organism in this report. The odorous compounds produced by C. variospora were studied by Collins and Halim (1970), and the following acyclic monoterpenes were identified: linalool, citronellyl acetate, neral, geranial, citronellol, geranyl acetate, and geraniol. Further work by Collins and Halim (1977) has shown the presence of the acyclic monoterpene nerol and the cyclic monoterpene a-terpineol. The purpose of this study was to examine some of those factors which might influence monoterpene production by this fungus as well as to follow terpene production during the growth period.

BIOSYNTHESIS OF CYCLIC MONOTERPENES IN HIGHER PLANTS. THE RETENTION OF THE C-5 HYDROGEN ATOMS OF MEVALONATE DURING ITS INCORPORATION INTO THE CYCLIC MONOTERPENES

Abstract The 3H/14C ratio of [5-3H2, 2- 14C]mevalonate was preserved in limonene, perillaldehyde, and camphor biosynthesized by higher plants from the mevalonate. This indicates that the cyclic monoterpenes are biosynthesized through such a pathway that involves the cyclization of such an intermediate as retaining all the C-1 and C-5 tritium atoms of geranyl pyrophosphate derived from the mevalonate.

ChemInform Abstract: THE REACTION OF 2‐FLUOROPYRIDINIUM SALT WITH NEROL AND GERANIOL. NON‐ENZYMIC BIOGENETICLIKE CYCLIZATION TO LIMONENE

AbstractNerol (I) liefert mit dem Fluorpyridiniumsalz (II) bei ‐40°C in Gegenwart von Tri‐n‐butylamin in Dichlormethan hauptsächlich Limonen (III), das auch bei der analogen Umsetzung von Geraniol (V) als Hauptprodukt entsteht.

THE REACTION OF 2-FLUOROPYRIDINIUM SALT WITH NEROL AND GERANIOL. NON-ENZYMIC BIOGENETICLIKE CYCLIZATION TO LIMONENE

Abstract Treatment of nerol with 2-fluoropyridinium salt and tri-n-butylamine at −40°C afforded cyclic monoterpenes, mainly limonene, in high yields. The reaction of geraniol with 2-fluoropyridinium salt is also described.

Biosynthesis of monoterpenes: Enzymatic conversion of neryl pyrophosphate to 1,8-cineole, α-terpineol, and cyclic monoterpene hydrocarbons by a cell-free preparation from sage ( Salvia officinalis)

The volatile oil of sage ( Salvia officinalis) leaf contains primarily cyclic monoterpenes, and a cell-free enzyme system prepared from immature sage leaves catalyzed the conversion of [1- 3H]neryl pyrophosphate to cyclic monoterpenes, including 1,8-cineole, α-terpineol, and limonene. The identity of these products was confirmed by the preparation of derivatives, chemical degradation studies, and radiochromatographic analyses. Enzymatic activity capable of 1,8-cineole and hydrocarbon formation was located primarily in the soluble fraction of the leaf homogenate, whereas activity responsible for α-terpineol formation, and phosphatase activity, was distributed among the soluble fraction and the 3000g particles. The formation of all cyclic products was stimulated in the presence of MnCl 2 (1–2 m m) and MgCl 2 (5–10 m m) and by inclusion of phosphatase inhibitors, such as NaF, in the incubation medium. Enzymatic activity increased linearly with protein concentration and time and was maximum at about pH 6.5. As α-terpineol could give rise to limonene by dehydration and yield 1,8-cineole by intramolecular attack of the hydroxyl at the double bond, the possible intermediary role of α-terpineol was examined. Inclusion of 1 m m (±)-α-terpineol in the incubation medium suppressed 1,8-cineole and hydrocarbon formation from neryl pyrophosphate by approximately 35%, suggesting that this alcohol could be an intermediate. However, the inhibition appeared to be nonspecific as several other monoterpene alcohols were similarly effective. In order to provide a more direct examination of the pathway, (±)-[3- 3H]α-terpineol was prepared and tested as a substrate with the enzyme system. (±)-[3- 3H]α-Terpineol was not converted to 1,8-cineole or to cyclic hydrocarbons, indicating that this alcohol was not an intermediate in the biosynthesis of the structurally related compounds. Furthermore, labeled α-terpineol was not incorporated into other monoterpenes in sage leaf slices, whereas the acyclic alcohols, [1- 3H]nerol and [1- 3H]geraniol, were readily incorporated into the characteristic cyclic monoterpenes of sage leaf. Similar lines of evidence excluded 1,8-cineole, limonene, and terpinolene as intermediates in the formation of cyclic products from neryl pyrophosphate. Thus, all of these results suggest that 1,8-cineole, α-terpineol, and limonene are derived independently from neryl pyrophosphate, rather than as free intermediates of a common reaction sequence. Additionally, this is the first report on the biosynthesis of 1,8-cineole in a cell-free system.

Plocamene B. New cyclic monoterpene skeleton from a red marine alga

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPlocamene B. New cyclic monoterpene skeleton from a red marine algaPhillip Crews and Ernest KhoCite this: J. Org. Chem. 1975, 40, 17, 2568–2570Publication Date (Print):August 1, 1975Publication History Published online1 May 2002Published inissue 1 August 1975https://doi.org/10.1021/jo00905a048RIGHTS & PERMISSIONSArticle Views78Altmetric-Citations30LEARN 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 (405 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Biosynthesis of Artemisia Ketone

MEVALONIC acid (MVA) is generally believed to be converted in higher plants into isopentenyl and 3,3-dimethylallyl pyrophosphates which in turn condense to form geranyl and neryl pyrophosphates, the presumed precursors of acyclic and cyclic monoterpenes respectively. Some of the individual steps have been demonstrated1–3; radioactive MVA has been incorporated without scrambling of tracer into several monoterpenes4–6; and the various classes of monoterpenes are thought to be biosynthesized from geranyl and neryl pyrophosphates by routes outlined by Ruzicka et al.7.

Biosynthesis of Monoterpenes in Rose Flowers

ALTHOUGH mevalonic acid (MVA) is generally assumed to be an obligatory precursor of terpenes in higher plants, incorporation of 2-14C-MVA into the principal monoterpenes of numerous species is almost invariably less than 1 per cent (ref. 1). Monoterpene biosynthesis is nevertheless assumed to occur via conversion of MVA into isopentenyl pyrophosphate (IPP) and 3,3-dimethyl-allylpyrophosphate (DMAPP) which condense to form, directly or in sequence, geranyl or neryl pyrophosphates (GPP and NPP), the presumed precursors of straight chain and cyclic monoterpenes respectively. More than 80 per cent of the total label from 2-14C-MVA, however, has been found to pass into that part of several thujane derivatives2, camphor3, pulegone4 and artemisia ketone4, and of certain sesquiterpenes5 also, which was derived from IPP. In only one example6 has a monoterpene, other than a methyl cyclopentanoid monoterpene, biosynthesized from 2-14C-MVA by a higher plant been shown to contain radioactivity comparably distributed between the moieties derived from IPP and DMAPP. All these experiments involved feeding leaf and stem tissue for 1–5 days, and less than 0.1 per cent of the applied tracer was incorporated during this period.

Rearrangements in the formation of some π-allylpalladium compounds

A reaction of p-menth-1 (2)-en-3-ol with palladium(II) chloride, lithium chloride, and carbon monoxide which was worked up as soon as the passage of gas had ceased gave di-µ-chloro-bis-[(1,2,3-trihapto-p-menth-1-ene)palladium(II)](2). When the mixture was set aside for several days di-µ-chloro-bis-[(3,4,8-trihapto-p-menth-3-ene)palladium(II)](3) was isolated. The preparation of (3) from other cyclic monoterpene derivatives is described.

Total synthesis of (±)-marmin and related coumarin monoterpenes

(±)-Marmin ( 1a) and its cis isomer ( 1b) have been synthesized from 7-neranyloxycoumarin ( 10a) and 7-neryloxycoumarin ( 10b), respectively, by way of the corresponding terminal epoxides 2a and 2a. The geometrically and positionally specific route confirms the structure and, in particular, the irons double bond geometry of natural (+)-marmin and epoxide (+)- 2a. The latter, upon reaction with stannic chloride in benzene gives rise to the naturally occurring cyclic monoterpene coumarin types 3 and 6 as well as the previously unknown double-bond isomer 13.

Terpene biosynthesis: Utilization of neryl pyrophosphate by an enzyme system from Pinus radiata seedlings

α pinene and β pinene (0.6%) are formed from 2- 14C neryl pyrophosphate by soluble enzymes from Pinus radiata seedlings. Geranyl pyrophosphate is much less active as a precursor of hydrocarbons and the monophosphates are completely inactive. These data offer further support to the proposed role of the cis isomer in the formation of cyclic monoterpenes.

Terpene biosynthesis: Formation of nerol, geraniol, and other prenols by an enzyme system from Pinus radiata seedlings

A soluble enzyme system obtained from Pinus radiata seedlings incorporates 6–7% of radioactivity from DL-2- 14C mevalonic acid into isopentenol, dimethyl allyl alcohol, nerol, and geraniol. The system requires Mg 2+ or Mn 2+, and SH groups for optimal activity. The C 5, and C 10 prenols are formed from the correspondent phosphorylated compounds by a phosphatase, which may be partially inhibited by NaF. About 1% of the radioactivity from mevalonic acid is found loosely bound to proteins. It may be extracted with 1-butanol and appears associated with C 15 prenols. Previous chemical evidence and some data in this paper suggest that neryl pyrophosphate and not geranyl pyrophosphate may be the precursor of cyclic monoterpenes.

Der stereochemische verlauf der alkalischen epoxydation von α,β-ungesättigten carbonylverbindungen der cyclischen monoterpenreihe

In the cyclic monoterpenes, the base-catalysed epoxidation 1 of endocyclic double bonds which are in conjugation with carbonyl groups follows a highly stereoselective course resulting in a single epimer. Exocyclic double bonds are attacked from both sides in this reaction. The hydrazine hydrate reaction of epoxycarbonyl compounds (Wharton and Bohlen 17) is also stereoselective resulting in allyl alcohols. The absolute configuration of the epoxycarbonyl compounds has been deduced from the endocyclic starting compounds.