Showing papers on "Terpene published in 1985"

Microbial transformations of some monoterpenoids and sesquiterpenoids.

Abstract: The absolute configurations of fragrances, flavours and drugs are often important for their special properties. The growing interest of organic chemists in chiral synthons has stimulated work on biotransformations, for which readily available and inexpensive compounds can be used as substrates. Microbial transformations of 1-menthenes like gamma-terpinene, alpha-terpinene, limonene and alpha-phellandrene give the corresponding 1,2-trans-diols with high stereospecificity. Because of the volatility and toxicity of these substrates, and their low solubility in aqueous solutions, a special fermentation technique has been developed in which the terpenes are fed continuously to extended cultures of Corynespora cassiicola or Diplodia gossypina. (4R)-Limonene is transformed by Gibberella cyanea to (1S,2S,4R)-p-menth-8-en-1,2-diol, but 3,3,5,5-tetramethyl-limonene yields a 6-monohydroxylated product and a 6,10-dihydroxylated product with a 6-hydroxy-8,10-epoxy structure as the main metabolite. Vicinal diols are also formed from aliphatic terpenes, by reaction at the terminal isoprenoid groups. Some oxirane structures are found as intermediates. Acyclic sesquiterpenes often form complex mixtures when they are metabolized further. The products of the transformation of trans-nerolidol by several fungi are given as examples. Cyclic sesquiterpenes, with less flexible structures, are oxidized more specifically. Whereas longifolene is a very poor substrate for Corynespora cassiicola, isolongifolene is always hydroxylated at one of the methyl groups attached to C-7. The 14- or 15-hydroxy compounds are further oxidized, very fast, in the 3 position or 4 position.

Isomerization of unsaturated terpenes via allylstannanes: a new short synthesis of (+)-β-pinene from (+)-α-pinene

Abstract: A two-step isomerization of unsaturated terpenes via allyltin compounds is reported, by which route(+)-α-pinene has been converted into (+)-β-pinene in 50% yield.

[Aroma of the papaya fruit (Carica papaya, L.): indication of volatile precursors of terpene compounds].

Abstract: In fruit pulp of papaya (Carica papaya, L.) the enzymes were inhibited by Hg2+. These sample were compared with others, in which the enzymes had not been inhibited. After separation and prefractionation of volatiles by means of high vacuum distillation/solvent extraction and subsequent adsorption chromatography on silicagel, capillary gas chromatography-mass spectrometry showed that in the experiment with Hg2+ the formation of terpene alcohols and hydrocarbons as well as benzylisothiocyanate was totally inhibited. The formation of linalooloxides and related compounds was inhibited to about 60%. From these results the occurrence of bound terpene precursors in papaya fruit may be postulated, from which the free volatile terpenes are enzymatically liberated after decompartmentalization of tissue during fruit pulp preparation.

The leaf oil terpene composition of eastern white pine, Pinus strobus L

Abstract: Analysis by an on-line computerized gas-chromatrographic (g.c.)-mass spectral method of the steam-volatile leaf oil of eastern white pine confirmed that α- and β-pinene, and myrcene are the main monoterpenes, with lesser amounts of camphene, car-3-ene, β-phellandrene, limonene, terpinolene, α-terpineol, and bornyl acetate. In addition, germacrene-D and caryophyllene were identified as the main sesquiterpenes; lesser amounts of humulene and δ-cadinene were also found. Small or trace amounts of hexanal, hex-2-enal, tricyclene, o-cymene, α-phellandrene, α-terpinene, p-cymene, γ-terpinene, α-fenchol, pinocamphone, terpinen-4-ol, a cadinol isomer, manoyl oxide, and a kauranol isomer were identified. Germacrene-D tended to rearrange to other sesquiterpenes on all but highly deactivated g.c. columns.

Additive for cold permanent wave lotion

Abstract: PURPOSE:To provide the titled additive which is an aqueous solution containing terpenes as main active deodorizing component, and is effective to actively deodorize the ill odor of cold permanent wave lotion without masking the odor with the smell of perfumery, etc. CONSTITUTION:Terpenes used mainly as raw materials of perfumery, preferably citral, limonene, cedrol, cineole (eucalyptus oil), etc. are used as the main deodorizing components of the objective additive. The additive is used preferably in the form of an aqueous emulsion, and the concentration of the terpene in the emulsion is preferably about 30-45% when terpene is used singly. The additive may be incorporated further with camphor oil, eucalyptus oil, etc. at a concentration of about 5-20wt%. EFFECT:It utilizes the deodorizing activities of terpenes, i.e. the molecular adsorptivity of terpene and the activity of terpene vapor to encapsulate the odorous fine particles.

Novel terpene derived functional silanes

Abstract: Novel epoxyterpenylsilanes containing chiral centers have been prepared in a two-step synthesis. Terpenes, such as myrcene, dihydromyrcene, limonene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene; are first epoxidized to the terpene oxide which is then condensed with alkoxy or alkylalkoxysilanes in the presence of a hydrosilation catalyst.

Stabilising dentifrices containing aldehyde flavours

Abstract: Dentifrices with stability against discolouration upon aging contain as flavouring agent cinnamic aldehyde or citral and 0.1-5% of (1) a terpene or sesquiterpene colour stabilizer with trisubstituted double bonds e.g. limonene, ocimene, caryophyllene, citrus oils, clove sesquiterpenes, myrcene, terpene derivatives, citronellyl acetate or (2) propylene glycol or dipropylene glycol in a dental vehicle of pH below 8.5 and free of oxidizing agents.

Synthetic studies on the ochtodane type terpenes. i. stereoselective construction of the ochtodane skeleton from myrcene

Abstract: The ochtodane skeleton, the Carbon framework of 1,1-dimethyl-3-ethylcyclohexane (1) was constructed highly stereoselectively by the acid-catalyzed (SnCl4 or CF3CO2H) cyclization of the terminally functionalized myrcene derivatives, the benzenesulfenyl chloride adduct (7), the terminal β-hydroxy sulfide (8) derived from 7, and myrcene 6,7-epoxide (10). The stereoselectivity of the 3-exo-double bond in 1 formed concomitantly in the cyclization reaction was found to depend remarkably upon the reaction temperature and the 85–94% of E-stereoselectivity was attained at −78 °C. By the method, the ochtodane derivatives with the sulfur- or oxygen-functional groups on the C(6)-position were obtained. Synthetic applications of the ochtodane type compounds (12) and (19) to the aldehyde component (4) of the pheromone of the male boll weevils and to an ochtodane type terpene (26) isolated from the red alga Octodes crockeri, are reported.

ISOMERIZATION OF UNSATURATED TERPENES VIA ALLYLSTANNANES: A NEW SHORT SYNTHESIS OF (+)-β-PINENE FROM (+)-α-PINENE

Abstract: A two-step isomerization of unsaturated terpenes via allyltin compounds is reported, by which route(+)-α-pinene has been converted into (+)-β-pinene in 50% yield.