Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Monocyclic monoterpene

Terpenes are a class of naturally occurring olefins found in many plants. They are biosynthetically derived from isoprene, CsHg, and therefore consist of Cs-building blocks and are found in both cyclic and acyclic forms. An important subgroup is the monoterpenes, which consist of two isoprene units and are of the molecular formula Ci0H16. Of the monocyclic monoterpenes, by far the most industrially relevant is limonene, which is abundantly present as a fragrance in various household products. From the bicyclic monoterpenes, a-pinene, p-pinene, camphene, and carene are of industrial relevance and are also mostly used in the fragrance industry [44]. [Pg.138]

Figure 3.9 Ketones. /-Carvone (C10H140), a monocyclic monoterpene ketone. Courtesy Spiring Enterprises Ltd. Figure 3.9 Ketones. /-Carvone (C10H140), a monocyclic monoterpene ketone. Courtesy Spiring Enterprises Ltd.
Monocyclic monoterpenes include the fully saturated menthol (5-methyl-2-isopropyl-cyclohexanol) (C6) (peppermint smell), the fully unsaturated analogue thymol (5-methyl-2-isopropylphenol) (G6) (smell of thyme) and the partially unsaturated a-terpinene (5,6-dihydro-4-isopropyltoluene) (G6) (lemon odour). Variants derive from different degrees of unsaturation and substitution and from different functional groups (e.g. alkyl, hydroxyl, aldehyde, peroxy and keto groups). [Pg.35]

Monocyclic monoterpene hydrocarbons occur in many essential oils and their by-products. They have relatively weak odours, although some add dryness and green notes to the oils containing them. This is particularly so for lime and petitgrain. D-Limonene (1) occurs in citrus oils whereas the L-isomer is found in pine. If limonene or other terpenes break down during processing to produce isoprene, then racemic limonene, dipentene, is found in the product as a result of the Diels-Alder reaction. Terpinolene (2) is the dehydration product of a-terpineol and so it is often present as an artefact. a-Phellandrene (3) occurs in eucalyptus oil. Since it is a 1,3-diene, it is an obvious precursor for Diels-Alder reactions and a number of speciality ingredients are... [Pg.69]

Monocyclic monoterpene ketone monooxygenase Rhodococcus erythropolis DCL 14 1 single polypeptide NADPH 60 FAD 9.0 [51]... [Pg.1215]

Before 1960, one of main components of olive, the oleuropein, was studied in Roma. Panizzi s research group established the structure of this monoterpene glucoside, die leader of the group, that only several years later was identified as secoiridoids. Panizzi s group has isolated two other compounds the oleuropeic acid that is a monocyclic monoterpene, and its saccharose derivative. [Pg.861]

Monocyclic monoterpenes, such as (+)-limonene, are abundant natural products and are a major product of the oils of citrus fruit peels. (+)-Limonene (Figure 45) is reported to be chemopreventive in rodents against spontaneous and chemically induced tumors [154,155]. [Pg.461]

Okabe, H., Obata, Y, Takayama, K., and Nagai, T. (1990). Percutaneous absorption promoting effect and skin irritancy of monocyclic monoterpenes. Drug. Des. Deliv, 6 229-238. [Pg.245]

Menaquinone, menadione see vitamin K]. p-Menthadienes. Doubly unsaturated, monocyclic monoterpenes derived from p-menthane. C,oH 6, Mr 136.23, liquids, sensitive to light, air, and heat. Occurrence p-M. are widely distributed in nature. The table (see below) lists those plants from which laiger amounts of p-M. can be isolated from the essential oils. /S-Terpinene and (-)-j8-phellandrene occur in very small amounts only. [Pg.389]

CioHjo, Mr 140.27, liquid with a fennel-like odor. A monocyclic monoterpene, bp. rrtww-form 170.6 C, c -form 172 °C. p-M. occurs in the essential oils of the Asian plants Gardenia taitensis (Rutaceae), Syzygium cuminii (Myrtaceae), and Hibiscus syriacus (Malvaceae), detected by GC/MS only. [Pg.389]

Perllla alcohol [4-(l-methylethenyl)-l-cyclohexene-1-methanol]. Formula, see perillaldehyde. CiqHi O, Mr 152.24, oil. A monocyclic monoterpene alcohol occurring in both enantiomeric forms (/ )(+)- and (5)(-)-P bp. 119-121 °C (1.1 kPa), [a]o 68°. (-H)-P. occurs in delft grass oil Cymbopogon polyneu-ros, Poaceae) a grass indigenous to the Nilgiri mountains (Southern India) and the mountains of Sri Lanka (- )-P. occurs in false lavender oil Lavandula hybrida, Lamiaceae). For synthesis, see Lit.. P. induces apoptosis. It is in clinical development against breast and prostate cancer. [Pg.475]

C10H14O, Mr 150.22, oil. Monocyclic monoterpene aldehyde occurring in both enantiomeric forms (/ )-(- )- and(S)-(-)-P.,bp. 104°C(900 Pa), [o]d 150.7°. LD50 (rat p. 0.) 2500 mg/kg. (-)-P. constitutes ca. 50% of Perilla oil from Perilla arguta and P. frutescens var. crispa (Lamiaceae), (+)-P. constitutes ca. 60% of the Philippine Sulpicia oil from Sulpicia orsuami and also occurs in Siler trilobum, Siam latifolium. Citrus reticulata, and other plants. The ( )-oxime of (5)-(-)-P. is used in Japan as a sweetener Perilla sugar and has a 2000-fold higher sweetness than saccharose. [Pg.475]

C,oH,40, Mr 150.22, bp. 72 C (4 hPa). A monocyclic monoterpene aldehyde. S. is the odor principle of saffron and is formed from the bitter saffron gluco-side picrocrocin [CisHjjO, Mr 330.38, mp. 156°C, [a]g -58° (H2O)]. S. acts as an androtermone, i.e., the substance determining the male gender of the green alga Chlamydomonas eugametus. S. occurs in saffron oil (Crocus sativus, Iridaceae) and is prepared from, e.g., citral. ... [Pg.565]

C10H20O2, Mr 172.27. A monocyclic monoterpene dialcohol with the p-menthane structure occurring in nature in both the trans- and the c/s-forms, "trans-T. , mp. 158-159°C, c -T. ,mp. 104-105°C.The a5-T. exists mostly as the hydrate ( c -terpin hydrate , mp. 118 -119 °C) which is used as an expectorant. The occurrence of T. is probably the result of secondary formation from y-terpineol menth-4(8)-en-l-ol]. T. occurs in Chinese star anise oil (Illicium venim, Illi-ciaceae). For synthesis, see Ut.. ... [Pg.639]

Thujaplicins. CiqHijOj, Mr 164.20, colorless crystals. Monocyclic monoterpenes with the tropolone structure (2-hydroxy-2,4,6-cycloheptatrien-l-one) thatdif-... [Pg.651]

The biogeneses of cyclic and polycyclic terpenes are usually assumed to involve intermediate carbenium ions, but evidence for this in vivo was given only in some specific cases. In the simple case of monocyclic monoterpenes such as limonene the allylic cation remaining after separation of the pyrophosphate anion cyclizes to a cyclohexyl cation which is deprotonated to (/ )- or (5)-limonene. [Pg.6]

For illustration of the isoprene rule, isoprene units of acyclic and monocyclic monoterpenes are printed in boldface. [Pg.185]

Monocyclic monoterpenes p-menthane in essential oils, e.g. eucalyptus fruits typical odor (fennel)... [Pg.99]

The co-occurrence in many plant species of structurally related monocyclic monoterpenes, such as limonene, terpinolene, and a-terpineol, raises an important question as to whether these compounds arise independently from an acyclic prenyl pyrophosphate precursor or whether such monoterpenes may be formed by sequential modification of a single monocyclic intermediate, such as a-terpineol (Croteau et al., 1973). Cell-free extracts capable of converting acyclic precursors to a-terpineol (Croteau et al., 1973) and to limonene (George-Nascimento and Cori, 1971 Chayet et al., 1977) are available, but until a cell-free system capable of synthesizing several structurally related compounds was obtained, the question of sequential or independent formation could not be resolved. A soluble enzyme preparation from sage leaves was shown to catalyze the conversion of NPP to a number of cyclic monoterpenes, including limonene, terpinolene, a-terpineol, and... [Pg.376]

The substrate specificity of 1,8-cineole, a-terpineol, limonene, and terpin-olene synthetases from sage has not yet been determined however, it is quite clear that the sage preparations, and similar preparations from Citrus (George-Nascimento and Cori, 1971 Chayet et al., 1977), can utilize both GPP and NPP for the biosynthesis of monocyclic monoterpenes. Only when such cell-free preparations are free of all competing enzyme activities can the true specificities of the monoterpene synthetases be accurately determined. [Pg.377]

Extensive groups of oxygen-containing, monocyclic monoterpenes are derived from the p-M. [Pg.398]


See other pages where Monocyclic monoterpene is mentioned: [Pg.6]    [Pg.50]    [Pg.50]    [Pg.97]    [Pg.186]    [Pg.106]    [Pg.1534]    [Pg.173]    [Pg.14]    [Pg.118]    [Pg.118]    [Pg.493]    [Pg.87]    [Pg.279]    [Pg.168]    [Pg.390]    [Pg.13]    [Pg.13]    [Pg.15]    [Pg.17]    [Pg.363]    [Pg.376]    [Pg.377]    [Pg.378]    [Pg.391]    [Pg.123]    [Pg.397]   
See also in sourсe #XX -- [ Pg.35 ]




SEARCH



Monocyclic

Monocyclic monoterpene alcohol

Monocyclic monoterpene aldehyde

Monocyclic monoterpene hydrocarbon

Monocyclic monoterpene ketone

Monoterpenals

Monoterpene

Monoterpenes

Monoterpenes monocyclic

Monoterpenes monocyclic

© 2024 chempedia.info