Cymene

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cymene

[′sī‚mēn]
(organic chemistry)
Any of the isomeric hydrocarbons metacymene, paracymene, and orthocymene; paracymene is a liquid that is colorless, has a pleasant odor, and is made from oil of cumin or oil of wild thyme.

Cymene

 

(also methyl-isopropyl-benzene), an aromatic hydrocarbon having the structural formula

The meta-, ortho-, and para-isomers of cymene are known; the most important is para-cymene, which is a component of turpentine and many essential oils, including cumin oil and eucalyptus oil. A colorless liquid with a characteristic odor, para-cymene has a boiling point of 177.1°C, a melting point of –67.9°C, and a density of 0.857 g/cm3 at 20°C. Cymene is insoluble in water, but it is miscible with many organic solvents.

The similarity of the carbon skeleton of para-cymene with the skeletons of many cyclic terpenes is a result of their common origin. Thus, para-cymene may be produced by the pyrolysis of α-pinene, the dehydrogenation of limonene, or the heating of camphor with P2O5. In the chemical industry, para-cymene is produced from sulfite turpentine and is used as a raw material and a solvent.

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In the rainy season, plant 1 presented carvacrol as the main compound (71.9 %) and a lower content of p-cymene (18.4 %), when compared to the dry season.
The activity of some EOs, such as those with p-cymene, thymol, and citral at high concentrations, is associated with their capacity to cause structural and functional changes in the cytoplasmic membrane, resulting in the reduction of membrane potential and the loss of ATP and ions, in addition to possible interactions with intracellular targets.
Our results are in agreement with those obtained by Skocibusic and Bezic 2004 [21] that identified carvacrol (45.7%) as the major component followed by the monoterpenic hydrocarbons p-cymene (12.6%), [gamma]-terpinene (8.1%), borneol, thymol, and thymol methyl ether.
The composition of EOLs determined by this method were: thymol (66.00%), p-Cymene (15.01%), caryophyllene (4.60%), myrcene (4.23%), gamma-terpinene (1.87%), thymylethyl-ether (1.15%), and alfa-terpinene (1.01%).
Cavalcanti et al., "P-Cymene reduces orofacial nociceptive response in mice," Revista Brasileira de Farmacognosia, vol.
Comparing the EOPh composition with literature data, it was noticed that, generally, phellandrenes, terpinolenes, limonenes, oxidized p-menth-3-ene-1,2,8-triol, and aromatized p-cymene are major constituents of the essential oil of P.
The most dominant constituents of the ground seeds were observed hierarchically to be p-cymene, 2-thujene, thymoquinone, longifolene, carvacrol, and carvone.
Other compounds detected in the oregano oil included p-cymene (8.5%) and [gamma]-terpinene (6.4%).
Therefore, the objective of the present study was to evaluate the effects of 11 ACEO (eugenol, carvacrol, citral, limonene, 1,4-cineole, p-cymene, linalool, bornyl acetate, [alpha]-pinene, and [beta]-pinene) on rumen fermentation and methane production.
The base gasoline was obtained from a local supplier, and oxygenates were obtained as reagent grade chemicals, p-Xylene (1,4-dimethylbenzene) and p-cymene (1-methyl, 4-isopropylbenzene) were used to increase the base gasoline RON and PMI without adding oxygen.