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Characteristics Of The GC-MS Mass Spectra Of Terpenoids (C10H16)

Abstract

Alexander I Yermakov, *Abdelaziz L Khlaifat, Hani Qutob, Rimma A Abramovich, Yuri Y Khomyakov

The terpenoids, sometimes referred to as isoprenoids, are a large and diverse class of naturally occurring organic chemicals similar to terpenes, derived from five-carbon isoprene units assembled and modified in thousands of ways. Most are multicyclic structures that differ from one another not only in functional
groups, but also in their basic carbon skeletons. These lipids can be found in all classes of living things, and are the largest group of natural products. The features of mass spectra of mono-, bi- and tri-cyclic terpenoids: 1-isopropyl-4-methyl-1, 3-cyclohexadiene (I) terpilene; 1-methyl-4-(1-methylethylidene)-1-
cyclohexene (II) terpinolene; 4-methyl-3-(1-methylethylidene)-1-cyclohexene (III); 1,5,5-trimethyl 3-methylene-1-cyclohexene (IV); 2,6,6-trimethylbicyclo\\\\\\\\\\\\\\\\ [3.1.1]-2-heptene (V) �?¯�?�?¡ -pinene; 2,2,6-trimethylbicyclo [3.1.1]-2-heptene (VI) �?¯�?�?¢ -pinene; 2,2-dimethyl-3-methylenebicyclo [2.2.1]-heptane (VII) camphene;1-isopropyl-4-methylbicyclo [3.1.0]-2-hexene (VIII) �?¯�?�?¢ -thugene; 5-isopropyl-2-methylbicyclo [3.1.0]-2-hexene (IX) �?¯�?�?¡ -thugene; 1-methyl-6-(1-methylidene) bicycle [3.1.0] hexane (X); 3,7,7-trimethylbicyclo [4.1.0]-3-heptene (XI) �?¯�?�?¤ -3-carene; 4,7,7-trimethylbicyclo [4.1.0]-2-heptene (XII) (+)-4-carene; 3,7,7- trimethylbicyclo [4.1.0]-2-heptene (XIII) (+)-2-carene; 1,7,7-trimethyltricyclo [2.2.1.0(2.6)]-heptane (XVI) tricyclene; 1,3,3-trimethyltricyclo [2.2.1.0(2.6)]- heptane (XVII) cyclofenchene extracted from natural raw materials and comprising a number of drugs were investigated. The mass spectra for: cyclohexene- 3-(tretbutyl) peroxide (XIV) and 3-isopropyl-1-cyclohexene (XV) were investigated as well. It was established that the mass spectra of these compounds are absolutely identical in mass values of peaks of fragment ions, where their relative intensities have minor differences. In the spectra of all compounds the observed characteristic ions were [M-CH (CH3)2] and [M-CH (CH3)2 –H2]. The latter has a structure with m/z 91 that is attributed to pathing. All fragment ions correspond to even-electron cations. The identity of mass spectra of the studied tepenoids is explained by isomerization of molecular ions, similar to isomerization of terpenes in chemical transformations under the action of acids, also under the influence of other catalysts, temperature and light