Carcinogenic hydrocarbons, complexes

In order to explain an antagonism phenomenon which they had observed Lacassagne, Buu-Hoi, Daudel, and Rudali42 imagined that carcinogenic hydrocarbons must be capable of forming an addition complex with the substrate which determines cellular division and that this addition is only effective for the production of carcinomas if it takes place at certain definite points in the cell. 

Another way in which Pt could bind to DNA is through the formation of intercalation compounds. The parallel here is with the hydrocarbon carcinogens and the nucleic acid stains, the acridines. It has been shown that metal chelates will form this same type of jt-complex. For example, palladium oxinate will form exactly the same type of -complexes as anthracene (88). 

The NO + 03 chemiluminescent reaction [Reactions (1-3)] is utilized in two commercially available GC detectors, the TEA detector, manufactured by Thermal Electric Corporation (Saddle Brook, NJ), and two nitrogen-selective detectors, manufactured by Thermal Electric Corporation and Antek Instruments, respectively. The TEA detector provides a highly sensitive and selective means of analyzing samples for A-nitrosamines, many of which are known carcinogens. These compounds can be found in such diverse matrices as foods, cosmetics, tobacco products, and environmental samples of soil and water. The TEA detector can also be used to quantify nitroaromatics. This class of compounds includes many explosives and various reactive intermediates used in the chemical industry [121]. Several nitroaromatics are known carcinogens, and are found as environmental contaminants. They have been repeatedly identified in organic aerosol particles, formed from the reaction of polycyclic aromatic hydrocarbons with atmospheric nitric acid at the particle surface [122-124], The TEA detector is extremely selective, which aids analyses in complex matrices, but also severely limits the number of potential applications for the detector [125-127],... 

The presence in mineral oil of potential carcinogens also raised safety concerns relating to FCA/FIA. Mineral oil is composed of a complex mixture of both cyclic and non-cyclic hydrocarbons of varying chain length, some of which display carcinogenic potential. Arlacel A was also found to be capable of inducing cancer in mice. 

It is clear that the effects of induction or inhibition of the metabolism will be complex because of the large number of possible metabolic pathways through which benzofalpyrene may be metabolized. For instance, the microsomal enzyme inducer 5,6-benzoflavone inhibits the carcinogenicity of benzofalpyrene in mouse lung and skin, whereas inhibitors such as SKF 525A may increase the tumor production from certain polycyclic hydrocarbons. 

At low enough temperatures vibrational fine structure of aromatic chromophores may be well resolved, especially if they are embedded in a suitable matrix such as argon or N2, which is deposited on a transparent surface at 15 K. This matrix isolation spectroscopy77166 may reveal differences in spectra of conformers or, as in Fig. 23-16, of tautomers. In the latter example the IR spectra of the well-known amino-oxo and amino-hydroxy tautomers of cytosine can both be seen in the matrix isolation IR spectrum. Figure 23-16 is an IR spectrum, but at low temperatures electronic absorption spectra may display sharp vibrational structure. For example, aromatic hydrocarbons dissolved in n-heptane or n-octane and frozen often have absorption spectra, and therefore fluorescence excitation spectra, which often consist of very narrow lines. A laser can be tuned to excite only one line in the absorption spectrum. For example, in the spectrum of the carcinogen ll-methylbenz(a)anthrene in frozen octane three major transitions arise because there are three different environments for the molecule. Excitation of these lines separately yields distinctly different emission spectra.77 Likewise, in complex mixtures of different hydrocarbons emission can be excited from each one at will and can be used for estimation of amounts. Other related methods of energy-... 

HMPT is now thought to be a potent carcinogen. It should be handled with extreme care inhalation of the vapour and contact with the skin should be avoided. This solvent is miscible both with water and with many polar and non-polar organic solvents with the exception of saturated aliphatic hydrocarbons. It forms a complex with chlorinated solvents by which means it may be removed from aqueous solutions. The solvent may be dried by shaking with calcium hydride or barium oxide followed by distillation under reduced pressure and... 

PNA (polynuclear aromatic) any of numerous complex hydrocarbon compounds consisting of three or more benzene rings in a compact molecular arrangement. Some types of PNA s are known to be carcinogenic (cancer causing). 

Aryl hydrocarbon hydroxylase (AHH) is a complex mixed function oxidase enzyme which converts polycyclic aromatic hydrocarbons such as DMBA to more hydrophilic and readily excretable products. During this process metabolites that are more carcinogenic than the parent compound can be produced. The distribution of MFO enzymes, their activity, and the balance between conversion of procarcinogens to active carcinogens and their detoxification is probably a... 

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