Question

What functional group(s) does the 4,5-oxide have? Also, explain why the 4,5-oxide is harmful.

Answer 1

The functional groups are: Aromatic (from arenes family) and Eter.

In the metabolism of polycyclic hydrocarbons, a variety of arene oxides are formed as the initial products of the oxidation of the aromatic double bonds, a process catalyzed by the microsomal mixed-function oxidase system, and these arene oxides are converted into hydroxylated derivatives that are major metabolites of the hydrocarbons. In addition to arene oxides undergoing nonenzymatic isomerization to phenols, conversion to dihydrodiols by microsomal epoxide hydrase, and conjugation with glutathione, arene oxides also react readily with a variety of nucleophiles, including DNA, RNA, and protein. Although arene oxides have been suggested to be the carcinogenic metabolites of polycyclic hydrocarbons, no systematic studies on the carcinogenicity of the several possible arene oxides of a single hydrocarbon have been reported.

Until recently, most arene oxides of polycyclic hydrocarbons that have been synthesized and evaluated for mutagenicity and carcinogenicity were the K-region arene oxides. These K-region arene oxides have been shown to be more active than the parent hydrocarbons in producing malignant transformations and mutations of mammalian and bacterial cells in culture. In contrast to results with cellculture systems, several studies in vivo on the carcinogenicity of K-region arene oxides have shown that these derivatives are considerably less carcinogenic than the corresponding parent hydrocarbons.