7,12-Dimethylbenz

A stmcturally related series of phenyfiiydrazones resulted ia the selection of compound A-007 [2675-35-6] (DEKK-TEC)(37) for the treatment of hormone-dependent tumors. A-007 is an antiestrogen that, ia contrast to tamoxifen, demonstrated inhibitory activity both ia the presence and absence of estradiol ia ZR-75-1 estrogen-dependent human breast cancer cells, and afforded more protection than tamoxifen ia the 7,12-dimethylbenz[i7]anthracene... 

Dimethylbenz[from acetone/EtOH. 

Diethyl aniline, 54 Diethylcarbaniazine citrate, 54 Diethyl carbamyl chloride, 54 Diethyl chlorophosphate, 54 Diethylene triamine, 54 Diethyl ether, 54 Di(2-ethylhexyl) phthalate, 54 Diethyl ketone, 54 Diethyl-p-phenylenediamine, 54 Diethyl phthalate, 54 Diethylstilbestrol, 55 Diethyl sulfate, 55 Diethyl zinc, 55 Difluoromethane chloride, 55 Digitoxin, 55 Diglycidyl ether, 55 Digoxin, 55 Diisobutyl ketone, 55 Diisopropylamine, 55 Diisopropyl ether, 55 DIKAMIN , 2,4-D, 55 DIKONIRT , 2,4-D, 55 Dimefox, 55 Dimethoate, 55 3,3 -Dimethoxybenzidine, 55 n,n-Dimethylacetamide, 56 Dimethylamine, 56 4-Dimethylaminoazobenzene, 56 Dimethylaminoethanol, 56 n,n-Dimethyl aniline, 56 7,12-Dimethylbenz[a]anthracene, 56 3,3 -Dimethylbenzidine, 56... 

Two types of reactions are important in the photochemical transformation of PAHs, those with molecnlar oxygen and those involving cyclization. lllnstrative examples are provided by the photooxidation of 7,12-dimethylbenz[a]anthracene (Lee and Harvey 1986) (Fignre 1.14a) and benzo[a]pyrene (Lee-Ruff et al. 1986) (Figure 1.14b), and the cyclization of CM-stilbene (Figure 1.14c). 

McMillan DC, PP Fu, CE Cerniglia (1987) Stereoselective fungal metabolism of 7,12-dimethylbenz[a]anthra cene identification and enantiomeric resolution of a K-region dihydrodiol. Appl Environ Microbiol 53 2560-2566. 

Bhuvaneswari, V., B. Velmurugan, S. Balasenthil, C. R. Ramachandran, and S. Nagini. 2001. Chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a] anthracene-induced hamster buccal pouch carcinogenesis. Fitoterapia 72(8) 865-874. 

Research in PAH carcinogenesis has made major advances in the past decade. Most notable has been identification of diol epoxide metabolites as the active forms of benzo[a]pyrene, 7,12-dimethylbenz[tf]anthracene, and other carcinogenic PAH. This finding has stimulated enormous research activity and opened the way to determination of the detailed molecular mechanism of action of this important class of carcinogenic molecules. 

For example, 7,12-dimethylbenz[a]anthracene is a particularly potent carcinogen for the mammary gland of young female Sprague-Dawley rats after oral or intravenous administration (25,26), dietary benzo[a]pyrene leads to leukemia, lung adenoma and stomach tumors in mice (27), and either of these hydrocarbons can induce hepatomas in male mice when injected on the first day of life (28). Nevertheless, the mouse skin system has proved to be particularly valuable because of the rapidity of tumor induction, the ease of detection of tumors and because the multi-stage nature of the carcinogenic process was experimentally established in this system. 

Similarly, the potent activity of 7,12-dimethylbenz[aj-anthracene can be destroyed by the presence of methyl groups on the 2-or 3- positions but the 4-methyl derivative remains active. 

Methods for the synthesis of the biologically active dihydrodiol and diol epoxide metabolites of both carcinogenic and noncarcinogenic polycyclic aromatic hydrocarbons are reviewed. Four general synthetic routes to the trans-dihydrodiol precursors of the bay region anti and syn diol epoxide derivatives have been developed. Syntheses of the oxidized metabolites of the following hydrocarbons via these methods are described benzo(a)pyrene, benz(a)anthracene, benzo-(e)pyrene, dibenz(a,h)anthracene, triphenylene, phen-anthrene, anthracene, chrysene, benzo(c)phenanthrene, dibenzo(a,i)pyrene, dibenzo(a,h)pyrene, 7-methyl-benz(a)anthracene, 7,12-dimethylbenz(a)anthracene, 3-methylcholanthrene, 5-methylchrysene, fluoranthene, benzo(b)fluoranthene, benzo(j)fluoranthene, benzo(k)-fluoranthene, and dibenzo(a,e)fluoranthene. 

Although benz(a)anthracene (BA) is generally considered noncarcino-genic (27), it is a weak tumor initiator when administered with a phorbol ester promoter (28). More importantly, BA is a convenient model for the highly potent carcinogenic PAH 7,12-dimethylbenz(a)-anthracene and 3-methylcholanthrene (27), both of which are BA derivatives but which offer more serious synthetic problems. 

Human exposure to complex mixtures of polycyclic aromatic hydrocarbons (PAH) occurs through inhalation of tobacco smoke and polluted indoor or outdoor air, through ingestion of certain foods and polluted water, and by dermal contact with soots, tars, and oils CO. Methylated PAH are always components of these mixtures and in some cases, as in tobacco smoke and in emissions from certain fuel processes, their concentrations can be in the same range as some unsubstituted PAH. The estimated emission of methylated PAH from mobile sources in the U.S. in 1979 was approximately 1700 metric tons (2). The occurrence of methylated and unsubstituted PAH has been recently reviewed (1, 2). In addition to their environmental occurrence, methylated PAH are among the most important model compounds in experimental carcinogenesis. 7,12-Dimethylbenz[a]anthracene, one of... 

The Intercalation of Benzo[a]pyrene and 7,12-Dimethylbenz[a]anthracene Metabolites and Metabolite Model Compounds into DNA... 

Figure 2. Reactive metabolites and metabolite model compounds derived from 7,12-dimethylbenz[a]anthracene.

This list includes BP, 7,12-dimethylbenz[a]anthracene, 3-methylchol-anthrene, dibenzo[a,i]pyrene and dibenzo[a,h]pyrene. These PAH can be activated both by one-electron oxidation and/or monooxygenation. There are a few PAH with low IP which are inactive (Table I), such as perylene, or weakly active, such as anthanthrene. This indicates that low IP is a necessary, but not sufficient factor for determining carcinogenic activity by one-electron oxidation. These inactive or weakly active PAH have the highest density of positive charge delocalized over several aromatic carbon atoms in their radical cations, whereas the active PAH with low IP have charge mainly localized on one or a few carbon atoms in their radical cations. 

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