5-Methyl benz anthracene

In a recent comprehensive study with respect to the substituent effects of benz anthracene carbocations,280 exclusive protonation at C(7) (102) and C(12) (103, bay region protonation) in the C ring was shown to occur. The relative stability of the resulting carbocations, however, strongly depends on the substitution pattern. Substrates methyl-substituted in the A ring give mixtures of the two cations. Protonation of 5-, 6-, and 7-methyl- and 7-ethyl-substituted compounds, in turn, yields... 

Human recombinant AKRs have been shown to catalyze identical reactions for bay region trans-dihydrodiols (phenanthrene, chrysene, B[a]P, benz[a]anthracene), methylated bay region trarcs-dihydrodiols (5-methylchrysene and 7,12-DMBA), and fjord region trans-dihydrodiols (B[g]C) [18-20], Thus far, no human AKR has been show to be an efficient catalyst of the oxidation of the potent proximate carcinogen HR,12R-dihydroxy-dihydro-DB[a,l]P. Interestingly, this metabolic pathway of... 

Benz[a]anthracene, ethyl-Benz[a]anthracene, ethylmethyl-Benz[a]anthracene, methyl-Benz[a]anthracene, 1-methyl-Benz[a]anthracene, 2-methyl-Benz[a]anthracene, 3-methyl-Benz[a]anthracene, 4-methyl-Benz[a]anthracene, 5-methyl-Benz[a]anthracene, 6-methyl-Benz[a]anthracene, 8-methyl-Benz[a]anthracene, 9-methyl-Benz[a]anthracene, 10-methyl-Benz[a]anthracene, 12-methyl-Benz[a]anthracene, methylene-Benz[a]anthracene, propyl-Benz[a]anthracene, tetramethyl-Benz[a]anthracene, trimethyl-7H-Benz[de]anthracene... 

Table I. Effect of a Methyl Group at a Single Starred Position on Carcinogenic Activity of Benz[a]anthracene Derivatives...

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. 

Whereas peri methyl substitution does not block dihydrodiol formation in the adjacent ring in the benz[a]anthracene system (38,39), it apparently does so in the chrysene system. 7,8-Dihydro-... 

The carcinogenicity of PAH with relativelyTigh IP, such as benzo[c]phenanthrene, benz[a]anthracene, chrysene, 5-methyl chrysene and dibenz[a,h]anthracene (Table I), can be related to the formation of bay-region diol epoxides catalyzed by monooxygenase enzymes (j>). However, the most potent carcinogenic PAH have IP < ca. 7.35 eV. 

In the case of benz[a]anthracene the positions 7 and 12 are approximately equivalent. Mackor and collaborators therefore discussed the effect of the position of methyl groups on the spectrum of the proton addition complex benz[a]anthracene in connection with the investigation of the basicity of methyl-benz[a]anthracenes (Mackor et al., 1956). The carbonium ions A and B are present in solution ... 

The piTj5-values of the methyl derivatives of benz[a]anthracene, summarized in Table 23, are particularly interesting. In the case of the unsubstituted compound, two positions of approximately equal proton affinity have to be taken into account. Thus two isomeric proton addition complexes A and B are present in solution (cf. IID, page 229). 

A and B. This calculation is, of course, not very precise but it does correctly reflect the effect of methyl substitution on the basicity. Table 23 summarizes the values obtained in this way for all monomethyl derivatives and for the 7,12-dimethyl derivative of benz[a]anthracene (Mackor et al., 1956 Dallinga et al., 1958b). gives the figure of the total basicity, pA"(A) the value for ion A, pif(B) the value for ion B, and... 

Similar results were obtained by Mackor et al. (1956) in the theoretical treatment of the effect of the methyl group position in isomeric methyl benz[a]anthracenes. The theoretical calculations therefore suggest that the greater importance is to be attributed to the inductive effect. 

Benzaldehyde, 4-ethoxy-3-methoxy-, 56, 44 Benzaldehyde, 4-ethoxy-3-methoxy-, ethylene acetal, 56, 44 Benzaldehyde, 4-isopropyl-, 55,10 Benz[e ] anthracene, 58, 15, 16 BENZENAMINE, 4-bromo-Ar, V-dimcthyl-3-(tnfluoromethyl)-, 55, 20 Benzene, bromo-, 55,51 Benzene, 1 bromo-4-chloro-,55, 51 Benzene, 4-bromo-l, 2-dimethyl, 55, 51 Benzene, l-bromo-4-fluoro-, 55, 51 Benzene, 1 -bromo-4-methoxy-, 55,51 Benzene, l-bromo-3-methyl-, 55, 51 Benzene, 4-(cr/-buty 1-1-ethyl, 55, 10 Benzene, chemical hazard warning, 58, 168 Benzene, chloro-,56, 86 Benzene, l-ethyl-4-isopropyl-, 55, 10... 

Substances that are isosteric equivalents of substances that are toxic or pharmacologically active may also possess these biological properties. It is also possible that biological properties may be bestowed, exacerbated, or attenuated when isosteric modifications are made. This point is illustrated by the following examples. 7-Methyl-benz[a]anthracene (36) is a known carcinogen, whereas 7-methyl-l-fluorobenz[o]... 

The regiochemistry of deuteration of polycyclic carbonyl compounds such as methyl derivatives of benz[de]anthracen-6- and -7-one is subject to orbital control.147 Charge alternation and deuterium isotope effects in these and related compounds were studied by NMR and MNDO methods. 

Analytical Properties Resolution of several enantiomers of polycyclic aromatic hydrocarbons, for example, chrysene 5,6-epoxide, dibenz[a,h]anthracene 5,6-epoxide, 7-methyl benz[a]anthracene 5,6-epoxide resolution of barbiturates, mephenytoin, benzodiazepinones, and succinimides direct separation of some mono-ol and diol enantiomers of phenanthrene, benz[a]anthrene, and chrysene ionically bonded to silica gel, this phase provides resolution of enantiomers of c/s-dihydroidiols of unsubstituted and methyl- and bromo-substituted benz[a]anthracene derivatives having hydroxyl groups that adopt quasiequatorial-quasiaxial and quasiaxial-quasiequatorial conformation Reference 31-35... 

Analytical Properties Ionically bonded to silica, this phase provides good resolution of enantiomeric quasiequatorial frans-dehydriols of unsubstituted and methyl- and bromo-substituted benz[a]anthracene derivatives covalently bonded to silica, this phase provides good resolution of enantiomeric pairs of quasidiaxial frans-dihydrodiols of unsubstituted and methyl- and bromo-substituted benz[a]anthracene derivatives by addition of a third solvent (chloroform) to the classical binary mixture (hexane-alcohol) of the mobile phase, resolution of enantiomers of tertiary phosphine oxides is possible Reference 31-33, 36, 37... 

Polyaromatic hydrocarbons (naphthalene, fluorene, phen-anthrene, pyrene, benz[a]anthracene Linear polymer coated capillary [poly(N-tert.-butyl acrylamide-co-2-acrylamido-2-methyl-1 -propanesulfonic acid] Acetonitrile-50 mA/Tris buffer, pH 7.3 (30 70) 600 mm x 25 pm i.d. 450 mm effective column length 11... 

Several PAHs and hydroxylated or methylated PAH derivatives induce oestrogenic or dioxin-like (antioestrogenic) effects in fish and mammalian cell lines (Santodonato, 1997 Villeneuve et al., 2002 Michallet-Ferrier et al., 2004). For instance, benz[u]anthracene and dibenz[u/2]anthracene elicit oestrogenic responses in vitro (Villeneuve et al., 2002). These two PAHs and five others may also elicit dioxin-like responses, as shown by their induction of ethoxyresorufm-D-deethylase (EROD) activity, a biomarker for cytochrome P450 lAl (Gravato Santos, 2002 Villeneuve et al., 2002). 

The polycyclic aromatic hydrocarbons (PAHs) encompass a further group of environmental chemicals with antiestrogenic activity. Examples are benzo[a] pyrene, benz[a]anthracene, 3-methyl-cholanthrene, and 7,12-dimethylbenz[a] anthracene [120b]. 

CHLOROMETHYLMERCURY see MDD750 7-CHLOROMETHYL-12-METHYL BENZ(a)ANTHRACENE see CIN750 CHLOROMETHYL METHYL ETHER see CIO250... 

C19H140 benz(a)anthracene-7-methanol 16110-13-7 692.65 62.670 2 31600 C19H28N06 2,12-dihydroxy-4-methyl-11,16-dioxoseneciona 2318-18-5 527.15 46.499 1,2... 

Figure 2 Structures of polycyclic aromatic hydrocarbons. Symbols used in this figure and text Na (naphthalene). Ay (acetonaphthylene), Ae (acenaphthene), FI (fluorene). Pa (phenanthrene), A (anthracene), MPa (methyl phenanthrene), F (fluoranthene), Py (pyrene), BaA (benz(a)anthracene), Chy (chrysene), BlcF (benzo(k)fluoranthene), BbF (benzo(b)fluoranthene), BaP (benzo(a)pyrene), IP (indenopyrene), B(ghi)Pe (benzo(ghi)perylene), and Db(ah)A...

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