Z anthracene

Sources. Dibenz[ ,/ ]anthracene (DBA) is a major component of polynuclear aromatic hydrocarbons, also known as polycyclic aromatic hydrocarbons, and is usually bound to small particulate matter present in urban air, industrial and natural combustion emissions, and cigarette smoke. 

Toxicology. DBA produced carcinomas in animals after oral or dermal exposure and injection site tumors after subcutaneous or intramuscular administration. 

Mammary carcinomas and forestomach papillomas were observed in mice after gavage administration. DBA has also been shown to cause skin papillomas and carcinomas in mice when applied dermally 3 times/week for a lifetime.Subcutaneous injection of Ipmol of DBA three times weekly for 20 doses induced injection site sarcomas in 100% of female Sprague-Dawley rats by 33 weeks.  

Most human exposure to DBA in the environment or workplace occurs when it is particle bound and a component of complex mixtures of polycyclic aromatic hydrocarbons. Thus it has not been possible to study the effects of human exposure to DBA alone. 

The lARC considers that there is sufficient evidence that DBA is carcinogenic in experimental animals and that it is probably carcinogenic to humans.  

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Fig. 5a-c. A typical distribution of polycyclic aromatic hydrocarbons in a atmospheric fallout sample, Alexandria City - Egypt b bottom incineration ash leachate of municipal solid waste - USA c hydrothermal petroleum, Escanaba Trough, NE Pacific Ocean. PAH Compound identifications N = naphthalene, MN = methylnaphthalene, DMN = dimethylnaphthalenes, P = phenanthrene, MP = methylphenanthrene, Fl = fluoranthene, Py = pyrene, BaAN = benzol anthracene, DH-Py = dihydropyrene, 2,3-BF = 2,3-benzofluorene, BFL = benzo[fc,/c]fluoranthene, BeP = benzo[e]pyrene, BaP = benzo[a]pyrene, Per = perylene, Cx-228 = methyl-228 series, Indeno = indeno[ l,2,3-c,d]pyrene, DBAN = dibenz[a,/z]anthracene, BPer = benzo[g,/z,z] perylene, AAN = anthanthrene, DBTH = dibenzothiophene, Cor = coronene, DBP = dibenzo [a,e]pyrene, DBPer = dibenzo [g,h,i] perylene... 

Synonyms BA benzanthracene 1,2-benz(anthracene benzo([Pg.68]

Toxicology. Benz[[Pg.69]

The stereospecificity of methanol addition to neopentylsilenes has been investigated by Jones and Bates68. The mild thermal retro-Diels-Alder reaction (at ca 200 °C) of E and Z anthracene [4 + 2] cycloadducts 110 liberates stereospecifically the corresponding silenes 111, which are trapped by methanol. The ratio of the diastereomeric products 396a/396b coincides with the E/Z ratio of the precursors 110 (equation 117). In photochemical reactions of similar silene precursors, alcohols were used also to probe the decomposition mechanism69. 

The second equilibrium ion-pair acidity constant (pK2) of 9,10-dihydrodibcnz[a,/z]-anthracene (DBDHA) (2) in THF at 298 K has been found to be considerably lower than for other 9,10-dihydroanthracene (DHA) derivatives and the dependence on the counter ions sodium (pK% 28.5) and potassium (pK2 30.4) is less marked as a consequence of extended >, 71-conjugation of the dianion (3) with the outer benzene rings.5 The disodium, dipotassium, and dirubidium salts exist as contact ion triplets and the dilithium salt as a solvent-separated triplet. 

Fig. 2.20. Composition (mean%) of 16 individual polycyclic aromatic hydrocarbons (PAHs) to total PAHs detected in various environmental media in (a) air (n = 24), (b) soil (n = 226), (c) freshwater (n = 46), and (d) marine sediment (n = 159), from the South Korea. Naphthalene NAP, Acenaphthylene ACY, Acenaphthene ACE, Fluorine FLU, Phenanthrene PHE, Anthracene ANT, Fluoranthene FLT, Pyrene PYR, Benz[a]ant-hracene BaA, Chrysene CHR, Benzo[6]fluoranthene BbF, Benzo[ ]fluoranthene BkF, Benzo[a]pyrene BaP, Indeno[l,2,3,c,d]pyrene I123cdP, Dibenz[a,/z]anthracene DahA, Ben-zo[g,/y ]perylene BghiP.

Pyka separated 16 PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo [a] anthracene, chrysene, benzo[/>]fluoranthene, benzo[fe]fluoranthene, benzo[a]py-rene, dibenzo[a,/z]anthracene, benzo[g,/i,i]perylene, and indeno[l,2,3-C(i]pyrene) according to the Environmental Protection Agency (EPA) by gradient HPLC on a LiChrospher PAH column using acetonitrile and water as mobile phases. Retention times fr (sec) of investigated PAHs were correlated with topological indices based on the adjacency matrix (M, 012) and the... 

B[a]A = benz[ z]anthracene, % TBA = % tumor-bearing animals 2-Methylphenol, 3-methylphenol, 4-methylphenol = o-, m-, and/ -cresol, respectively Painting dose = 50 mg of cigarette smoke condensate/day Painting dose = 25 mg of cigarette smoke condensate/day... 

Ofl-Dihydro-8,1 Oo-dihydroxy-3,11 -dimethyl-1 //-cyclopent[Z>]anthracene-5,10-dione, see K-30024... 

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