Molecular orbital study on the metabolic pathway through the diol epoxide form of carcinogenic benzene in comparison with benzo[a]pyrene.
The stabilization energy for the hydronium-ion-catalyzed hydrolysis of benzene diol epoxide (BDE) in the configuration of anti- or syn-form has been estimated by using the semi-empirical molecular orbital calculations with the CNDO/2 method. The values for the formation of carbonium ion from BDE are compared with those from benzo[a]pyrene, and it is suggested that the anti-form BDE belongs to a relatively strong reactive group with benzo[a]pyrene and benz[a]anthracene. The reactivity of BDE to the cation is completely different from that of polycyclic aromatic hydrocarbon diol epoxides (PAHDEs) from the viewpoint of the electronic structure; the cation from the anti-form BDE has a three center-four electron bond, whereas cations from PAHDEs do not have such a bond and the aromaticity still remains.
Imamura
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A
Department of Chemistry, Faculty of Science, Hiroshima University, Japan.
Tani
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S
Kanda
K
K
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism*; D004101:Dihydroxydihydrobenzopyrenes / Q000378:metabolism*; D004852:Epoxy Compounds / Q000378:metabolism*; D004988:Ethers, Cyclic / Q000378:metabolism*; D006868:Hydrolysis; D008956:Models, Chemical; D008968:Molecular Conformation
D002273:Carcinogens; D002396:Catechols; D004101:Dihydroxydihydrobenzopyrenes; D004852:Epoxy Compounds; D004988:Ethers, Cyclic; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; C061429:3,4-epoxy-1,2,3,4-tetrahydrobenzene-1,2-diol