【摘要】 本文以三种简化的模型分子模拟多环芳烃湾区代谢历程最终致癌物二醇环氧化物的三种空间异构体（反式平伏键型,顺式直立键型,顺式平伏键型）,用量子化学从头计算（STO-3G）和分子静电势方法研完了多环芳烃最终致癌物致癌活性与其空间构型的关系.从计算所得的E_LUMO值、环氧与碳原子间重迭集居数、偶极矩以及分子静电势图的特征分析,表明无论顺式或反式构型,其二醇羟基取平伏健均比取直立键构型有利于与生物大分子负电中心的反应,故其致癌活性应较强.这些都与实验事实相符,从而支持了化学致癌的亲电反应机理和D.M.Jerina的湾区理论。更多还原

【Abstract】 Three simplified model molecules, trans （eg, eg’）, cis （ax, ax’） and cis （eg, eq’ ） were selected to simulate the three stereoisomers of the diol-epoxide, the ultimate carcinogen in the "bay-region" metabolite of polycyclic aromatic hydrocarbon （PAH）, and attempts were made to apply ab initio calculation （STO-3G） and molecular electrostatic potential method to investigate the relationship between the carcinogenic activity and the stereo conformation. An analysis of the data such as E_LUMO, the overlap population of epoxide oxygen and carbon atoms, dipole moment and characteristics of the molecular electrostatic potential maps show that the quasidiequatorial conformation of the hydroxyl groups of the diol was more satisfactory than the quasidiaxial one for the reaction with an electrophile in biological macromolecules, so the （eg, eq’） isomer would be more potent in carcinogenicity than the （ax, ax’） isomer, no matter whether it is cis or trans. The results are in agreement with those of recent biological experiments, thus supporting the mechanism of reactive electrophiles for chemical carcinogenesis of PAH and the "bay-region" theory.更多还原