研究论文

  • 张大仁.(艹屈)和5-甲基(艹屈)的ab initio计算[J].环境科学学报,1988,8(3):346-351

  • (艹屈)和5-甲基(艹屈)的ab initio计算
  • AB INITIO COMPUTATIONS OF CHRYSENE AND 5-METHYLCHRYSENE
  • 基金项目:国家自然科学基金资助课题
  • 作者
  • 单位
  • 张大仁
  • 中国科学院生态环境研究中心 北京
  • 摘要:湾区非角环上的甲基取代能大大增加多环芳烃的致癌性,量子化学的从头计算(ab-initio)指出,5-甲基(艹屈)C1-C2键的电子性质有利于在此健发生亲电反应,电子密度分布图说明5-甲基(艹屈)在C1—C2键周围的电子密度明显大于(艹屈)相应部分的电子密度,这也有利于亲电试剂的进攻,因而在代谢过程中,5-甲基(艹屈)容易在此位置发生亲电氧化形成环氧化物,进而形成终致癌剂,这就使5-甲基(艹屈)的致癌性比(艹屈)大大增强。
  • Abstract:The substitution of a methyl group on a nonbenzo bay-region site of a polycyclic aromatic hydrocarbon can greatly enhance its carcinogenic activity. Ab initio computations of chrysene and 5-methylchrysene show that the electron properties of C1-C2 bond of 5-methylchrysene are favorable for an electrophilic reaction. Electron density maps indicate that electron density around C1-C2 bond of 5-methylchrysene is is higher than that of the similar part of chrysene, which also shows that the C1-C2 boud of 5-methylchrysene attacked by electrophilic agent more easily. Therefore, 5-methylchrysene is easily oxidized to form an epoxide in C1-C2 bond and to form an ultimate carcinogen during metabolism.These effects result in much higher carcinogenicity of 5-methylchrysene than that of chrysene.

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