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采用MNDO方法计算了对称二烷基亚硝胺β-,γ-和δ-位硫酸酯经SN2反应机制与DNA碱基腺嘌呤(A)发生烷化反应的速率控制步骤的势能曲线和活化能,以及β-位硫酸酯经邻基参与作用与腺嘌呤烷化反应过程的势能变化.结果表明,邻基参与作用有利地促进了烷基亚硝胺与DNA的烷化反应,提高了β-位硫酸酯烷化DNA的能力,以此可以解释β-位硫酸酯化的二烷基-N-亚硝基化合物的致癌活性大于γ-和δ-位硫酸酯化的二烷基-N-亚硝基化合物的致癌活性.使得β-位有可能成为亚硝胺的第二亲电活性区.
Using MNDO method, the potential energy curves and activation energies of the rate-controlling steps of symmetrical dialkylnitrosamine β-, γ- and δ-position sulfates via alkylation reaction of SN2 reaction with DNA-based adenine (A) , And the change of potential energy of β-position sulfate through the interaction of adjacent groups with adenine alkylation.The results showed that the participation of adjacent groups favorably promoted the alkylation of alkylnitrosamines with DNA, Bit sulfuric acid ester to alkylate DNA, thereby explaining that the oncogenic activity of β-site sulfated dialkyl-N-nitroso compounds is greater than that of γ- and δ-position sulfated dialkyl-N- The carcinogenic activity of nitroso compounds makes it possible for the beta-site to become the second electrophilic active region of nitrosamines.