RESUMO
According to the results of quantitative pattern recognition for 153 N-nitroso compounds (NNCs) based on Di-region theory, it is put forward that the esters formed from the metabolism of NNCs on ..- or ..-position could be alkylating agents of DNA bases with the anchimeric assistance of the N-nitroso group. This viewpoint, combined with the conception of ..-metabolism activation, can explain the structurecarcinogenic activity relationship reasonably. Quantum chemistry ab initio calculations are carried out to study the activity of different metabolites of NNCs in direct alkylation and the anchimeric assistant processes. By ONIOM method, a QM/MM calculation is carried out to study the crosslink of DNA base pair by methylalkylnitrosamines. Based on the computational results, the quantitative structure and carcinogenic activity relationship of 58 N-nitrosoureas that have got animal carcinogenicity tests reported are studied.
