[Quantitative structure-activity relationship prediction of carcinogenicity of N-nitroso compounds based on category...

Objective: New quantitative structure-activity relationship (QSAR) method was used to predict N-nitroso compounds (NOCs) carcinogenicity. This could provide evidences for health risk assessment of the chemicals. Methods: Total 74 chemical substances of NOCs were included as target chemicals for this validation study by using QSAR Toolbox based on category approach and read-across. The included 74 NOCs were categorized and subcategorized respectively using "Organic functional groups, Norbert Haider " profiler and "DNA binding by OASIS V.1.1" profiler. Carcinogenicity of rat were used as target of prediction, the carcinogenicity results: of analogues in chemical categories were cross-read to obtain the carcinogenic predictive results of the target chemicals. Results 74 NOCs included 26 nonclic N-nitrosamines, 24 cyclic N-nitrosamines and 24 N-nitrosamides The sensitivity, specificity and concordance of the category approach and read-across for predicting carcinogenicity of 74 NOCs were 75% (48/64), 70%(7/10) and 74% (55/74) respectively. The concordance for noncyclic N-nitrosamines, cyclic N-nitrosamines and N-nitrosamides were 88% (23/26), 71% (17/24) and 63% (15/24) respectively. Conclusion: QSAR based on category approach and read-across is good for prediction of NOCs carcinogenicity, and can be used for high-throughput qualitative prediction of NOCs carcinogenicity.