Fragrance allergens: Classification and ranking by QSAR

Quantitative structure-activity relationship (QSAR) models which predict both skin penetration and cell mediated immunity for small molecular weight non-electrolytes developed earlier were validated on 74 known allergens and non-allergens chosen among fragrance chemicals in common use to test discriminating and grading power. While the test set used for classification was based on experience in humans exclusively, the rank model was tested for sensitization potency including guinea pig data also. In the classification test, 12 of 74 compounds fell in the indeterminate range and were non-classifiable by the present QSAR model. On the remaining 62 compounds the model performs with 90% sensitivity and 100% specificity at 92% concordance. The rank model correctly grades 65 of 74 compounds (88% concordance), with 60% specificity based on exact prediction of non-allergens (NON), and 95% sensitivity on allergens (ACD) allowing for a variance of +/- one level among weak, moderate and severe ratings. In combination, the two models perform with 93% overall concordance on the test set of 74 compounds.