{Reference Type}: Journal Article {Title}: Mutagenicity assessment of two potential impurities in preparations of 5-amino-2,4,6 triiodoisophthalic acid, a key intermediate in the synthesis of the iodinated contrast agent iopamidol. {Author}: Rossi S;Bussi S;Bonafè R;Incardona C;Vurro E;Visigalli M;Buonsanti F;Fretta R; {Journal}: Mutat Res Genet Toxicol Environ Mutagen {Volume}: 893 {Issue}: 0 {Year}: 2024 Jan {Factor}: 3.189 {DOI}: 10.1016/j.mrgentox.2023.503720 {Abstract}: 5-Aminoisophthalic acid and 5-nitroisophthalic acid (5-NIPA) are potential impurities in preparations of 5-amino-2,4,6-triiodoisophthalic acid, which is a key intermediate in the synthesis of the iodinated contrast agent iopamidol. We have studied their mutagenicity in silico (quantitative structure-activity relationships, QSAR) and by the bacterial reverse mutation assay (Ames test). First, the compounds were screened with the tools Derek Nexus™ and Leadscope®. Both compounds were flagged as potentially mutagenic (class 3 under ICH M7). However, contrary to the in silico prediction, neither chemical was mutagenic in the Ames test (plate incorporation method) with or without S9 metabolic activation.