Abstract
Comparative molecular similarity index analysis (CoMSIA) was used to establish a three-dimensional quantitative structure-activity relationship (3D-QSAR) model with structural parameters of quinolones as the independent variables and plasma protein binding rate (logf(b)) as the dependent variable to predict the logf(b) values of remaining quinolones in this study. In addition, the mono-substituted and bis-substituted reaction schemes that significantly influenced the plasma protein binding rate of quinolones were determined through an analysis of the 3D-QSAR contour maps. It was found that the replacement of small groups, hydrophobic groups, electronegative groups, or hydrogen bond acceptor groups at the substitution sites significantly reduce the logf(b) values of quinolone derivatives. Furthermore, the mechanism of decrease in binding rate between trovafloxacin (TRO) derivatives and plasma protein was revealed qualitatively and quantitatively based on molecular docking and molecular dynamics simulation. After modification of the target molecule, 11 TRO derivatives with low plasma protein binding rates were screened (reduced by 0.50-24.18%). Compared with the target molecule, the molecular genotoxicity and photodegradability of the TRO derivatives was higher (genotoxicity increased by 4.89-21.36%, and photodegradability increased by 9.04-20.56%), and their bioconcentration was significantly lower (by 36.90-61.41%).