Methyl Effect on the Metabolism, Chemical Stability, and Permeability Profile of Bioactive N-Sulfonylhydrazones

Sulfonylhydrazones are privileged structures with multifaceted pharmacological activity. Exploring the hypoglycemic properties of these organic compounds, we previously revealed a new series of N-sulfonylhydrazones (NSH) as antidiabetic drug candidates. Here, we evaluated the microsomal metabolism, chemical stability, and permeability profile of these NSH prototypes, focusing on the pharmacokinetic differences in N-methylated and non-N-methylated analogs. Our results demonstrated that the N-methylated analogs (LASSBio-1772 and LASSBio-1774) were metabolized by CYP, forming three and one metabolites, respectively. These prototypes exhibited chemical stability at pH 2.0 and 7.4 and brain penetration ability. On the other hand, non-N-methylated analogs (LASSBio-1771 and LASSBio-1773) were hydrolyzed in acid pH and could not cross the artificial blood-brain barrier. The cyano group in LASSBio-1771 was postulated as a possible site of interaction with the heme group, potentially inhibiting CYP enzymes. Moreover, prototypes with the methyl ester group were metabolized by carboxylesterase, and non-N-methylated analogs did not show oxidative metabolism. The prototypes (except LASSBio-1774) showed excellent gastrointestinal absorption. Altogether, our data support the idea that the methyl effect on NSH strongly alters their pharmacokinetic profile, enhances the recognition by CYP enzymes, promotes brain penetration, and plays a protective effect upon acid hydrolysis.