Nitro-Substituted Pyridinimine Complexes of Pd(II): Synthesis and Inhibition of MAO-B ex vivo

Abstract

The first ever synthesis of complexes [PdLCl2] (I) and [PdLBr2] (II) was successfully achieved,where L = 2,6-dimethyl-4-nitro-N-(pyridin-2-ylmethylildene)aniline, a ligand with a purported ability toinhibit monoamine oxidase B (MAO-B). To gain insight into the molecular structure of complexes Iand II, as well as the ligand precursor 2,6-dimethyl-4-nitroaniline L4 (CIF files CCDC nos. 2255106 (I),2255105 (II), 2255103 (L), 2255104 (L4)), X-ray diffraction analysis was utilized. Complex I underwent furthercharacterization to determine its stability, solubility, and lipophilicity. Cytotoxicity studies of substancesL, I, and II on human embryonic kidney cell line HEK-293 showed no evidence of cytotoxic activity. To evaluatethe inhibitory activity of new substances L, I, and II as well as established substances III−IX, selegiline,and rasagiline, ex vivo studies were conducted, establishing a structure/activity relationship.