Speciation study and biological activity of copper (II) complexes with picolinic and 6-methylpicolinic acid with different components of blood serum of low molecular mass in KNO3 1.0 mol·L−1 at 25 °C

In the present work, the chemical speciation of ternary complexes of copper (II) with picolinic acid and 6-methylpicolinic acid and different ligands, such as, components of the blood plasma of low molecular mass (lactic acid, oxalic acid, citric acid, and phosphoric acid) were studied by measurements of emf(H) in KNO3 1.00 molL- 1. Potentiometric studies showed a predilection towards the formation of ternary species in solution, except for the copper (II)-picolinate-phosphate systems. The biological activity of the binary and ternary complexes isolated in situ, against reactive oxygen species was studied showing a concentration-dependent effect due to a possible mechanism of electron transfer. Finally, for the complexes Cu(Pic)2 and for the ligands were studied the ligand-receptor interaction on a PI3k of human origin by molecular docking, showing that, by themselves, the ligands are not capable of interacting with the active site of the enzyme. The metallic center is fundamental to generate reversible electrostatic interactions, that can be key to the indirect hypoglycemic effect exhibited by the Cu(Pic)2 complex reported in the literature

Chemical speciation, antioxidant activity and molecular docking of copper(II) complexes with pyridinedicarboxylic acids and different ligands of low molecular mass

Analyses of potentiometric measurements were conducted on ternary complexes of copper(II) with dipicolinic acid and quinolinic acid, as well as lactic acid, oxalic acid, citric acid, and phosphoric acid, which are components of blood plasma. Studies on chemical speciation showed that ternary compounds were more likely to be formed. In systems with quinolinic acid, the solubility was small, and most complexes precipitated at pH <= 2. In situ isolated ternary and binary complexes of CuDiPic(H2O)(2) were evaluated for antioxidant activity, as shown by their inhibiting activity of superoxide anion (O-2.(-)), which demonstrates copper(II) complexes provide protective effects. Docking studies of ligands with a protein kinase revealed that the Cu(II) metal centre is crucial for the successful interaction of the complex with the receptor's active site