New copper(II) complexes including pyridine-2,5-dicarboxylic acid: synthesis, spectroscopic, thermal properties, crystal structure and how these complexes interact with purified PON 1 enzyme

<p>We report the synthesis of two square-pyramidal copper(II) complexes, [Cu(2,5-pydc)(2-aepy)(H₂O)]·H₂O, <b>1</b>, and [Cu(2,5-pydc)(2-ampy)(H₂O)]·H₂O, <b>2</b> (2-aepy = 2-(aminoethyl)pyridine, 2-ampy = 2-(aminomethyl)pyridine, 2,5-pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid). The synthesized complexes have been characterized by X-ray diffraction, FT-IR, elemental, and thermal analysis techniques. The crystal structure of <b>1</b> was established by X-ray analysis. Powder X-ray diffraction analysis showed that the complexes are pure. The inhibition of human serum paraoxonase 1 (PON 1, EC 3.1.8.1) enzyme with these complexes were investigated. We used diethyl 4-nitrophenyl phosphate as a substrate to measure the paraoxonase activity of PON 1 enzyme spectrophotometrically. Complexes <b>1</b> and <b>2</b> decreased the <i>in vitro</i> PON 1 activity with different inhibition mechanisms. Complexes <b>1</b> and <b>2</b> inhibited paraoxonase activity of this enzyme as competitively and noncompetitively, respectively.</p

Synthesis, crystal structure, spectroscopy, thermal properties and carbonic anhydrase activities of new metal(II) complexes with mefenamic acid and picoline derivatives

<p>The mononuclear six metal(II) complexes ([Co(mef)₂(3-pic)₂(CH₃OH)₂] (<b>1</b>), [Ni(mef)₂(3-pic)₂(CH₃OH)₂] (<b>2</b>), [Cu(mef)₂(3-pic)₂] (<b>3</b>), [Co(mef)₂(4-pic)₂] (<b>4</b>), [Ni(mef)₂(4-pic)₂] (<b>5</b>), and [Cu(mef)₂(4-pic)₂] (<b>6</b>) with mefenamic acid and picoline ligands were synthesized, characterized, and their carbonic anhydrase inhibitory activities were evaluated. The six complexes were characterized by elemental analysis, FT-IR spectroscopy, and thermal analyses. The crystal structures of <b>1</b>, <b>3</b>, and <b>6</b> were determined by X-ray crystallography. The complexes have octahedral geometry. In <b>1</b>, the mefenamato ligand behaved as monodentate whereas in <b>3</b> and <b>6</b>, the mefenamato ligand acted as a bidentate ligand. Complexes <b>3</b> and <b>6</b> consist of the mefenamate and 4-picoline ligands. In <b>1</b>, unlike the other complexes, methanol acted as a ligand and was involved in the coordination. Carbonic anhydrase I and II isoenzymes were purified from human erythrocytes. The <i>in vitro</i> effects of mefenamic acid, 3-picoline, 4-picoline, and the six metal(II) complexes on these isoenzymes were evaluated.</p