New Pyrazole-Hydrazone Derivatives: X-ray Analysis, Molecular Structure Investigation via Density Functional Theory (DFT) and Their High In-Situ Catecholase Activity

• Published in: International journal of molecular sciences Vol. 18; no. 11; p. 2215
• Main Authors: Karrouchi, Khalid, Yousfi, El Bekkaye, Sebbar, Nada Kheira, Ramli, Youssef, Taoufik, Jamal, Ouzidan, Younes, Ansar, M'hammed, Mabkhot, Yahia N, Ghabbour, Hazem A, Radi, Smaail
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.10.2017; MDPI
• Subjects: Biochemistry; Biomolecules; Catalysis; Catalysts; Catalytic activity; Catechol; Catechol oxidase; catecholase activity; Copper compounds; Crystal structure; Density functional theory; DFT; Enzymes; hydrazone; Ligands; Molecular structure; Oxidation; Pyrazole; Quinones; Single crystals; Tyrosinase; X ray analysis; X-rays; crystal structure; pyrazole; DFT; hydrazone; catecholase activity
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms18112215

The development of low-cost catalytic systems that mimic the activity of tyrosinase enzymes (Catechol oxidase) is of great promise for future biochemistry technologic demands. Herein, we report the synthesis of new biomolecules systems based on hydrazone derivatives containing a pyrazole moiety ( - ) with superior catecholase activity. Crystal structures of and biomolecules were determined by X-ray single crystal diffraction (XRD). Optimized geometrical parameters were calculated by density functional theory (DFT) at B3LYP/6-31G (d, p) level and were found to be in good agreement with single crystal XRD data. Copper (II) complexes of the compounds ( - ), generated in-situ, were investigated for their catalytic activities towards the oxidation reaction of catechol to -quinone with the atmospheric dioxygen, in an attempt to model the activity of the copper containing enzyme tyrosinase. The studies showed that the activities depend on four parameters: the nature of the ligand, the nature of counter anion, the nature of solvent and the concentration of ligand. The Cu(II)-ligands, given here, present the highest catalytic activity (72.920 μmol·L ·min ) among the catalysts recently reported in the existing literature.