Hydroxyl Radical Generation and DNA Nuclease Activity: A Mechanistic Study Based on a Surface-Immobilized Copper Thioether Clip-Phen Derivative.
Coordination compounds of copper have been invoked as major actors in processes involving the reduction of molecular oxygen, mostly with the generation of radical species the assignment for which has, so far, not been fully addressed. In the present work, we have carried out studies in solution and on surfaces to gain insights into the nature of the radical oxygen species (ROS) generated by a copper(II) coordination compound containing a thioether clip-phen derivative, 1,3-bis(1,10-phenanthrolin-2-yloxy)-N-(4-(methylthio)benzylidene)propan-2-amine (2CP-Bz-SMe), enabling its adsorption/immobilization to gold surfaces. Whereas surface plasmon resonance (SPR) and electrochemistry of the adsorbed complex indicated the formation of a dimeric Cu(I) intermediate containing molecular oxygen as a bridging ligand, scanning electrochemical microscopy (SECM) and nuclease assays pointed to the generation of a ROS species. Electron paramagnetic resonance (EPR) data reinforced such conclusions, indicating that radical production was dependent on the amount of oxygen and H2 O2 , thus pointing to a mechanism involving a Fenton-like reaction that results in the production of OH(.) .
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil.
Adolfo I B
http://orcid.org/0000-0002-9288-2420
AI
Romo
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil.
Dieric S
DS
Abreu
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil.
Tércio
http://orcid.org/0000-0001-6815-7547
T
de F Paulo
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil.
Marta S P
MS
Carepo
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil.
Eduardo H S
http://orcid.org/0000-0002-0007-8452
EH
Sousa
Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Estación Central, Santiago, Chile.
Luis
http://orcid.org/0000-0002-5499-8115
L
Lemus
Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Estación Central, Santiago, Chile.|Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Santiago, Chile.
Carolina
C
Aliaga
Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP, 13565-905, São Carlos, SP, Brazil.
Alzir A
AA
Batista
Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, CEP, 13560-970, São Carlos, SP, Brazil.
Otaciro R
OR
Nascimento
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853-1301, USA. hda1@cornell.ed.
Héctor D
http://orcid.org/0000-0002-3948-356X
HD
Abruña
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Cx. Postal 6021, Fortaleza, CE, 60451-970, Brasil. Izaura@dqoi.ufc.br.
Izaura C N
http://orcid.org/0000-0002-2765-4982
IC
Diógenes
D001669:Biochemical Phenomena; D003300:Copper / Q000737:chemistry*; D003851:Deoxyribonucleases / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
C115240:Clip-phen; D008024:Ligands; D009942:Organometallic Compounds; D010618:Phenanthrolines; D013440:Sulfides; D017665:Hydroxyl Radical; D003300:Copper; D003851:Deoxyribonucleases
coordination modes; copper; radicals; reaction mechanisms; reactive intermediates