RESUMO
BACKGROUND: Antioxidant, anti-inflammatory, antiviral and antitumoral activities among others are essential characteristics in the development of novel therapeutic compounds. Acid hydrazides can form complexation with certain metal ions that positively enhance these biological characteristics. OBJECTIVE: Five new complexes of uranium with hydrazide ligands were synthesized at room temperature. METHODS: The characterization was done by spectroscopic methods (ESI-Mass, IR, 1H-NMR, 13CNMR), CHN analysis and conductivity measurements. Metal complexes along with their respective ligands were further screened for their antioxidant (DPPH, superoxide and nitric oxide free radicals) properties and enzyme inhibition (α-glucosidase) activities. RESULTS: Elemental and spectral data indicate octahedral geometry around uranyl (UO2 2+) species. Magnetic moments indicate the diamagnetic nature of uranyl(VI) ion in the complex in solid state. IC50 values showed potential antioxidant behavior of uranyl complexes demonstrating interesting structure-activity relationships. In general, hydrazide ligands were not active against superoxide and nitric oxide radicals while varying degree of results were observed against DPPH radical whereas all uranyl-complexes showed promising radical scavenging activities against all of them. Promising inhibitory potential was displayed by UO2 +2 hydrazide complexes against α- glucosidases whereas free hydrazide ligands were inactive. CONCLUSION: Structure function relationship demonstrates that the nature of ligand, position of substituent, electronic and steric effects are significant factors affecting the radical scavenging and enzyme inhibition activities of the compounds.
Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Hidrazinas/química , Urânio/química , alfa-Glucosidases/metabolismo , Compostos de Bifenilo/química , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Concentração Inibidora 50 , Óxido Nítrico/química , Picratos/químicaRESUMO
The present study explores the synthesis and inhibitory potential of vanadium(V) complexes of hydrazides (1c-12c) against oxidative enzymes including xanthine oxidase and lipoxygenase (LOX). In addition, non-enzymatic radical scavenging activities of these complexes were also determined. On the basis of spectral, elemental and physical data, synthesized vanadium(V) complexes are tentatively assigned to have an octahedral geometry with two hydrazide ligands and two oxo groups forming a negatively charged sphere complex with ammonium as counter ion. This is further verified by the conductivity studies of the complexes. Results show that hydrazide ligands (1-12) and their respective vanadium(V) complexes (1c-12c) posses scavenging and inhibition potential against DPPH and LOX, respectively. However, contrary to that uncoordinated ligands showed no activity against nitric oxide, superoxide and xanthine oxidase whereas their complexes showed varying degree of activity. These studies indicate that geometry of complex, nature and position of substituent groups play a vital role in scavenging and inhibition potential of these compounds.