Peroxidase activity of new mixed‐valence cobalt complexes with ligands derived from pyridoxal

Abstract

New mixed‐valence cobalt complexes with ligands derived from pyridoxal were synthesized and characterized, and their application as mimetics of the peroxidase enzyme was investigated. Single‐crystal X‐ray diffraction was used to analyze all complex structures in the solid state and their electrochemical behavior was investigated. A reactivity pattern was observed in the complex synthesis regarding the cobalt compounds from which analogous zwitterionic derivatives were obtained. The importance of these compounds lies in understanding their behavior in an oxidizing environment and evaluating whether they can activate hydrogen peroxide to oxidize phenolic compounds. In nature, enzymes called peroxidases, which efficiently oxidize phenolic compounds, trigger many reactions involving the activation of hydrogen peroxide to oxidize organic substrates. However, these enzymes present several disadvantages, including denaturation and elevated costs. Therefore, these limitations can be overcome by expanding research into the study of synthetic catalysts for the oxidation of phenolic compounds using hydrogen peroxide, which is a highly relevant field of bioinorganic chemistry.

Enzymatic Dimerization‐Induced Self‐Assembly of Alanine‐Tyramine Conjugates into Versatile, Uniform, Enzyme‐Loaded Organic Nanoparticles

“…When glucose (the bioanalyte) was added to GOx/HRP@NPs, we found that it could catalyze the cascade redox reactions quite well at ambient conditions and generate spectroscopic signals with a wide variety of redox substrates viz . TMB, [49] OPD, [50] ABTS, [51] DCFDA, [52] Amplex red assay, [53] AuNPs/AgNPs formation, [54] and turbidimetry assay (Figure S23–S28). Various control experiments were employed to support the ox‐TMB formation only in the presence of glucose (Figure S29).…”

A highly selective pyridoxal-based chemosensor for the detection of Zn(ii) and application in live-cell imaging; X-ray crystallography of pyridoxal-TRIS Schiff-base Zn(ii) and Cu(ii) complexes

“…This suggests that pyridoxaldehyde is biocompatible and can be readily used in bio-applications. Several Schiffbases based on pyridoxaldehyde have been reported in the literature that forms complexes with a wide variety of metal cations, including transition metals, [33][34][35][36][37][38][39][40][41][42][43] heavy metals, 44,45 lanthanides, [46][47][48][49] and actinides. [49][50][51] However, only a few reports show pyridoxal-based Schiff-bases act as uorometric or colorimetric chemosensors for the detection of transition metals, biomolecules, and anions.…”