The Nrf2 (NFE2L2) cell defense pathway protects against oxidative stress and disorders including cancer and neurodegeneration. Although activated modestly by oxidative stress alone, robust activation of the Nrf2 defense mechanism requires the additional presence of co-factors that facilitate electron exchange. Various molecules exhibit this co-factor function, including sulforaphane from crucif...

The reversible boronate formation between electrochemically active substituted catechols and a fluorescent boronic acid was studied in methanol.

We report that an amphiphilic bis-catechol (3) functions as a transmembrane anion transporter. Activity depends on the catechol's substitution and amphiphilicity. We also describe a liposomal assay that allows one to readily measure anion transport selectivity. This assay reveals that anion transport selectivity for this amphiphilic bis-catechol follows a Hofmeister sequence wherein anions that...

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-( - )-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. Th...

It has been traditionally considered that catechols release iron from ferritin by reduction to iron(II), which diffuses through the ferritin channels into the intracellular milieu where it participates in the Fenton reaction, producing highly toxic hydroxyl radicals. However, in the present work we have proved that the mechanism of the release of iron from ferritin by catechol does not take pla...

Either chemical or enzymatic oxidation of catechols or catecholamines in the presence of nucleophiles (amino acids, peptides, and proteins) leads to the production of ring-substituted o-semiquinones which have been detected by ESR spin stabilization techniques. In many cases, radicals have been completely characterized and structures assigned. Chemical considerations point to a mechanism involv...

Electrochemical oxidation of the catechols 1a and 1b is studied in the presence of 6-methyl-2-thouracil (3b) and 6-propyl-2-thiouracil (3a) as nucleophiles in a phosphate buffer (0.15 mol L−1, pH = 6.8)/DMF (95:5) solution using cyclic voltammetry and controlled-potential coulometry. The results obtained indicate that the quinones derived from the catechols participate in 1,4-Michael-addition r...