Facilitation of electrochemical oxidation of dialkyl sulfides appended with neighboring carboxylate and alcohol groups

Electron Transfer in Peptides with Cysteine and Methionine as Relay Amino Acids

“…This finding can be explained by a neighboring group effect of the adjacent amide function, which has been demonstrated, for example, by the norbornene systems 8 and 9: the endo amide group in 9 reduces the redox potential by 0.55 V compared to that of 8. [18] Schöneich and co-workers [16] have studied such an effect in detail and suggested that the stabilization by a neighboring amide group makes methionine a target for oxidative stress.…”

Sensorically and antimicrobially active metabolite production of Lactobacillus strains on Jerusalem artichoke juice

“…Nevertheless, methionine17 turned out to be an efficient relay amino acid, with 20 % of tyrosyl radical 3 f being generated 40 ns after the laser flash (Table 1, entry 6). This finding can be explained by a neighboring group effect of the adjacent amide function, which has been demonstrated, for example, by the norbornene systems 8 and 9 : the endo amide group in 9 reduces the redox potential by 0.55 V compared to that of 8 18. Schöneich and co‐workers16 have studied such an effect in detail and suggested that the stabilization by a neighboring amide group makes methionine a target for oxidative stress.…”

Hole Hopping through Tryptophan in Cytochrome P450

“…At the periphery of this potential window proteins present a decidedly unsymmetrical medium for electron transfer (ET). Whereas reduction of peptides and small aromatic groups only proceeds at potentials more negative than −2.5 V vs NHE, − one-electron oxidations of aromatic and sulfur-containing amino-acids, as well as the peptide backbone itself, can occur at potentials in the 1.0–1.5 V vs NHE range. − We anticipate, then, that proteins are superexchange mediators of ET in reactions of low-potential redox couples. In contrast, oxidized amino acid radicals are known to be essential participants in many high-potential enzymatic redox reactions, − and structural evidence suggests that they may play a far greater role than previously recognized …”