Thiol modifier effects of diphenyl diselenides: insight from experiment and DFT calculations

Abstract

A combination of spectroscopic, chromatographic and computational approaches was employed to investigate the reaction of several diselenides of formula (R-PhSe)2 (R= CH3O, CH3, H, Cl, CF3) with a thiolate nucleophile,...

Solvent effect on the 77Se NMR chemical shifts of diphenyl diselenides

“…While all the intermediate discrepancies can be appreciated experimentally, it is unluckily challenging to capture them theoretically, even when refined approaches are used. Moreover, diphenyl diselenide is a tricky compound when it comes to chemical shift prediction, since the softness of the Se-Se bond and the free rotation of the phenyl rings lead to a plethora of accessible structures in solution, 80 and, as more recently reported, also in a protein environment. 81 During the NMR experiment, the chemical shift of all these structures is averaged out.…”

“…As a first approximation, we attempted to take this aspect into account in our calculation considering two different conformers identified in gas phase calculations in previous studies according to the different Φ ( C–C–Se–Se) dihedrals involving the diselenide bridge and the C–C bond of phenyl (Scheme 1). 80…”

“…As a first approximation, we attempted to take this aspect into account in our calculation considering two different conformers identified in gas phase calculations in previous studies according to the different F( C-C-Se-Se) dihedrals involving the diselenide bridge and the C-C bond of phenyl (Scheme 1). 80 According to the values of F, an 'open' and 'closed' conformation characterises the most stable conformers. The closed conformation corresponds to roughly F = 01 for both phenyl rings, while the open conformation corresponds to roughly F = 901 for all phenyl rings (Fig.…”

Role of Group 12 Metals in the Reduction of H2O2by Santi’s Reagent: A Computational Mechanistic Investigation

“…Although significant, the formation of 6 is not sufficient to explain the catalytic activity of 1-ZnCl that, as reported, is not just a precursor of a selenenic acid; indeed, the Zn center, as a Lewis acid, may play an active role. After its formation, 6 can react with GSH (which can be modeled as methyl thiol, MeSH, as chosen in previous studies − ) forming a selenosulfide; then, a second molecule of GSH/MeSH can in principle attack either the S or the Se center, but only the first event leads to the recovery of the initial catalyst. This is the most delicate step for designing efficient low-molecular-weight GPx mimic molecules, and in this framework, the action of the Zn center can be important to drive the nucleophilic attack.…”

A selenoureido-iminoglycolipid transported by zeolitic-imidazolate framework nanoparticles: a novel antioxidant therapeutic approach

“…4 It is not a coincidence that nature has chosen selenium due to its unique ability to react with oxygen and related ROS in a readily reversible manner, being able to both rapidly become oxidized and then be rapidly reduced (referred to as the ''selenium paradox''). 5 To mimic the intracellular GPx antioxidant activity, some organoselenium compounds 6 and selenium (Se)-containing nanomaterials 7 have been investigated with pharmacological purposes.…”