1361152-41-1Relevant academic research and scientific papers
Synthesis, structure, and glutathione peroxidase-like activity of amino acid containing ebselen analogues and diaryl diselenides
Selvakumar, Karuthapandi,Shah, Poonam,Singh, Harkesh B.,Butcher, Ray J.
, p. 12741 - 12755 (2011/12/04)
The synthesis of some ebselen analogues and diaryl diselenides, which have amino acid functions as an intramolecularly coordinating group (Se O) has been achieved by the DCC coupling procedure. The reaction of 2,2′- diselanediylbis(5-tert-butylisophthalic acid) or the activated ester tetrakis(2,5-dioxopyrrolidin-1-yl) 2,2′-diselanediylbis(5-tert- butylisophthalate) with different C-protected amino acids (Gly, L-Phe, L-Ala, and L-Trp) afforded the corresponding ebselen analogues. The used precursor diselenides have been found to undergo facile intramolecular cyclization during the amide bond formation reaction. In contrast, the DCC coupling of 2,2′-diselanediyldibenzoic acid with C-protected amino acids (Gly, L/D-Ala and L-Phe) affords the corresponding amide derivatives and not the ebselen analogues. Some of the representative compounds have been structurally characterized by single-crystal X-ray crystallography. The glutathione peroxidase (GPx)-like activities of the ebselen analogues and the diaryl diselenides have been evaluated by using the coupled reductase assay method. Intramolecularly stabilized ebselen analogues show slightly higher maximal velocity (Vmax) than ebselen. However, they do not show any GPx-like activity at low GSH concentrations at which ebselen and related diselenides are active. This could be attributed to the peroxide-mediated intramolecular cyclization of the corresponding selenenyl sulfide and diaryl diselenide intermediates generated during the catalytic cycle. Interestingly, the diaryl diselenides with alanine (l,l or d,d) amide moieties showed excellent catalytic efficiency (kcat/KM) with low KM values in comparison to the other compounds. Peroxidase-like activity: Reaction of compound 1 (see figure) with glutathione (GSH) leads to the formation of the corresponding selenenyl sulfide and diaryl diselenide intermediates. The reaction of these intermediates with H2O2 leads to the formation of 1 via arylselenenic acid. This process hampers the GPx-like activity at low GSH concentrations.
