A Water‐Soluble Cyclic Selenide with Enhanced Glutathione Peroxidase‐Like Catalytic Activities

Abstract

Antioxidative catalytic activities of trans-3,4-dihydroxyselenolane (DHS red ), a water-soluble cyclic selenide, were investigated in the reaction of hydrogen peroxide with three different thiol substrates, monothiol glutathione (GSH), dithiol dithiothreitol (DTT red ), and polythiol reduced ribonuclease A (RNase A) having eight thiol groups along the polypeptide chain. For all the thiol substrates, DHS red exhibited higher glutathione peroxidase (GPx)-like antioxidative catalytic ac-

Reactivity of selenium-containing compounds with myeloperoxidase-derived chlorinating oxidants: Second-order rate constants and implications for biological damage

“…This reactivity is similar to that reported for various peroxides, which have been shown to preferentially oxidize SeMet in the presence of the thiol-containing targets GSH or Met [43]. However, the second-order rate constants for the peroxide reactions suggest that the selenium compounds would be more effective scavengers of hypohalous acids with k2 > 10 7 M -1 s -1 [27] and N-chloramines with k2 > 10 2 M -1 s -1 , than peroxides where the rate is ~ 10 2 M -1 s -1 for similar compounds [30]. Thus, selenium compounds may act as competitive in vivo scavengers of N-chloramines and other MPO-derived oxidants.…”

“…For example, selenomethionine (SeMet) and 1,4-anhydro-4-seleno-D-talitol (SeTal) react with HOCl with second-order rate constants >10 8 M -1 s -1 , comparable to the second-order rate constants for reaction of HOCl with GSH and Cys [7,27]. In addition, ebselen and SeMet, both selenoethers, have demonstrated ability to detoxify peroxides and peroxynitrous acid, forming an oxidized 7 selenium compound, which can be reduced by GSH, giving a catalytic scavenging cycle analogous to that of glutathione peroxidase (GPx) [28][29][30].…”

Water-dependent synthesis of biologically active diaryl diselenides

“…45 Time of conversion of dithiol (DTT red ) to a disulphide (DTT ox ) in the presence of H2O2 and 10% of selenocatalyst was measured in selected time intervals ( Table 2). The highest activity was obtained for benzisoselenazolone 14 with an additional methoxy moiety.…”

“…The crude product was purified by multiple rinsing with boiling DCM. 45 To a solution of compounds 1, 2, 9-20 (0.015 mmol) and dithiothreitole DTT red (0.15 mmol) in 1.1mL of CD3OD 30% H2O2 (0.15 mmol) was added. 1 H NMR spectra were measuared right after addition of hydrogen peroxide and then in specific time intervals.…”

Catalytic application of selenium and tellurium compounds as glutathione peroxidase enzyme mimetics

“…29 Very recently, Iwaoka et al trans-3,4-dihydroxyselenolane 33, a water soluble cyclic selenide. 30 Although the observed GPx like catalytic activities were not so remarkable as those of previous GPx model compounds, the water solubility of 33 certainly would be useful not only for the molecular design of new GPx mimics with enhanced antioxidative catalytic activity but also for biological applications as an efficient catalyst for the formation of sulfur-sulfur linkages in proteins.…”