69612-65-3Relevant academic research and scientific papers
Rates of Oxidation of o-Nitrobenzeneselenenyl Compounds by m-Chloroperoxybenzoic Acid and the Rate of Reaction of o-Nitrobenzeneselenol with o-Nitrobenzeneselenenic Acid
Kice, John L.,Chiou, Shishue
, p. 290 - 294 (1986)
Rate constants for the oxidation of a series of o-nitrobenzeneselenenyl derivatives (Ar = o-O2NC6H4) by m-chloroperoxybenzoic acid (MCPBA) have been measured at 25 deg C in ethanol (compound, kPA (M-1s-1)): ArSeH, 1.1 * 104; ArSeOH, 80; ArSeOSeAr, 12; ArSeOEt, 4; ArSeSeAr, 0.15.The rate constant (kArSeH = 1.0 * 102 M-1s-1) for the reaction of ArSeH with ArSeOH to give ArSeSeAr (eq 3), which is pH independent in acid solution, has also been determined.Significant practical consequences of these and related results include the following: (a) the rate of oxidation of selenol (ArSeH) to selenenic acid (ArSeOH) is enough faster than either the oxidation of ArSeOH to seleninic acid (ArSeO2H) or eq 3 so that oxidation of the selenol with 1 molar equiv of MCPBA gives ArSeOH in high yield; (b) with a weaker oxidant, hydrogen peroxide, the rate of oxidation of the selenol is enough slower than the rate of eq 3 that the diselenide (ArSeSeAr) becomes the almost exclusive product; (c) the rate of oxidation of the diselenide is so much smaller than that of any of the other compounds that its initial oxidation to ArSeOSeAr is far and away the slowest step in its overall oxidation to seleninic acid by excess peracid.
Selenols are resistant to irreversible modification by HNO
Bianco, Christopher L.,Moore, Cathy D.,Fukuto, Jon M.,Toscano, John P.
, p. 71 - 78 (2016/08/09)
The discovery of nitric oxide (NO) as an endogenously generated signaling species in mammalian cells has spawned a vast interest in the study of the chemical biology of nitrogen oxides. Of these, nitroxyl (azanone, HNO) has gained much attention for its potential role as a therapeutic for cardiovascular disease. Known targets of HNO include hemes/heme proteins and thiols/thiol-containing proteins. Recently, due to their roles in redox signaling and cellular defense, selenols and selenoproteins have also been speculated to be additional potential targets of HNO. Indeed, as determined in the current work, selenols are targeted by HNO. Such reactions appear to result only in formation of diselenide products, which can be easily reverted back to the free selenol. This characteristic is distinct from the reaction of HNO with thiols/thiolproteins. These findings suggest that, unlike thiolproteins, selenoproteins are resistant to irreversible oxidative modification, support that Nature may have chosen to use selenium instead of sulfur in certain biological systems for its enhanced resistance to electrophilic and oxidative modification.
