Oxides thiols

Transition metals such as iron can catalyze oxidation reactions in aqueous solution, which are known to cause modification of amino acid side chains and damage to polypeptide backbones (see Chapter 1, Section 1.1 Halliwell and Gutteridge, 1984 Kim et al., 1985 Tabor and Richardson, 1987). These reactions can oxidize thiols, create aldehydes and other carbonyls on certain amino acids, and even cleave peptide bonds. The purposeful use of metal-catalyzed oxidation in the study of protein interactions has been done to map interaction surfaces or identify which regions of biomolecules are in contact during specific affinity binding events. 

The 3-methyl- and 3-phenyl-l,2,3-oxadiazolinium salts 96 and 97 are capable of oxidizing thiols to disulfides <1995MI817>. New dihydro-1,2,3-benzoxadiazoles, prepared by the reaction of 1,2-benzoquinones with diethyl azodicarboxylate (DEAD) or diisopropyl azodicarboxylate (DIAD) in the presence of triphenylphosphine (Section 5.03.9.4), have been shown to undergo catalytic hydrogenolysis to give phenols (Equation 12) <20050L5139>. 

Oxidize thiol to form sulfonic acid, RSO3H, (HNO3)... 

Oxide Thiol T(K) FAST (M S 2(slow) (M s l(slow) (s Reference... 

Like its monomeric counterpart, the polymeric reagent is inert to simple amines, amides, alcohols and phenols, but easily oxidizes thiols to disulphides, phosphines to phosphine oxides, hydroquinone and catechol to quinones, and thioketones, thioesters and trithiocar-bonates to the corresponding 0x0 derivatives, in dichloromethane, chloroform or acetic... 

Like p-methoxyphenyl teUuroxide, tellurinic anhydrides do not affect phenols but oxidize hydroquinones to the corresponding quinones, and oxidize thiols, thioesters, thioamides and phosphines to disulphides, esters, nitriles and phosphine oxides. 

It was also demonstrated that acute exposure to diphenyl ditelluride did not change [ H]glutamate release and uptake by rat brain synaptosomes. In contrast, in vitro experiments indicate that 100 am of diphenyl ditelluride clearly inhibit [ H]glutamate uptake by brain synaptosomes and synaptic vesicles. These results also suggested that the inhibitory effect on glutamate uptake may be related, at least in part, to the ability of this compound to oxidize thiol groups. ... 

The pyridine oxide thiol complex (45) has been used as a fungicide in wood protection.136... 

Although PCC oxidizes thiols to disulfides308 and sulfides to sulfoxides,309 it is possible to selectively oxidize alcohols in the presence of sulfides.310,311... 

Oxidation of sulfur is called S-oxidation. Thiols can be oxidized to form disulfides ... 

The dihalides are susceptible to decomposition by hydrolysis. The dibromides oxidize thiols to disulfides, selenols to diselenides, and diphenyl tellurium to diphenyl tellurium oxide. Hydrazine reduces the dihalides to the parent compounds1. 

Oxidizing agents Halogens Oxidize thiol groups to disulphides, sulphox-ides or disulphoxides... 

Peroxygens Hydrogen peroxide activity results from formation of free hydroxyl radicals ( OH) which oxidize thiol groups in enzymes and proteins Peracetic acid disrupts thiol groups in proteins and enzymes... 

Metal ions of higher oxidation states, such as Fe , Ce, Co and oxidize thiols effectively... 

Little has so far been reported on the chemistry of teUurones. The preparation of several dialkyl tellurones by H2O2 or air oxidation of the corresponding tellurides or telluroxides has been claimed, but it is doubtful whether those compounds were isolated in a pure tellurone form. In 1982 the first definitely characterized tellurone, bis(4-methoxyphenyl) tellurone (60), was prepared by periodate oxidation of the corresponding telluroxide (59 equation 50). Both (59) and (60) woric as mild useful oxidants which show some chemoselectivities and readily oxidize thiols to disulfides. The preparation of dodecyl 4-methoxyphenyl tellurone by a similar method has also been claimed. ... 

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