Cysteine thiosulfate

Vitamin Bn-deficient P. shermanii grows well under strictly anaerobic conditions. However, under microaerophilic conditions compounds containing reduced sulfur methionine, cysteine, thiosulfate, reduced glutathione, or tryptone must be added to the medium (Fig. 5.3) (Vorobjeva and Iordan, 1976). These compounds are necessary to prevent the oxidation of thiol groups. A direct determination showed (Iordan et al., 1974) that the... 

Although molybdenum is an essential element, excess levels can have deleterious effects. The LD q and TLV values of the most common Mo compounds are Hsted in Table 3 (63,64). In general the toxicity of Mo compounds is considered to be low. For example, M0S2 has been found to be virtually nontoxic even at high levels. Certain Mo compounds such as MoCl and Mo(CO), have higher toxicity because of the chemical nature and reactivity of these compounds rather than the Mo content. Supplementary dietary Cu ", thiosulfate, methionine, and cysteine have been shown to be effective in alleviating Mo toxicity in animals. 

Permanent coloration can also be achieved by exposing hair to certain metals copper, silver, and especially lead salts. Preparations containing aqueous solutions of lead acetate may include a source of sulfur, usually thiosulfate, which may react with cystine in the hair to produce some cysteine or may react directiy with the metal ion to form dark metallic sulfides. Preparations of this type, which darken hair gradually, are not universally considered safe. 

Persulfate (41) reacts with transition metal ions (e.g. Ag, Fe21, Ti31) according to Scheme 3.42. Various other reduetants have been described. These include halide ions, thiols (e.g. 2-mercaptoethanol, thioglycolic acid, cysteine, thiourea), bisulfite, thiosulfate, amines (triethanolamine, tetramethylethylenediamine, hydrazine hydrate), ascorbic acid, and solvated electrons (e.g. in radiolysis). The mechanisms and the initiating species produced have not been fully elucidated for... 

Gut I, Nerudova J, Kopecky J, et al. 1975. Acrylonitrile biotransformation in rats, mice, and Chinese hamsters as influenced by the route of administration and by phenobarbital, SKF 525-A, cysteine, dimercaprol, or thiosulfate. Arch Toxicol 33 151-161. 

HCN is detoxified to thiocyanate (SCN ) by the mitochondrial enzyme rhodanese rhodanese catalyzes the transfer of sulfur from thiosulfate to cyanide to yield thiocyanate, which is relatively nontoxic (Smith 1996). The rate of detoxification of HCN in humans is about 1 pg/kg/min (Schulz 1984) or 4.2 mg/h, which, the author states, is considerably slower than in small rodents. This information resulted from reports of the therapeutic use of sodium nitroprusside to control hypertension. Rhodanese is present in the liver and skeletal muscle of mammalian species as well as in the nasal epithelium. The mitochondria of the nasal and olfactory mucosa of the rat contain nearly seven times as much rhodanese as the liver (Dahl 1989). The enzyme rhodanese is present to a large excess in the human body relative to its substrates (Schulz 1984). This enzyme demonstrates zero-order kinetics, and the limiting factor in the detoxification of HCN is thiosulphate. However, other sulfur-containing substrates, such as cystine and cysteine, can also serve as sulfur donors. Other enzymes, such as 3-mercapto-pyruvate sulfur transferase, can convert... 

In order to obtain heterodimers a cysteine residue of one peptide has to be specifically activated for subsequent reaction with the cysteine residue of the second peptide. Thiols are activated by introducing an electron-withdrawing substituent that increases the responsiveness of the sulfur to nucleophilic substitution. This topic has been reviewed 41311 Of the various older methods known in sulfur chemistry for the preparation of unsymmetrical disulfides, i.e. thiosulfates,11321 S-alkylthiosulfonates,11331 5-alkylthiosulfinates,11341 sulfanyl-amines,11351 sulfanylimides,11361 sulfanyl thiocyanates and sulfenyl chlorides,1137,1381 sulfan-... 

An important property of 3-mercaptopyruvate arises from electron withdrawal by the carbonyl group. This makes the SH group electrophilic and able to be transferred as SH+, S°, to a variety of nucleophiles (Eq. 24-44). Thus sulfite yields thiosulfate (S2032 + H+, Eq. 24-45, step a), cyanide yields thiocyanate (Eq. 24-45, step b), and cysteine sulfinate yields alanine thiosulfonate.448 461 The reactions are catalyzed by mercaptopyruvate sulfurtransferase, an enzyme very similar to thiosulfate sulfurtransferase. The latter is a liver enzyme often called by the traditional... 

SULFUR (In Biological Systems). Sulfur, in some form, is required by all living organisms. It is utilized in various oxidation stales, including sulfide, elemental sulfur, sulfite, sulfate, and thiosulfate by lower forms and in organic combinations by all. The more important sulfur-containing organic compounds include the amino acids (cysteine, cystine, and methionine, which are components of proteins) the vitamins thiamine and... 

The activity of sulfur towards platinum complexes has led to investigation of so-called rescue agents to ameliorate the side effects of platinum therapy, without compromising its anti-tumor activity. These nucleophilic sulfur compounds include sodium thiosulfate (STS), sodium diethyldithio-carbamate (Naddtc), (S)- 2-[(3-aminopropyl)amino]ethyl phosphorothioic acid (WR-2721, Ethyol , amifostine), glutathione (GSH), methionine, thiourea, cysteine, -acetylcysteine, penicillamine, biotin, sulfathiazole, sodium 2-mercaptoethanesulfonate (mesna), and its dimer (di)mesna (BNP-7787). The protective effect of these compounds is either due to prevention, or reversal of Pt-S adducts in proteins. Some of the more promising of the above-mentioned compounds (see Fig. 1) will be discussed below. 

Chloramines are themselves mild oxidants capable of reacting with —SH groups of glutathione (GSH), cysteine, thioether groups of methionine, and other thiol compounds, including thiosulfate, which reduce chloramines to Cl ion and reconstitute the amino moiety ... 

Zhang, Z., Riviere, J.E., Monteiro-Riviere, N.A. (1995b). Evaluation of protective effects of sodium thiosulfate, cysteine, niacinamide and indomethacin on sulfur mustard-treated isolated perfused porcine skin. Chem. Biol. Interact. 96 249-62. 

Streptomycin was inactivated by reducing and oxidizing agents. The bacteriostatic-activity of this antibiotic for Escherichia coli was reduced in the presence of cysteine, sodium thioglycolate, stannous chloride, sodium bisulfite, sodium hydrosulfide, sodium formate and sodium thiosulfate. Cysteine was the most active. Denkelwater, Cook and Tishler found that the cysteine inactivation of streptomycin could be reversed by iodine presumably cystine was formed during this process. Rake and Donovick inactivated streptomycin with semi-carbazide hydrochloride in order to test the sterility of concentrated streptomycin solutions. The inactivation of streptomycin by compounds containing sulfhydryl groups has been discussed by Cavallito. ... 

Sulfhydryl compounds cause significant reductions in the activity of bronopol, and cysteine hydrochloride may be used as the deactivating agent in preservative efficacy tests lecithin/ polysorbate combinations are unsuitable for this purpose. Bronopol is incompatible with sodium thiosulfate, with sodium metabisulfite, and with amine oxide or protein hydrolysate surfactants. Owing to an incompatibility with aluminum, the use of aluminum in the packaging of products that contain bronopol should be avoided. 

The use of common antioxidants, such as water-soluble sodium bisulfate, sodium sulfite, sodium metabisulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, L- and D-ascorbic acid, acetylcysteine, cysteine, thioglycerol, thioglycollic acid, thiolactic acid, thiourea, dithithreitol or oil-soluble propyl gallate, butylated hydroxyanisole, butylated hydroxytoluene, ascorbyl palmitate, nordihydroguaiaretic add, and a-tocopherol is widely made in pharmaceutical formulations. Oxygen-sensitive substances should be screened for their compatibility with a range of antioxidants. One of the most commonly used antioxidants is metabisulfite. It should be noted that bisulfite has also been known to catalyze... 

Ellman and coworkers have also reported the use of these resin-bound isocyanates for the scavenging of thiols in the parallel synthesis of a small library of cysteine protease inhibitors (Scheme 8.3) [7]. Simple filtration afforded the hydroxy sulfide products in moderate to good yields. Excess Dess-Martin periodinane, as well as the by-product in the final step, were scavenged using a resin-bound thiosulfate to yield target compounds. 

Genetic deficiency of sulfite oxidase in humans develops in early infancy, with lethal outcome at the age of 2-3 years. The condition is associated with high urinary output of sulfite, thiosulfate and S-sulfo-L-cysteine, along with a marked decrease in urinary sulfate. The diseased... 

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