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3-Mercaptopyruvic Acid
3-Mercaptopyruvic acid is an intermediate in cysteine metabolism. It has been studied as a potential treatment for cyanide poisoning, but its half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ... is too short for it to be clinically effective. Instead, prodrugs, such as sulfanegen, are being evaluated to compensate for the short half-life of 3-mercaptopyruvic acid. See also * 3-mercaptopyruvate sulfurtransferase References Carboxylic acids Thiols Alpha-keto acids {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine Metabolism
Cysteine metabolism refers to the biological pathways that consume or create cysteine. The pathways of different amino acids and other metabolites interweave and overlap to creating complex systems.cysteine is metabolism creating complex systems Human cysteine metabolism In human cysteine metabolism, L-cysteine is consumed in several ways as shown below. L-Cysteine is also consumed in methionine and glutathione metabolism as well as pantothenate/coenzyme A biosynthesis. L-Cysteine is the product of several processes as well. In addition to the reactions below, L-cysteine is also a product of glycine, serine, and threonine metabolism. See also * D-cysteine desulfhydrase * Sulfur metabolism Sulfur is metabolism, metabolized by all organisms, from bacteria and archaea to plants and animals. Sulfur is redox, reduced or redox, oxidized by organisms in a variety of forms. The chemical element, element is present in proteins, organosulfate ... {{DEFAULTSORT:Cysteine Metabolism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanide Poisoning
Cyanide poisoning is poisoning that results from exposure to any of a number of forms of cyanide. Early symptoms include headache, dizziness, fast heart rate, shortness of breath, and vomiting. This phase may then be followed by seizures, slow heart rate, low blood pressure, loss of consciousness, and cardiac arrest. Onset of symptoms usually occurs within a few minutes. Some survivors have long-term neurological problems. Toxic cyanide-containing compounds include hydrogen cyanide gas and a number of cyanide salts. Poisoning is relatively common following breathing in smoke from a house fire. Other potential routes of exposure include workplaces involved in metal polishing, certain insecticides, the medication sodium nitroprusside, and certain seeds such as those of apples and apricots. Liquid forms of cyanide can be absorbed through the skin. Cyanide ions interfere with cellular respiration, resulting in the body's tissues being unable to use oxygen. Diagnosis is often diffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Half-life
Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma, and is denoted by the abbreviation t_. This is used to measure the removal of things such as metabolites, drugs, and signalling molecules from the body. Typically, the biological half-life refers to the body's natural cleansing through the function of the liver and through the excretion of the measured substance through the kidneys and intestines. This concept is used when the rate of removal is roughly exponential. In a medical context, half-life explicitly describes the time it takes for the blood plasma concentration of a substance to halve (''plasma half-life'') its steady-state when circulating in the full blood of an organism. This measurement is useful in medicine, pharmacology and pharmacokinetics because it helps det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prodrug
A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug is absorbed, distributed, metabolized, and excreted (ADME). Prodrugs are often designed to improve bioavailability when a drug itself is poorly absorbed from the gastrointestinal tract. A prodrug may be used to improve how selectively the drug interacts with cells or processes that are not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. History Many herbal extracts historically used in medicine contain glycosides (sugar derivatives) of the active agent, which are hydrolyzed in the intestines to release the active and more bioavailable aglycone. For example, salicin is a β-D-glucopyranosid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfanegen
Sulfanegen is an experimental antidote for cyanide poisoning. It is being studied as a prodrug for 3-mercaptopyruvic acid (3-MP). 3-MP has been studied as a potential treatment for cyanide poisoning, but the half-life is too short for it to be clinically effective. Instead, alternative chemicals such as sulfanegen, the hemithioacetal cyclic dimer of 3-MP, are being evaluated that produce 3-MP in vivo to compensate for the short half-life of 3-MP itself. Sulfanegen has been shown to be effective in animal studies. It is being studied as the disodium salt, sulfanegen sodium, and the triethanolamine salt, sulfanegen TEA. One advantage various sulfanegen formulations have over existing treatments for acute cyanide poisoning is that they might be administered by intramuscular injection or orally rather than by intravenous infusion Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-mercaptopyruvate Sulfurtransferase
In enzymology, a 3-mercaptopyruvate sulfurtransferase () is an enzyme that catalyzes the chemical reactions of 3-mercaptopyruvate. This enzyme belongs to the family of transferases, specifically the sulfurtransferases. This enzyme participates in cysteine metabolism. It is encoded by the ''MPST'' gene. The enzyme is of interest because it provides a pathway for detoxification of cyanide, especially since it occurs widely in the cytosol and distributed broadly. Nomenclature The systematic name of this enzyme class is 3-mercaptopyruvate:cyanide sulfurtransferase. This enzyme is also called beta-mercaptopyruvate sulfurtransferase and in the older literature, human liver rhodanese. Structure Gene The ''MPST'' gene lies on the chromosome location of 22q12.3 and consists of 6 exons. Alternatively spliced transcript variants encoding the same protein have been identified. Protein The encoded cytoplasmic protein is a member of the rhodanese family but is not rhodanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylic Acids
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion. Examples and nomenclature Carboxylic acids are commonly identified by their trivial names. They at oftentimes have the suffix ''-ic acid''. IUPAC-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix. For example, butyric acid (C3H7CO2H) is butanoic acid by IUPAC guidelines. For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the parent chain even if there are other substituents, such as 3-chloropropanoic acid. Alternately, it can be named as a "carboxy" or "carboxylic acid" substituent on another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiols
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the "smell of natural gas" is due to the smell of the thiol used as the odorant. Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate group () bonds very strongly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
