In chemistry , peroxides are a group of compounds with the structure R−O−O−R , where the R's represent a radical (a portion of a complete molecule; not necessarily a free radical ) and O's are single oxygen atoms. Oxygen atoms are joined to each other and to adjacent elements through single covalent bonds , denoted by dashes or lines. The O−O group in a peroxide is often called the peroxide group, though some nomenclature discrepancies exist. This linkage is recognized as a common polyatomic ion , and exists in many molecules.
23-670: [REDACTED] Look up gsh in Wiktionary, the free dictionary. GSH may refer to: Glutathione , an important antioxidant George S. Halas , owner and coach of the Chicago Bears Goshen Municipal Airport (IATA code), Indiana, USA Global Scholars Hall , a building on the University of Oregon campus, Eugene, Oregon, USA Ghost Squad Hackers , hacktivist group Good Shepherd Homes ,
46-563: A British charity Gryazev-Shipunov (GSh), a weapons marque See also [ edit ] [REDACTED] Search for "gsh" or "g-s-h" on Misplaced Pages. GSHS (disambiguation) ГШ (disambiguation) (Russian: GSh ) All pages with titles containing GSH or GSHs All pages with titles containing g-s-h All pages with titles beginning with GSH All pages with titles beginning with Gsh All pages with titles beginning with G.S.H. GS (disambiguation) Topics referred to by
69-406: A potent reducing agent, donates electrons to disulfide bonds in the nanogels, initiating a thiol-disulfide exchange reaction. This reaction breaks the disulfide bonds, converting them into two thiol groups, and facilitates targeted drug release where it is needed most. This reaction is called a thiol-disulfide exchange reaction. where R and R' are parts of the micro-nanogel structure, and GSSG
92-494: Is a measure of cellular oxidative stress where increased GSSG-to-GSH ratio is indicative of greater oxidative stress. In the reduced state, the thiol group of cysteinyl residue is a source of one reducing equivalent . Glutathione disulfide (GSSG) is thereby generated. The oxidized state is converted to the reduced state by NADPH . This conversion is catalyzed by glutathione reductase : GSH protects cells by neutralising (reducing) reactive oxygen species . This conversion
115-588: Is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species , free radicals , peroxides , lipid peroxides , and heavy metals . It is a tripeptide with a gamma peptide linkage between the carboxyl group of the glutamate side chain and cysteine . The carboxyl group of the cysteine residue is attached by normal peptide linkage to glycine . Glutathione biosynthesis involves two adenosine triphosphate -dependent steps: While all animal cells are capable of synthesizing glutathione, glutathione synthesis in
138-412: Is different from Wikidata All article disambiguation pages All disambiguation pages Glutathione Glutathione ( GSH , / ˌ ɡ l uː t ə ˈ θ aɪ oʊ n / ) is an organic compound with the chemical formula HOCOCH(NH 2 )CH 2 CH 2 CONHCH(CH 2 SH)CONHCH 2 COOH . It is an antioxidant in plants , animals , fungi , and some bacteria and archaea . Glutathione
161-434: Is illustrated by the metabolism of N -acetyl- p -benzoquinone imine (NAPQI). NAPQI is a reactive metabolite formed by the action of cytochrome P450 on paracetamol (acetaminophen). Glutathione conjugates to NAPQI, and the resulting ensemble is excreted. In plants, glutathione is involved in stress management. It is a component of the glutathione-ascorbate cycle , a system that reduces poisonous hydrogen peroxide . It
184-412: Is illustrated by the reduction of peroxides: and with free radicals: Aside from deactivating radicals and reactive oxidants, glutathione participates in thiol protection and redox regulation of cellular thiol proteins under oxidative stress by protein S -glutathionylation, a redox-regulated post-translational thiol modification. The general reaction involves formation of an unsymmetrical disulfide from
207-419: Is in the mitochondria . Human beings synthesize glutathione, but a few eukaryotes do not, including some members of Fabaceae , Entamoeba , and Giardia . The only known archaea that make glutathione are halobacteria . Some bacteria , such as " Cyanobacteria " and Pseudomonadota , can biosynthesize glutathione. Systemic availability of orally consumed glutathione has poor bioavailability because
230-401: Is oxidized glutathione (glutathione disulfide). The breaking of disulfide bonds causes the nanogel to degrade into smaller fragments. This degradation process leads to the release of encapsulated drugs. The released drug molecules can then exert their therapeutic effects, such as inducing apoptosis in cancer cells. The content of glutathione in must , the first raw form of wine, determines
253-865: Is the precursor of phytochelatins , glutathione oligomers that chelate heavy metals such as cadmium . Glutathione is required for efficient defence against plant pathogens such as Pseudomonas syringae and Phytophthora brassicae . Adenylyl-sulfate reductase , an enzyme of the sulfur assimilation pathway, uses glutathione as an electron donor. Other enzymes using glutathione as a substrate are glutaredoxins . These small oxidoreductases are involved in flower development, salicylic acid , and plant defence signalling. Among various types of cancer , lung cancer , larynx cancer , mouth cancer , and breast cancer exhibit higher concentrations (10-40 mM) of GSH compared to healthy cells. Thus, drug delivery systems containing disulfide bonds , typically cross-linked micro-nanogels, stand out for their ability to degrade in
SECTION 10
#1732801251984276-426: The browning , or caramelizing effect, during the production of white wine by trapping the caffeoyltartaric acid quinones generated by enzymic oxidation as grape reaction product . Its concentration in wine can be determined by UPLC-MRM mass spectrometry. Peroxide The characteristic structure of any regular peroxide is the oxygen-oxygen covalent single bond, which connects the two main atoms together. In
299-413: The organelles . The concentration of glutathione in the cytoplasm is significantly higher (ranging from 0.5-10 mM) compared to extracellular fluids (2-20 μM), reaching levels up to 1000 times greater. In healthy cells and tissue, more than 90% of the total glutathione pool is in the reduced form (GSH), with the remainder in the disulfide form (GSSG). 80-85% of cellular GSH is in the cytosol and 10-15%
322-411: The event that the molecule has no chemical substituents , the peroxy group will have a [-2] net charge . Each oxygen atom has a charge of negative one, as 5 of its valence electrons remain in the outermost orbital shell whilst one is occupied in the covalent bond . Because of the nature of the covalent bond, this arrangement results in each atom having the equivalent of 7 valence electrons, reducing
345-451: The function of citrulline as part of the nitric oxide cycle. It is a cofactor and acts on glutathione peroxidase . Glutathione is used to produce S-sulfanylglutathione, which is part of hydrogen sulfide metabolism. Glutathione facilitates metabolism of xenobiotics . Glutathione S -transferase enzymes catalyze its conjugation to lipophilic xenobiotics, facilitating their excretion or further metabolism. The conjugation process
368-403: The hydrolysis of S - D -lactoylglutathione to glutathione and D -lactic acid . It maintains exogenous antioxidants such as vitamins C and E in their reduced (active) states. Among the many metabolic processes in which it participates, glutathione is required for the biosynthesis of leukotrienes and prostaglandins . It plays a role in the storage of cysteine. Glutathione enhances
391-405: The liver has been shown to be essential. GCLC knockout mice die within a month of birth due to the absence of hepatic GSH synthesis. The unusual gamma amide linkage in glutathione protects it from hydrolysis by peptidases. Glutathione is the most abundant non-protein thiol ( R−SH -containing compound) in animal cells, ranging from 0.5 to 10 mmol/L. It is present in the cytosol and
414-452: The oxygen molecules is known as a peroxy group (sometimes called peroxo group, peroxyl group, of peroxy linkage ). The nomenclature of the peroxy group is somewhat variable, and exists as an exception to the rules of naming polyatomic ions. This is due to the fact that when it was discovered, it was believed to be monatomic. The term was introduced by Thomas Thomson in 1804 for a compound combined with as much oxygen as possible, or
437-509: The oxygens and giving them a negative charge. This charge is affected by the addition of other elements, with the properties and structure changing depending on the added group(s). The most common peroxide is hydrogen peroxide ( H 2 O 2 ), colloquially known simply as "peroxide". It is marketed as solutions in water at various concentrations. Many organic peroxides are known as well. In addition to hydrogen peroxide, some other major classes of peroxides are: The linkage between
460-417: The presence of high concentrations of glutathione (GSH). This degradation process releases the drug payload specifically into cancerous or tumorous tissue, leveraging the significant difference in redox potential between the oxidizing extracellular environment and the reducing intracellular cytosol. When internalized by endocytosis , nanogels encounter high concentrations of GSH inside the cancer cell. GSH,
483-423: The protectable protein (RSH) and GSH: Glutathione is also employed for the detoxification of methylglyoxal and formaldehyde , toxic metabolites produced under oxidative stress. This detoxification reaction is carried out by the glyoxalase system . Glyoxalase I (EC 4.4.1.5) catalyzes the conversion of methylglyoxal and reduced glutathione to S - D -lactoylglutathione. Glyoxalase II (EC 3.1.2.6) catalyzes
SECTION 20
#1732801251984506-450: The same term [REDACTED] This disambiguation page lists articles associated with the title GSH . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=GSH&oldid=1255642298 " Category : Disambiguation pages Hidden categories: Articles containing Russian-language text Short description
529-429: The tripeptide is the substrate of proteases (peptidases) of the alimentary canal , and due to the absence of a specific carrier of glutathione at the level of cell membrane. The administration of N-acetylcysteine (NAC), a cysteine prodrug, helps replenish intracellular GSH levels. Glutathione exists in reduced (GSH) and oxidized ( GSSG ) states. The ratio of reduced glutathione to oxidized glutathione within cells
#983016