A practical reference on glutathione: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-08-12. Anything still debated is marked as such rather than presented as settled.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It occurs in nearly all living cells, with highest concentrations in liver, kidney, and red blood cells, and exists in reduced (GSH) and oxidized disulfide (GSSG) forms. The cysteine thiol group enables reversible oxidation and reduction reactions. This property makes glutathione a central participant in cellular redox balance. The balance between these forms is often used as an indicator of oxidative stress.
Glutathione synthesis proceeds in two ATP-dependent steps catalyzed by glutamate-cysteine ligase and glutathione synthetase. The first step joins glutamate and cysteine to form gamma-glutamylcysteine and is generally rate-limiting. The second step adds glycine to complete the tripeptide. Cysteine availability, feedback inhibition by glutathione, and oxidative conditions influence flux through this pathway. The pathway is conserved across many organisms, and degradation by gamma-glutamyl transpeptidase and related peptidases recycles amino acids for new synthesis.
Within cells, glutathione serves as a cofactor for glutathione peroxidases and glutathione S-transferases. These enzymes reduce hydrogen peroxide and organic peroxides or conjugate electrophilic compounds to the thiol group. The resulting conjugates can be exported and processed through mercapturic acid pathways. Glutathione also contributes to protein thiol homeostasis and to recycling of other antioxidants such as ascorbate. Its precise roles vary by tissue, and many regulatory effects observed in laboratory systems remain difficult to quantify in whole organisms.
In cells, glutathione exists mainly in a reduced form called GSH. When two GSH molecules react, they form oxidized glutathione, or GSSG, which contains a disulfide bond. The ratio of GSH to GSSG is often used as an indicator of oxidative stress. Enzymes such as glutathione peroxidase and glutathione reductase help cycle the molecule between these two states. This cycling supports antioxidant defense, detoxification of reactive molecules, and regulation of certain signaling pathways.
Glutathione is present in most tissues, with especially high concentrations in the liver. It also serves as a cofactor for some enzymes and helps transport amino acids across cell membranes. In plants and microorganisms, glutathione contributes to stress responses and metal handling. The molecule is synthesized in two ATP-dependent steps, first producing gamma-glutamylcysteine and then adding glycine. Because cysteine availability often limits synthesis, dietary and metabolic factors can influence glutathione levels. Research continues to examine how these levels relate to health and disease.
| Property | Value | Notes |
|---|---|---|
| Common name | Glutathione | Reduced form is abbreviated GSH |
| Chemical class | Tripeptide | Composed of glutamate, cysteine, and glycine |
| Molar mass | 307.32 g/mol | For reduced glutathione |
| CAS Registry Number | 70-18-8 | For reduced L-glutathione |
| Appearance | White crystalline powder | Typical solid reference material |
Glutathione functions in redox balance, detoxification, and sulfur amino acid storage. It participates in reactions that help maintain ascorbate and protein thiol status. The molecule serves as a cofactor for several enzymes, including glutathione peroxidases and glutathione S-transferases. These enzymes reduce peroxides and conjugate electrophiles, respectively. Glutathione also contributes to the metabolism of xenobiotics and to the transport of cysteine between tissues. How interorgan transport and tissue-specific regulation shape whole-body pools remains an active area of study.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its cysteine residue carries a thiol group, which allows the molecule to participate in reduction and oxidation reactions. The compound exists in most living cells, where the reduced form, often abbreviated GSH, is usually more abundant than the oxidized disulfide form, GSSG. Intracellular concentrations are commonly in the millimolar range, while extracellular concentrations are much lower. This uneven distribution supports its role as a major cellular redox buffer.
Cells synthesize glutathione through two ATP-dependent enzymatic steps. The first step combines glutamate and cysteine to form gamma-glutamylcysteine, catalyzed by glutamate-cysteine ligase. The second step adds glycine, producing the complete tripeptide, catalyzed by glutathione synthetase. Glutathione itself can inhibit the first enzyme, providing negative feedback when levels are high. Because cysteine is often limiting, its availability influences how quickly the pathway proceeds. These reactions occur in the cytosol, and the resulting glutathione can be distributed to other compartments.
Because GSH is central to redox balance, its status is studied in aging, liver disease, neurodegenerative conditions, and metabolic disorders. Observational studies often report lower GSH or higher GSSG in affected tissues, but such associations do not establish that raising glutathione changes disease outcomes. Oral glutathione is digested into amino acids, and whether intact absorption occurs remains debated; precursors such as N-acetylcysteine and cysteine donors are also investigated. Regulatory agencies generally treat glutathione as a dietary supplement, not an approved drug, and clinical claims require evidence from controlled trials.
Glutathione is a small tripeptide composed of glutamate, cysteine, and glycine, with the unusual gamma-glutamyl linkage between glutamate and cysteine. Its cysteine thiol group makes it a major non-enzymatic antioxidant in cells. The reduced form, GSH, predominates in most intracellular compartments, while the oxidized disulfide form, GSSG, is produced when GSH reduces reactive oxygen species. Intracellular concentrations often reach millimolar levels, whereas plasma concentrations are much lower, typically in the low micromolar range. This gradient reflects active synthesis, transport, and consumption rather than passive distribution.
In its reduced form, glutathione carries a sulfhydryl group that can donate electrons. This property lets it act as a major cellular antioxidant and redox buffer. Glutathione peroxidase uses it to reduce hydrogen peroxide and lipid peroxides, while glutathione reductase regenerates the reduced form using NADPH. The ratio of reduced glutathione to glutathione disulfide is widely used as an indicator of oxidative stress, though the ratio changes with compartment, cell type, and sample handling. Oxidized glutathione can also form mixed disulfides with proteins, affecting their activity.
Glutathione supports detoxification by conjugating reactive electrophiles through glutathione S-transferases. The resulting conjugates are processed and exported, often after further metabolism. It also stores cysteine, transports amino acids across membranes through the gamma-glutamyl cycle, and assists in the maturation of iron-sulfur clusters and some prostaglandins. In plants, animals, and many microbes, the molecule appears in similar roles, but concentrations vary enormously between tissues. Liver, kidney, and red blood cells tend to contain high amounts, while blood plasma contains much less.
Glutathione is a small tripeptide built from glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group, a linkage that resists ordinary peptidases. Cells make it in two ATP-dependent steps: gamma-glutamylcysteine synthetase joins glutamate and cysteine, then glutathione synthetase adds glycine. The pathway is feedback-inhibited by glutathione itself, so intracellular levels tend to stay within a narrow range. Because cysteine is often limiting, sulfur amino acid supply influences how much glutathione a cell can produce.
Slavery in Brazil began long before the first Portuguese settlement was established in 1532, as members of one tribe would enslave captured members of another. Later, Portuguese colonists were heavily dependent on indigenous labour during the initial phases of settlement to maintain the subsistence economy, and natives were often captured by expeditions called bandeiras. The importation of African slaves began midway through the 16th century, but the enslavement of indigenous peoples continued well into the 17th and 18th centuries. During the Atlantic slave trade era, Brazil imported more African slaves than any other country. Nearly 5 million slaves were brought from Africa to Brazil during the period from 1501 to 1866. Until the early 1850s, most African slaves who arrived on Brazilian shores were forced to embark at West Central African ports, especially in Luanda (in present-day Angola). Today, with the exception of Nigeria, the country with the largest population of people of African descent is Brazil. Slave labour was the driving force behind the growth of the sugar economy in Brazil, and sugar was the primary export of the colony from 1600 to 1650. Gold and diamond deposits were discovered in Brazil in 1690, which sparked an increase in the importation of African slaves to power this newly profitable market. Transportation systems were developed for the mining infrastructure, and population boomed from immigrants seeking to take part in gold and diamond mining.
== Horrevoets Trophy == In May 2009, The Ocean Race launched the Hans Horrevoets Rookie Award to recognize the outstanding under-30 sailor in each edition of the race as nominated by the respective skippers. Recipients:
== Flow control == There are various ways to control the fluid flow in the channels. They include changing the channel width and length, altering the wettability of the paper, diverting some fluid through a parallel channel, or changing the viscosity of the fluid. The flow in PADs can be turned off with dissolvable sugar bridges, Corona discharge treatment to alter a coating on the paper from a hydrophobic to hydrophilic state, or the use of an expandable polymer triggered by the flow to close the flow path.
Michael Howard Wigler (born September 3, 1947, in New York) is an American molecular biologist who has directed a laboratory at Cold Spring Harbor Laboratory since 1978 and is a member of the National Academy of Sciences. He is best known for developing methods to genetically engineer animal cells and his contributions to cancer, genomics and autism genetics.
Sources: en.wikipedia.org
For services to Business and to the UK Film Industry. Catherine Anne Goodman, LVO. Artist and Educator. For services to Art. Professor Roger James Goodman. Nissan Professor of Modern Japanese Studies and Warden, St. Antony's College, University of Oxford. For services to Social Science. Gayle Jean Margaret Gorman. Lately HM Chief Inspector and Chief Executive, Education Scotland. For services to Education and Charity. Gerard Arthur Georges Grech. Founder, Tech Nation and Managing Director, Founders at the University of Cambridge. For services to the Technology Sector. The Reverend Nicholas Glyn Paul Gumbel. Lately Vicar, Holy Trinity Brompton, London. For services to the Church of England. Paul Harris. Deputy Chief Executive Officer and Operations Director, HM Courts and Tribunals Service. For Public and Voluntary Service. Martin James Hewitt, QPM. Lately Chair, National Police Chiefs Council. For services to Policing. Professor Peter Michael Hollingsworth. Director of Science and Deputy Keeper, Royal Botanic Garden, Edinburgh. For services to Botanical Science. Karl James Hoods. Chief Digital and Information Officer, Department for Science, Innovation and Technology and Department for Energy Security and Net Zero. For services to Technology and to Education. Professor Andrew Lee Hopkins, FRS, FMedSci, FRSE. Chief Executive Officer, Exscientia. For services to Science and to Innovation. Christian Edward Johnston Horner, OBE. Team Principal and Chief Executive Officer, Red Bull Racing. For services to Motor Sport. Pauline Jean Howie, OBE.
In 1994, HCFA stated that in vitro fertilization was categorized as a therapeutic procedure, not a diagnostic procedure, and therefore not covered under CLIA. As such, AAB/ABB took the position that IVF laboratory tests are covered under CLIA, while ASRM and SART took the opposing position. On September 16, 1998, the Clinical Laboratory Improvement Advisory Committee (CLIAC) made a non-binding recommendation that CLIA coverage apply to embryology laboratories and suggested the College of American Pathologists (CAP) and ASRM accreditation checklist. However, the United States Secretary of Health and Human Services Donna Shalala did not implement the recommendation prompting the AAB to sue HHS to force a decision on March 16, 1999. In response, ASRM filed an amicus brief opposing AAB's lawsuit. On March 8, 2000, the lawsuit was dismissed by Thomas F. Hogan due to lack of standing. In 1994, the American Board of Bioanalysis (ABB) created the first CLIA-approved HCLD board exam for andrologists and embryologists.
== History == Pindolol was patented by Sandoz in 1969 and was launched in the US in 1977. Towards end of February 2020 FDA added this product to their "DRUG SHORTAGE" list stating this is due to "Shortage of an active ingredient" and this is likely to be related to Coronavirus outbreak and related supply chain impacts.
Dickeya dadantii is a Gram-negative bacillus that belongs to the family Pectobacteriaceae. It was formerly known as Erwinia chrysanthemi but was reassigned as Dickeya dadantii in 2005. Members of this family are facultative anaerobes, able to ferment sugars to lactic acid, have nitrate reductase, but lack oxidases. Even though many clinical pathogens are part of the order Enterobacterales, most members of this family are plant pathogens. D. dadantii is a motile, non-sporing, straight rod-shaped cell with rounded ends, much like the other members of the genus, Dickeya. Cells range in size from 0.8 to 3.2 μm by 0.5 to 0.8 μm and are surrounded by numerous flagella (peritrichous). In the natural plant environment, D. dadantii causes plant maladies such as necrosis, blight and "soft rot", which is a progressive tissue maceration. D. dadantii contains many pectinases that are able to macerate and break down the plant cell wall material. This exposed part of the plant releases nutrients that can facilitate bacterial growth. Commonly infected plants include potato tubers, bulbs of vegetables, and ornamental crops.
The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 29–117 mg per cup), with a median cup size of 225 ml (range 170–285 mL) and a caffeine concentration of 328 μg/mL (range 102–559 μg/mL). In comparison, drip or filter coffee was estimated to have a median caffeine content of 112 mg, with a median concentration of 621 μg/mL for the same cup size. Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.
Sources: en.wikipedia.org
GSH is the reduced thiol form, while GSSG is the disulfide-linked oxidized dimer. The GSH:GSSG ratio is used as a redox indicator, though the ratio can vary with sample handling and cell type.
Glutathione is present in many foods, including meats, poultry, fish, some vegetables, and fruits. Cooking, storage, and digestion affect the amounts available for absorption.
Yes, both enzymatic steps in glutathione synthesis consume ATP. The first step, catalyzed by glutamate-cysteine ligase, is usually rate-limiting.
Glutathione is a tripeptide made from glutamate, cysteine, and glycine. Its cysteine residue provides a thiol group that is central to its redox activity. The glutamate-cysteine bond forms through the gamma-carboxyl group of glutamate.