This is a working overview of glutathione, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-12-08 and is reviewed periodically as new material appears.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its glutamate-cysteine linkage uses the gamma-carboxyl group of glutamate, a feature that resists standard peptidases. The cysteine residue provides a thiol group, which gives the molecule its reducing character. In cells, glutathione is often the most abundant small-molecule thiol, with concentrations varying widely by tissue and compartment. It exists mainly in a reduced form called GSH, while oxidation produces a disulfide-linked dimer called GSSG.
Biosynthesis proceeds in two ATP-dependent steps. First, glutamate-cysteine ligase joins glutamate and cysteine. Second, glutathione synthetase adds glycine to the intermediate. The pathway is regulated by cysteine availability, enzyme expression, and feedback inhibition by glutathione itself. Liver tissue has a particularly high capacity for synthesis and export. Because the molecule is made inside cells, circulating glutathione reflects a balance of release, uptake, and breakdown rather than simple dietary supply.
Several analytical methods can quantify glutathione, including high-performance liquid chromatography (HPLC) with UV or fluorescence detection for separating GSH and GSSG. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers higher specificity and sensitivity, often detecting nanomolar concentrations. The enzymatic recycling assay, often called the Tietze method, measures total glutathione by coupling reduction of GSSG to a colorimetric or fluorometric readout. Capillary electrophoresis and electrochemical detection are also used in specialized laboratories. Each method has distinct advantages and limitations regarding throughput, cost, and susceptibility to interference.
Interpreting glutathione measurements requires attention to pre-analytical variables. The GSSG concentration in a sample can rise artificially during storage or processing, making the GSH/GSSG ratio unreliable if not controlled. Reference ranges vary by specimen type, assay, and population, so comparisons across studies are difficult. Plasma glutathione is low and sensitive to hemolysis, while whole blood reflects primarily erythrocyte content. Many studies measure total glutathione rather than the reduced and oxidized forms separately, which limits conclusions about redox status.
| Property | Value | Notes |
|---|---|---|
| Common name | Glutathione (reduced form) | Often abbreviated GSH |
| Chemical class | Tripeptide | Contains glutamate, cysteine, and glycine |
| Molecular formula | C10H17N3O6S | Refers to the reduced form |
| Molar mass | 307.32 g/mol | Calculated for C10H17N3O6S |
| Appearance | White to off-white powder | Typical laboratory-grade solid |
Synthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine. The first step is rate-limiting and is influenced by cysteine availability and feedback inhibition by GSH. Breakdown involves gamma-glutamyl transferase and subsequent peptidases, which release constituent amino acids for reuse. Because turnover differs among tissues, measurements from blood, plasma, and tissues are not directly interchangeable. Research continues to clarify how compartment-specific pools are regulated in health and disease.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It contains an unusual gamma-glutamyl bond between glutamate and cysteine, which resists cleavage by many peptidases. The reduced form, GSH, carries a thiol group on cysteine and is the dominant intracellular form in most cells. Its structure allows it to participate in redox reactions and to serve as a sulfur donor. The oxidized form, GSSG, consists of two GSH molecules joined by a disulfide bond.
In cells, glutathione helps maintain the reducing environment of the cytosol and supports enzymes that counteract reactive oxygen species. It acts as a cofactor for glutathione peroxidases, which reduce hydrogen peroxide and lipid peroxides, and for glutathione S-transferases, which conjugate electrophiles. The ratio of GSH to GSSG is often used as an indicator of oxidative stress, although the ratio can vary by compartment and cell type. Glutathione also stores cysteine, an amino acid that can be limiting for protein synthesis and antioxidant defense.
Synthesis occurs in two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine to complete the tripeptide. The pathway is feedback-inhibited by GSH and limited by cysteine availability, so cysteine supply often constrains production. Once formed, GSH participates in redox buffering, xenobiotic conjugation, and protein glutathionylation. Glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid peroxides, yielding GSSG, while glutathione reductase regenerates GSH using NADPH. Glutathione S-transferases conjugate electrophiles to GSH, supporting detoxification and excretion.
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.
==== Organisation ==== Birds have a very efficient system for diffusing oxygen into the blood; birds have a ten times greater surface area to gas exchange volume than mammals. As a result, birds have more blood in their capillaries per unit of volume of lung than a mammal. The arteries are composed of thick elastic muscles to withstand the pressure of the ventricular contractions, and become more rigid as they move away from the heart. Blood moves through the arteries, which undergo vasoconstriction, and into arterioles which act as a transportation system to distribute primarily oxygen as well as nutrients to all tissues of the body. As the arterioles move away from the heart and into individual organs and tissues they are further divided to increase surface area and slow blood flow. Blood travels through the arterioles and moves into the capillaries where gas exchange can occur. Capillaries are organised into capillary beds in tissues; it is here that blood exchanges oxygen for carbon dioxide waste. In the capillary beds, blood flow is slowed to allow maximum diffusion of oxygen into the tissues. Once the blood has become deoxygenated, it travels through venules then veins and back to the heart. Veins, unlike arteries, are thin and rigid as they do not need to withstand extreme pressure. As blood travels through the venules to the veins a funnelling occurs called vasodilation bringing blood back to the heart.
Railway transport in Malaysia is state-run, and spans some 2,783 kilometres (1,729 mi). As of 2016, Malaysia has the world's 26th-largest road network, with some 238,823 kilometres (148,398 mi) of roads. Malaysia's inland waterways are the world's 22nd-longest, and total 7,200 km (4,474 mi). Among Malaysia's 114 airports, the busiest one is Kuala Lumpur International Airport (KLIA), located in the Sepang District; it is also the 12th-busiest airport in Asia. Among the seven federal ports, the major one is Port Klang, which is the 13th-busiest container port. Malaysia's flag carrier is Malaysia Airlines, providing international and domestic air services. Malaysia's telecommunications network is second only to Singapore's in Southeast Asia, with 4.7 million fixed-line subscribers and more than 30 million cellular subscribers. There are 200 industrial parks along with specialised parks such as Technology Park Malaysia and Kulim Hi-Tech Park. Fresh water is available to over 95% of the population, with groundwater accounting for 90% of the freshwater resources. Although rural areas have been the focus of great development, they still lag behind areas such as the West Coast of Peninsular Malaysia. The telecommunication network, although strong in urban areas, is less available to the rural population. Malaysia's energy infrastructure sector is largely dominated by Tenaga Nasional, the largest electric utility company in Southeast Asia. Customers in Peninsular Malaysia are connected to electricity through the National Grid.
== Nomenclature == This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with a quinone or similar compound as acceptor. The systematic name of this enzyme class is 2-hydroxy-1,4-benzoquinone:NADH oxidoreductase. Other names in common use include hydroxybenzoquinone reductase, 1,2,4-trihydroxybenzene:NAD oxidoreductase, and NADH:2-hydroxy-1,4-benzoquinone oxidoreductase.
On 4 December 2024, the Lebanese Health Ministry reported that since 7 October 2023, Israeli attacks killed 4,047 people, including 316 children and 790 women, and injured 16,638 others. Among the dead were at least 41 Lebanese Army soldiers and more than 200 medics. Several UNIFIL workers and peacekeepers were injured in numerous attacks by both Israel and Lebanese militias. By 25 November 2025, the Lebanese Health Ministry reported that Israeli attacks during the ceasefire had killed 331 people and injured 945. The UN said that at least 127 fatalities were civilians. At the height of the conflict in October 2024, more than 1.2 million Lebanese were displaced, including between 200,000 and 300,000 who fled into Syria.
Sources: en.wikipedia.org
It is expected that improvement of experimental sensitivity will allow discovery of very mild radioactivity of some isotopes now considered stable. For example, in 2003 it was reported that bismuth-209 (the only primordial isotope of bismuth) is very mildly radioactive, with half-life (1.9 ± 0.2) × 1019 yr, confirming earlier theoretical predictions from nuclear physics that bismuth-209 would very slowly alpha decay. Isotopes that are theoretically believed to be unstable but have not been observed to decay are termed observationally stable. Currently there are 105 "stable" isotopes which are theoretically unstable, 40 of which have been observed in detail with no sign of decay, the lightest in any case being 36Ar. Many "stable" nuclides are metastable but have not been observed to decay, and are expected to undergo very rare kinds of radioactive decay, including double beta decay. 146 nuclides from 62 elements with atomic numbers from 1 (hydrogen) to 66 (dysprosium) except 43 (technetium), 61 (promethium), 62 (samarium), and 63 (europium) are theoretically stable to any kind of nuclear decay — except for the theoretical possibility of proton decay, which has never been observed despite extensive searches for it; and spontaneous fission (SF), which is theoretically possible for the nuclides with atomic mass numbers ≥ 93, that is all those with atomic numbers ≥ 41. Besides SF, other theoretical decay routes for heavier elements include:
==== Experimental analogues ==== Insulin tregopil is an experimental ultra-fast-acting insulin that is being developed by Biocon. Unlike other insulin analogues, it is designed to be taken orally. It has been modified with the covalent attachment of a methoxy-triethylene-glycol-propionyl moiety at Lys-β29-amino group of the B-chain. This modification, along with the use of sodium caprate as a permeation enhancer, allows insulin tregopil to be absorbed through the gastrointestinal tract. Another oral analogue called ORMD-0801 is, as of 2025, in development by Oramed Pharmaceuticals. Insulin efsitora alfa is an experimental insulin analogue developed by Eli Lilly for the treatment of diabetes. Its glycemic control and safety were found to be similar to insulin degludec in a phase II clinical trial. NNC2215 is a bioengineered glucose-sensitive insulin analogue developed by Novo Nordisk researchers. The drug is designed to adjust its activity based on blood glucose levels, reducing insulin sensitivity when glucose concentrations are low, thereby lowering the risk of hypoglycemia. It also provides more stable blood sugar control by responding dynamically to fluctuations in glucose levels. A study on NNC2215 was published in the journal Nature on 16 October 2024, describing its potential as a major advancement in diabetes treatment and the role of protein engineering in future medicine. The development of glucose-sensitive insulin has been an area of interest in diabetes research since 1979, aiming to address blood sugar fluctuations.
Assistant Secretary of State Daniel Fried said that he told Georgian foreign minister Eka Tkeshelashvili (who said that her country was obliged to defend people) on 7 August to maintain unilateral ceasefire and not to engage the enemy forces. An anonymous U.S. functionary said that the West had suspicions that Russian incursion into Georgia had been prepared in advance. According to the official, the West suspected that Russia intentionally provoked the hostilities by offensive against Georgian villages. The anonymous official compared the war to numerous "unpleasant precedents", such as Warsaw Pact invasion of Czechoslovakia and the Soviet–Afghan War.
=== Validation === Validation is intended to ensure a product, service, or system (or portion thereof, or set thereof) results in a product, service, or system (or portion thereof, or set thereof) that meets the operational needs of the user. For a new development flow or verification flow, validation procedures may involve modeling either flow and using simulations to predict faults or gaps that might lead to invalid or incomplete verification or development of a product, service, or system (or portion thereof, or set thereof). A set of validation requirements (as defined by the user), specifications, and regulations may then be used as a basis for qualifying a development flow or verification flow for a product, service, or system (or portion thereof, or set thereof). Additional validation procedures also include those that are designed specifically to ensure that modifications made to an existing qualified development flow or verification flow will have the effect of producing a product, service, or system (or portion thereof, or set thereof) that meets the initial design requirements, specifications, and regulations; these validations help to keep the flow qualified. It is a process of establishing evidence that provides a high degree of assurance that a product, service, or system accomplishes its intended requirements. This often involves acceptance of fitness for purpose with end users and other product stakeholders. This is often an external process.
=== Enzyme profiling === Identification of substrates for orphan enzymes Optimization of known enzyme substrates Elucidation of signal transduction pathways Detection of contaminating enzyme activities Consensus sequence and key residues determination Identifying sites for protein-protein interactions within a complex
Sources: en.wikipedia.org
Limited/selective fasciectomy removes the pathological tissue, and is a common approach. A 2015 Cochrane review reported that low-quality evidence suggested that fasciectomy may be more effective for people with advanced Dupuytren's contractures. During the procedure, the person is under regional or general anesthesia. A surgical tourniquet prevents blood flow to the limb. The skin is often opened with a zig-zag incision but straight incisions with or without Z-plasty are also described and may reduce damage to neurovascular bundles. All diseased cords and fascia are excised. The excision has to be very precise to spare the neurovascular bundles. Because not all the diseased tissue is visible macroscopically, complete excision is uncertain. A 20-year review of surgical complications associated with fasciectomy showed that major complications occurred in 15.7% of cases, including digital nerve injury (3.4%), digital artery injury (2%), infection (2.4%), hematoma (2.1%), and complex regional pain syndrome (5.5%), in addition to minor complications including painful flare reactions in 9.9% of cases and wound healing complications in 22.9% of cases. After the tissue is removed the incision is closed. In the case of a shortage of skin, the transverse part of the zig-zag incision is left open. Stitches are removed 10 days after surgery. After surgery, the hand is wrapped in a light compressive bandage for one week. Flexion and extension of the fingers can start as soon as the anaesthesia has resolved. It is common to experience tingling within the first week after surgery.
West Indian limes began to take over from lemons, when Spain's alliance with France against Britain in the Napoleonic Wars made the supply of Mediterranean lemons problematic, and because they were more easily obtained from Britain's Caribbean colonies and were believed to be more effective because they were more acidic. It was the acid, not the (then-unknown) Vitamin C that was believed to cure scurvy. The West Indian limes were significantly lower in Vitamin C than the previous lemons and further were not served fresh but rather as lime juice, which had been exposed to light and air, and piped through copper tubing, all of which significantly reduced the Vitamin C. A 1918 animal experiment using representative samples of the Navy and Merchant Marine's lime juice showed that it had virtually no antiscorbutic power at all. The belief that scurvy was fundamentally a nutritional deficiency, best treated by consumption of fresh food, particularly fresh citrus or fresh meat, was not universal in the 19th and early 20th centuries, and thus sailors and explorers continued to have scurvy into the 20th century. For example, the Belgian Antarctic Expedition of 1897–1899 became seriously affected by scurvy when its leader, Adrien de Gerlache, initially discouraged his men from eating penguin and seal meat. In the Royal Navy's Arctic expeditions in the mid-19th century, it was widely believed that scurvy was prevented by good hygiene on board ship, regular exercise, and maintaining crew morale, rather than by a diet of fresh food.
252Cf(11B,pxn)262−xNo (x=5?) This reaction was studied at the LBNL in 1961 as part of their search for element 103. They detected 8.2 MeV alpha particles with a half-life of 15 s. This activity was assigned to a Z=102 isotope. Later work suggests an assignment to 257No, resulting most likely from the p5n channel with the 252Cf component of the californium target.
==== Legal definitions ==== The International Organization for Standardization describes an AI system as a "an engineered system that generates outputs such as content, forecasts, recommendations, or decisions for a given set of human‑defined objectives, and can operate with varying levels of automation". The EU AI Act defines an AI system as "a machine-based system that is designed to operate with varying levels of autonomy and that may exhibit adaptiveness after deployment, and that, for explicit or implicit objectives, infers, from the input it receives, how to generate outputs such as predictions, content, recommendations, or decisions that can influence physical or virtual environments". In the United States, influential but non‑binding guidance such as the National Institute of Standards and Technology's AI Risk Management Framework describes an AI system as "an engineered or machine-based system that can, for a given set of objectives, generate outputs such as predictions, recommendations, or decisions influencing real or virtual environments. AI systems are designed to operate with varying levels of autonomy".
Sources: en.wikipedia.org
Glutathione is a sulfur-containing tripeptide made from glutamate, cysteine, and glycine. It is found in most cells and participates in redox balance and detoxification reactions.
No. It is a tripeptide assembled from three amino acids. The term amino acid applies to the individual building blocks, not to the assembled molecule.
It is present in many tissues, with especially high amounts in liver. Intracellular concentrations are generally much higher than those found in blood plasma.
Glutathione oxidizes quickly when cells are disrupted or when samples sit at room temperature. Rapid processing or immediate freezing minimizes the conversion of GSH to GSSG. This step helps ensure that the measured ratio reflects the original biological state.