The short version of reduced glutathione fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-08-18 and is reviewed periodically as new material appears.
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.
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.
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.
| 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 is a small tripeptide built from glutamic acid, cysteine, and glycine. Its peptide bond between glutamate and cysteine involves the gamma-carboxyl group rather than the usual alpha-carboxyl group. This structure gives the molecule a reactive thiol on the cysteine residue. The reduced form, often abbreviated GSH, is the predominant intracellular species in many cell types. Because the thiol can donate electrons, glutathione participates in redox chemistry and in the conjugation of reactive molecules.
Cells synthesize glutathione through two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine, and glutathione synthetase adds glycine to form the complete tripeptide. Breakdown occurs through gamma-glutamyl transpeptidase and subsequent peptidase reactions, forming the gamma-glutamyl cycle. Within cells, glutathione also forms a disulfide-linked dimer called GSSG when two GSH molecules react. The balance between GSH and GSSG is widely used as an indicator of oxidative conditions, although the ratio can vary by compartment and tissue.
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.
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 small tripeptide made of glutamic acid, cysteine, and glycine. Its cysteine thiol group allows reversible oxidation and reduction, making it central to cellular redox chemistry. The reduced form, often abbreviated GSH, predominates inside most cells, while the oxidized disulfide form, GSSG, forms when two GSH molecules react. The ratio of GSH to GSSG is widely used as an indicator of oxidative stress in laboratory research, though it does not by itself diagnose a clinical condition.
Biosynthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine, forming gamma-glutamylcysteine; glutathione synthetase then adds glycine to produce the complete tripeptide. Because the peptide bond from glutamate uses the gamma-carboxyl group, glutathione resists digestion by many ordinary peptidases. Tissues vary in synthesis capacity, and the liver generally contains high concentrations relative to many other organs. This uneven distribution contributes to organ-specific differences in redox buffering and affects how experimental results are interpreted across tissue types.
Glutathione participates in detoxification reactions, amino acid transport, and the maintenance of protein thiols. It serves as a cofactor for several enzymes, including glutathione peroxidases and glutathione S-transferases. In research literature, altered glutathione status appears in studies of aging, infection, metabolic stress, and environmental exposure. Whether low glutathione is a cause, consequence, or marker of such conditions often remains unresolved. Direct measurement in blood or tissue provides a snapshot, but results depend on sample handling, timing, and the method used.
Fentanyl is contributing to an epidemic of synthetic opioid drug overdose deaths in the United States. From 2011 to 2021, overdose deaths involving prescription opioid (natural and semi-synthetic opioids and methadone) per year remained stable, while synthetic opioid (primarily fentanyl) associated overdose deaths per year increased from 2,600 overdoses to 70,601. Fentanyl was involved in the most drug overdose deaths in the United States in 2018. The United States National Forensic Laboratory estimates fentanyl reports by federal, state, and local forensic laboratories increased from 4,697 reports in 2014 to 117,045 reports in 2020. Fentanyl is often mixed, cut, or ingested alongside other drugs, including cocaine and heroin. Fentanyl has been reported in pill form, including pills mimicking pharmaceutical drugs such as oxycodone. Mixing with other drugs or disguising as a pharmaceutical makes it difficult to determine the correct treatment in the case of an overdose, resulting in more deaths. Emerging adulterants have further complicated the evolving fentanyl supply. In an attempt to reduce the number of overdoses from taking other drugs mixed with fentanyl, drug testing kits, strips, and labs are available.
=== Isocyanide complexes === Isocyanides also form extensive families of complexes that are related to the metal carbonyls. Typical isocyanide ligands are methyl isocyanide and t-butyl isocyanide (Me3CNC). A special case is CF3NC, an unstable molecule that forms stable complexes whose behavior closely parallels that of the metal carbonyls.
Modified atmosphere/modified humidity (MA/MH) packaging is a technology used to preserve the quality of fresh produce so that it can be sold to markets far away from where it is grown, extend the marketing period, and to help suppliers reduce food waste within the cold chain. Commercial examples of MA/MH include sea freight of Galia and cantaloupe melons from Central and South America to Europe (a 21-day journey) and North America (a 7-day journey); transport of white asparagus from fields in Peru to markets in Western Europe (a 20-day journey by land and sea); and trucking of cherries from orchards in Turkey to supermarkets in the UK (a 7-day journey).
Sources: en.wikipedia.org
Photosynthesis is the synthesis of carbohydrates from sunlight and carbon dioxide (CO2). In plants, cyanobacteria and algae, oxygenic photosynthesis splits water, with oxygen produced as a waste product. This process uses the ATP and NADPH produced by the photosynthetic reaction centres, as described above, to convert CO2 into glycerate 3-phosphate, which can then be converted into glucose. This carbon-fixation reaction is carried out by the enzyme RuBisCO as part of the Calvin–Benson cycle. Three types of photosynthesis occur in plants, C3 carbon fixation, C4 carbon fixation and CAM photosynthesis. These differ by the route that carbon dioxide takes to the Calvin cycle, with C3 plants fixing CO2 directly, while C4 and CAM photosynthesis incorporate the CO2 into other compounds first, as adaptations to deal with intense sunlight and dry conditions. In photosynthetic prokaryotes the mechanisms of carbon fixation are more diverse. Here, carbon dioxide can be fixed by the Calvin–Benson cycle, a reversed citric acid cycle, or the carboxylation of acetyl-CoA. Prokaryotic chemoautotrophs also fix CO2 through the Calvin–Benson cycle, but use energy from inorganic compounds to drive the reaction.
==== Etifoxine ==== Etifoxine has similar anxiolytic effects as benzodiazepine drugs, but does not produce the same levels of sedation and ataxia. Further, etifoxine does not affect memory and vigilance, and does not induce rebound anxiety, drug dependence, or withdrawal symptoms.
== Pharmacology == The antibody component of inotuzumab ozogamicin binds to CD22 receptors, which are expressed mostly on B cells. The whole conjugate is then drawn into the cell, where the ozogamicin is cleaved from the antibody by the acidic environment of the lysosome. The ozogamicin eventually travels to the nucleus where it breaks up DNA, causing the cell to die.
Sources: en.wikipedia.org
As of 2012, the company had expanded across the U.S. states of Connecticut, Indiana, Kentucky, Maine, Massachusetts, Michigan, New York, Ohio, Pennsylvania, Rhode Island, and West Virginia. On January 7, 2014, Tim Hortons opened a kiosk in what is now the Desert Diamond Arena (where the Arizona Coyotes of the NHL used to play) in Glendale, the first Tim Hortons in Arizona. A flagship Tim Hortons location within the Buffalo area opened at the LECOM Harborcenter on October 29, 2014. In 2016, Tim Hortons expanded to Minnesota with a store inside Mall of America. However, this location is closed. In 2017, the chain announced an expansion to Northeast Ohio with 105 stores to come to the greater Cleveland area. The first of these opened in the Ellet neighborhood of Akron in July 2019. In 2020, Tim Hortons partnered with Bolla Market to open "15 to 20 over the next 12 to 18 months" across Long Island. The stores are located inside gas stations. In 2022, Tim Hortons announced a planned expansion into Georgia and Texas. Over the next five years, it plans to open over 20 new stores in the Atlanta and Columbus, Georgia, areas plus greater Houston, Texas, and Nashville, Tennessee. On December 22, 2024, Tim Hortons opened their first location in Austin, Texas. The "largest Tim Hortons in the United States", a restaurant offering 24 hour service, opened in Bryan, Texas, in December, 2025.
=== Alexandria Ship Project === In January 2016, a mid-18th century ship was discovered on the waterfront of Alexandria, Virginia. Conservation efforts include keeping the wood submerged and wet since the wooden frame was waterlogged. The conservation of this ship is ongoing. When the waterlogged wooden frame was originally removed from the archaeological site, the timber frames were stored in fresh water vats until June 2017. The framed structure was then packaged and sent to the Conservation Research Laboratory at Texas A&M University for conservation. Documentation and conservation included laser scanning, modeling, X-ray, and wood degradation analysis before the treatment using polyethylene glycol and vacuum freeze drying
The mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) also interacts with PKCε; phosphorylation of mitoK(ATP) following preconditioning stimuli potentiates channel opening. PKCε modulates the interaction between subunit Kir6.1 of mitoK(ATP) and connexin-43, whose interaction confers cardioprotection. Lastly, several mitochondrial metabolic targets of PKCε phosphorylation involved in cardioprotection following activation with εRACK have been identified, including mitochondrial respiratory complexes I, II and III, as well as proteins involved in glycolysis, lipid oxidation, ketone body metabolism and heat shock proteins. The role of PKCε acting in non-mitochondrial regions of cardiomyocytes is less well understood, though some studies have identified sarcomeric targets. PKCε translocation to sarcomeres and phosphorylation of cTnI and cMyBPC is involved in the κ-opioid- and α-adrenergic-dependent preconditioning that slows myosin cycling rate, thus protecting the contractile apparatus from damage. Activation of PKCε by εRACK prior to ischemia was also found to phosphorylate Ventricular myosin light chain-2, however the functional significance remains elusive. Actin-capping protein, CapZ appears to affect the localization of PKCε to Z-lines and modulates the cardiomyocyte response to ischemic injury. Cardioprotection in mice with reduction of CapZ showed enhancement in PKCε translocation to sarcomeres, thus suggesting that CapZ may compete with PKCε for the binding of RACK2.
=== Marriage === Seligman writes: "Unlike money, which has at most a small effect, marriage is robustly related to happiness... In my opinion, the jury is still out on what causes the proven fact married people are happier than unmarried people." (pp. 55–56). Married persons report higher levels of happiness and well-being than single people. Other data has shown a spouse's happiness depends on the happiness of their partner. When asked, spouses reported similar happiness levels to each other. The data also shows the spouses' happiness level fluctuates similarly to one another. If the husband is having a bad week, the wife will similarly report she had a bad week. There is little data on alternatives like polyamory, although one study stated wife order in polygyny did not have a substantial effect on life or marital satisfaction over all. This study also found younger wives were happier than older wives. On the other hand, at least one large study in Germany found no difference in happiness between married and unmarried people. Studies have shown that married couples are consistently happier and more satisfied with their life than those who are single. Some research findings have indicated that marriage is the only real significant bottom-up predictor of life satisfaction for men and women, and that those people who have a higher life satisfaction prior to marriage, tend to have a happier marriage. Self-reported satisfaction typically drops as the years of marriage roll on, particularly for couples who have children compared to those who do not.
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.
It is a tripeptide of glutamate, cysteine, and glycine. The glutamate-cysteine bond is unusual because it forms through the gamma-carboxyl group.