thiol group raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
Quality control for glutathione materials checks identity, assay, purity, water content, and disulfide content. Commercial products vary from research-grade powder to dietary supplements, and labels may not distinguish reduced from oxidized forms. In the United States, oral glutathione is commonly sold as a dietary supplement rather than an approved drug, while injectable forms fall under different rules and may require a prescription. Regulatory status differs by country. Analytical certificates, when available, help verify what a material contains, but independent testing remains important for interpretation.
Laboratory measurement of glutathione typically starts with rapid acid extraction to prevent oxidation and enzymatic degradation. Common methods include enzymatic recycling assays, high-performance liquid chromatography, and liquid chromatography coupled with mass spectrometry. The recycling assay uses glutathione reductase and a thiol-reactive colorimetric or fluorescent reagent, measuring total glutathione after converting disulfide forms. Chromatographic methods can separate reduced and oxidized forms, which helps when the redox ratio is the target. Choice of method affects sensitivity, specificity, and the amount of sample needed.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | Reduced glutathione (GSH) |
| Molar mass | 307.32 g/mol | Calculated for C10H17N3O6S |
| Appearance | White to off-white powder | Typical solid form |
| Solubility | Water-soluble | Polar tripeptide |
| Common synonyms | GSH; L-glutathione | Gamma-glutamylcysteinylglycine |
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. 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.
Glutathione is a small sulfur-containing peptide built from glutamic acid, cysteine, and glycine. Its distinctive feature is a gamma-glutamyl bond between glutamate's side-chain carboxyl group and cysteine's amino group. This linkage resists ordinary peptidases and helps the molecule remain stable inside cells. The reduced thiol form, often abbreviated GSH, is the dominant intracellular species. The oxidized disulfide dimer, GSSG, forms when two reduced molecules link through their cysteine sulfur atoms. The balance between these forms is a common redox indicator.
In living systems, glutathione occurs in millimolar concentrations in many cell types, while extracellular levels are generally much lower. The liver holds a substantial share of the body's total pool, and the molecule participates in reduction, detoxification, and amino acid transport. It also serves as a cofactor for enzymes such as glutathione peroxidase and glutathione S-transferase. Because the cysteine residue supplies a reactive thiol, glutathione can donate electrons and become oxidized. Cells regenerate reduced glutathione through glutathione reductase using NADPH.
In England, an estimated 2,189,300 people were thought to have tested positive for COVID-19. 14 January Four women and two children are injured in a drive-by mass shooting close to a Catholic church in Euston Road, Euston, Central London. A 22-year-old man is arrested two days later on suspicion of attempted murder. Amid recent heavy rain, more than 100 flood warnings by the Environment Agency remain in place across the country, with hundreds of homes damaged and many left without power. Rishi Sunak confirms that the UK will send 14 Challenger 2 tanks to Ukraine to boost its war effort. 16 January Serving Metropolitan Police officer David Carrick admits over 40 offences including more than 20 rapes against 12 women over two decades. The National Education Union announces that teachers in England and Wales will strike on seven dates during February and March after members voted in favour of strike action. National strikes will be held on 1 and 15 February, and 15 March, as well as four days of regional strikes. The UK government announces it will block the Gender Recognition Reform (Scotland) Bill, the first time that the UK government has used powers to block a Scottish law. UK ministers say the draft law would "conflict with equality protections applying across Great Britain". The Royal College of Nursing announces a further two nurses' strikes for 6 and 7 February, described as the biggest so far. MPs vote 309–249 in favour of the Strikes (Minimum Service Levels) Bill 2023, which now moves to the committee stage.
In the context of the fall of communism throughout Eastern Europe during the revolutions of 1989, a protest in support of Reformed pastor László Tőkés that began in December 1989 in Timișoara quickly escalated into a national uprising against the communist regime, ultimately resulting in the execution of Ceaușescu and his wife Elena on 25 December 1989. An interim council composed of figures from civil society and former communist officials assumed control of the government, and Ion Iliescu became the provisional president of the country. The new government reversed many of the authoritarian communist policies and dismissed several leaders of the former regime, although still influenced by members of the former regime (the basis for the Golaniad, and Mineriads). In May 1990, the first free elections in Romania since the 1937 elections were held, with Iliescu of the National Salvation Front winning the presidency with 85% of the vote. In 1992, he was reelected in the first election after the adoption of a permanent constitution via a referendum held the previous year. Illiescu lost the 1996 election to Emil Constantinescu, but returned to power in 2000. Traian Băsescu was elected president in 2004 and 2009, serving until 2014 at which point Klaus Iohannis succeeded him, being re-elected in 2019 and serving until 2025. During these years several events occurred. In 2009, the country was bailed out by the International Monetary Fund as result of the Great Recession in Europe following the 2008 financial crisis.
== Africa == In countries such as Kenya, Lesotho, Mauritius, Nigeria, South Africa, Zambia, and Zimbabwe centenarians are often celebrated upon reaching their 100th Birthday by the locals and government. Former Senegalese President, Abdoulaye Wade, turned 100 on 29 May 2026, becoming the first state leader in West African history to become a centenarian.
Sloth World: An Online Sloth Bibliography Picture and information about a ground sloth skeleton on display at the University of Georgia's Science Library Academy of Natural Sciences ground sloth page Illinois State Museum ground sloth page Ground sloths at La Brea Eremotherium in Florida Have some ground sloths survived in Argentina? Ground sloths in general Western Center for Archaeology and Paleontology Hemet, CA
On 16 November, Hezbollah conducted eight anti-tank missiles targeting Israeli forces and military infrastructure. In the afternoon, Hezbollah attacked numerous towns near the border and targeted military gatherings in Shtula and Hadab Yaron. The IDF responded heavily in southern Lebanon and Israeli warplanes raided Hezbollah targets. Hezbollah announced that two of its members were killed. Four days later, the IDF base of Biranit suffered heavy damage from a Hezbollah barrage using Burkan rockets. IDF fighter jets struck numerous Hezbollah military targets, and soldiers struck a militant cell near Metula. The historically significant St. George church was heavily damaged in Yaroun after it was shelled by the IDF. The house of Amal Movement MP Kabalan Kabalan was also hit with rocket fire. Hezbollah claimed an attack on the IDF's 91st Division barracks at Baranit. On 21 November, an IDF airstrike in Kafr Kila killed an elderly woman and injured her granddaughter. Another team of journalists were targeted in an IDF strike near Tayr Harfa which killed three people, including two Al Mayadeen journalists, a reporter and a photojournalist, and a guide. On the same day, four members of the Al-Qassam Brigades were killed after an IDF strike on a car near Chaaitiyeh. A Hezbollah member was also killed in a separate attack in Khiam. Hezbollah told Al Jazeera that it would "respect" the temporary ceasefire deal between Israel and Hamas reached on 24 November 2023.
Sources: en.wikipedia.org
The mean lifetime of 238U (or any nuclide) is the half-life divided by ln(2) ≈ 0.693 (or multiplied by 1/ln(2) ≈ 1.443), which is about 2×1017 seconds, so 1 mole of 238U emits 3×106 alpha particles per second, producing the same number of thorium-234 atoms. In a closed system an equilibrium would be reached in which all members except the stable end-product have fixed ratios to one another, but in slowly decreasing amount. The amount of 206Pb will increase accordingly while that of 238U decreases; all steps in the decay chain have this same rate of 3×106 decayed particles per second per mole 238U. While 238U is minimally radioactive, its decay products, thorium-234 and protactinium-234, are beta particle emitters with half-lives of about 20 days and one minute respectively. Protactinium-234 decays to uranium-234, which has a half-life of hundreds of millennia, and this isotope does not reach an equilibrium concentration for a very long time. When the two first isotopes in the decay chain reach their relatively small equilibrium concentrations, a sample of initially pure 238U will emit three times the radiation due to 238U itself, and most of this radiation is beta particles. As already touched upon above, when starting with pure 238U, within a human timescale the equilibrium applies for the first three steps in the decay chain only. Thus, for one mole of 238U, 3×106 times per second one alpha and two beta particles and a gamma ray are produced, together 6.7 MeV, for a rate of 3 μW.
==== Sen-chan ==== Senichi Enari (江成 仙一, Enari Sen'ichi), also known as "Sen-chan" (センちゃん), is the eccentric, yet calmest and smartest member, of the team, due in part to his ability to think things through and being able to do his best thinking while in a handstand, which he considers his "thinking pose". Sen-chan serves as Deka Green (デカグリーン, Deka Gurīn). The oldest of seven siblings from a poor family, he displays nycto- and claustrophobia after accidentally falling into a well when he was a child. He was subsequently rescued by a policeman, which inspired him to take up police work. Despite his usually calm demeanor, he is said to be scary when angered. He also displays a crush on his teammate Umeko, but avoids showing it publicly. As of the crossover film Mahō Sentai Magiranger vs. Dekaranger, they have moved in together. As Deka Green, Sen-chan wields the D-Knuckle and D-Rod, which can combine to form the D-Blaster (ディーブラスター, Dī Burasutā) rifle. He also shares riding the Machine Bull (マシンブル, Mashin Buru) police car with Umeko. Using the D-Rod, Sen-chan can perform the Green Crash (グリーンクラッシュ, Gurīn Kurasshu) attack. Sen-chan is portrayed by Yousuke Itou (伊藤 陽佑, Itō Yōsuke). As a child, he is portrayed by Kengo Tajima (田島 健吾, Tajima Kengo).
In 2009, 86% of cadmium was used in batteries, predominantly in rechargeable nickel–cadmium batteries. Nickel–cadmium cells have a nominal cell potential of 1.2 V. The cell consists of a positive nickel hydroxide electrode and a negative cadmium electrode plate separated by an alkaline electrolyte (potassium hydroxide). The European Union put a limit on cadmium in electronics in 2004 of 0.01%, with some exceptions, and in 2006 reduced the limit on cadmium content to 0.002%. Another type of battery based on cadmium is the silver–cadmium battery.
This is an option only when the cancer is superficial and infects only the bottom third of the ureter. The procedure entails removing the segment of cancerous ureter and reattaching the end. Patients with advanced bladder cancer or disease, also often look to bladder reconstruction as a treatment. Current methods of bladder reconstruction include the use of gastrointestinal tissue. However, while this method is effective in improving the function of the bladder, it can actually increases the risk of cancer, and can cause other complications, such as infections, urinary stones, and electrolyte imbalance. Therefore, other methods loom in the future. For example, current research paves the way for use of pluripotent stem cells to derive urothelium, as they are highly and indefinitely proliferative in vitro (i.e. outside of the body).
Sources: en.wikipedia.org
Glutathione is built from three amino acids: glutamate, cysteine, and glycine. The linkage involves the gamma-carboxyl group of glutamate rather than the alpha-carboxyl group, which is unusual for peptides. This structure protects the bond from some common peptidases.
It is present in nearly all cells, with notable amounts in the liver, kidneys, and red blood cells. The highest intracellular concentrations are usually in the millimolar range. Levels differ by tissue, age, and physiological state.
It is not classified as an essential nutrient because cells can synthesize it from amino acids. Dietary sources exist, but their contribution to tissue pools is not fully established. The body's production depends on enzyme activity and precursor availability.
Common approaches include enzymatic recycling assays, HPLC, and LC-MS/MS. Acid extraction and rapid processing limit oxidation before analysis.