This is a working overview of thiol, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-06 and is reviewed periodically as new material appears.
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 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.
| 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 |
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.
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.
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.
=== Legal status === In the United States, benzodiazepines are Schedule IV drugs under the Federal Controlled Substances Act, even when not on the market (for example, flunitrazepam), with the exception of flualprazolam, etizolam, clonazolam, flubromazolam, and diclazepam which are placed in Schedule I. In Canada, possession of benzodiazepines is legal for personal use. All benzodiazepines are categorized as Schedule IV substances under the Controlled Drugs and Substances Act. In the United Kingdom, benzodiazepines are Class C controlled drugs, carrying the maximum penalty of 7 years imprisonment, an unlimited fine, or both for possession and a maximum penalty of 14 years imprisonment, an unlimited fine, or both for supplying benzodiazepines to others. In the Netherlands, since October 1993, benzodiazepines, including formulations containing less than 20 mg of temazepam, are all placed on List 2 of the Opium Law. A prescription is needed for possession of all benzodiazepines. Temazepam formulations containing 20 mg or greater of the drug are placed on List 1, thus requiring doctors to write prescriptions in the List 1 format. In East Asia and Southeast Asia, temazepam and nimetazepam are often heavily controlled and restricted. In certain countries, triazolam, flunitrazepam, flutoprazepam and midazolam are also restricted or controlled to certain degrees. In Hong Kong, all benzodiazepines are regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance. Previously only brotizolam, flunitrazepam and triazolam were classed as dangerous drugs.
== Side effects == Common adverse effects (occurring in between 1 and 10% of people) include low potassium, decreased appetite, delirium, headache, sleepiness, vein inflammation, difficulty breathing, acute respiratory failure, vomiting, diarrhea, nausea, stomach pain, elevated results in liver function tests, rash, itchy skin, kidney failure, chest pain, and fatigue. There are several uncommon side effects as well. In preclinical studies, isavuconazonium caused birth defects in animals; it has not been tested in pregnant women.
Water politics is politics affected by water and water resources. Water, particularly fresh water, is a strategic resource across the world and an important element in many political conflicts. It causes health impacts and damage to biodiversity. Access to safe drinking water has improved over the last decades in almost every part of the world, but approximately one billion people still lack access to safe water and over 2.5 billion lack access to adequate sanitation. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in some developing regions of the world, water demand will exceed supply by 50%. 1.6 billion people have gained access to a safe water source since 1990. The proportion of people in developing countries with access to safe water is calculated to have improved from 30% in 1970 to 71% in 1990, 79% in 2000, and 84% in 2004. A 2006 United Nations report stated that "there is enough water for everyone", but that access to it is hampered by mismanagement and corruption. In addition, global initiatives to improve the efficiency of aid delivery, such as the Paris Declaration on Aid Effectiveness, have not been taken up by water sector donors as effectively as they have in education and health, potentially leaving multiple donors working on overlapping projects and recipient governments without empowerment to act.
== External links == Diabetes in America, 2nd Edition (textbook) (PDFs) Archived 25 April 2011 at the Wayback Machine – National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) IDF Diabetes Atlas Type 1 Diabetes Archived 30 October 2009 at the Wayback Machine at the American Diabetes Association ADA's Standards of Medical Care in Diabetes 2019
Educating patients who have rheumatoid arthritis has shown a positive effect on how patients engage in their plan of care; the patient will be aware of fatigue, activity limitations, and pain and know possible side effects of how to manage this pain. Lack of knowledge can often lead to fear and limit adherence. Intervention by physical therapists plays a key role in offering proper tools for self-management, motivation in activities of daily living, and any assistive device use if needed. Patients will be assisted in managing neurological impairments and musculoskeletal stiffness to maximize strength and function. Encouraging patients to balance physical activity with their everyday living can prevent further joint damage and provide a sense of control. The use of extra-depth shoes and molded insoles may reduce pain during weight-bearing activities such as walking. Insoles may also prevent the progression of bunions.
Sources: en.wikipedia.org
=== Medicine === Melamine derivatives of arsenical drugs are potentially important in the treatment of African trypanosomiasis. Melamine use as non-protein nitrogen (NPN) for cattle was described in a 1958 patent. In 1978, however, a study concluded that melamine "may not be an acceptable non-protein N source for ruminants" because its hydrolysis in cattle is slower and less complete than other nitrogen sources such as cottonseed meal and urea.
Snakes commonly involved in envenomations include elapids (such as kraits, cobras and mambas), vipers, and sea snakes. The majority of snake species do not have venom and kill their prey by constriction (squeezing them). Venomous snakes can be found on every continent except Antarctica. Determining the type of snake that caused a bite is often not possible. The World Health Organization says snakebites are a "neglected public health issue in many tropical and subtropical countries", and in 2017, the WHO categorized snakebite envenomation as a Neglected Tropical Disease (Category A). The WHO also estimates that between 4.5 and 5.4 million people are bitten each year, and of those figures, 40–50% develop some kind of clinical illness as a result. Furthermore, the death toll from such an injury could range between 80,000 and 130,000 people per year. The purpose was to encourage research, expand the accessibility of antivenoms, and improve snakebite management in "developing countries". Prevention of snake bites can involve wearing protective footwear, avoiding areas where snakes live, and not handling snakes. Treatment partly depends on the type of snake. Washing the wound with soap and water and holding the limb still is recommended. Trying to suck out the venom, cutting the wound with a knife, or using a tourniquet is not recommended. Antivenom is effective at preventing death from bites; however, antivenoms frequently have side effects. The type of antivenom needed depends on the type of snake involved.
== International law == Trump's proposal for Gaza is against international law; the forcible transfer of populations is prohibited. Members of Trump's administration have walked back on elements of the plan on a few occasions, although in one subsequent statement, Trump held firm to his original plan. On 21 February 2025, after opposition from Arab states, Trump said he would "recommend" but not enforce his plan for the American takeover of Gaza and the re-settlement of the Palestinian population. Arab League leaders met in March to create a counter proposal to Trump's plan, which was rejected by the US and Israel due to concerns about the proposed governance of postwar Gaza and other issues. The White House released a statement that Trump stood by his vision of Gaza without Hamas and welcomed additional talks. In July, Netanyahu met with Trump and reiterated support for the plan of relocating Palestinians, saying it was "free choice" if Palestinians wanted to stay or leave. The US and Israel were working to identify cooperating countries for the plan.
=== "In the Hepatitis B Camp" === "In the Hepatitis B Camp" is a popular website for hepatitis B carriers' human rights in China. Its online forum is the world's biggest such forum with over 300,000 members. The website was first shut down by the Chinese government in November 2007. Lu Jun, the head of the rights group, managed to reopen the website by moving it to an overseas server, but the authorities in May 2008 began blocking access to the website within China, only 10 days after government officials participated in an event for World Hepatitis Day at the Great Wall of China. An official had told the head of the rights group, Lu Jun, at the time that the closure was due to the Beijing Olympic Games.
Sources: en.wikipedia.org
Analytical chemistry has applications across science and industry. It is fundamental to forensic science (e.g., DNA fingerprinting and toxicology), bioanalysis (e.g., measuring drug concentrations in pharmacokinetic studies), clinical analysis (e.g., blood glucose monitoring and COVID-19 PCR testing), environmental monitoring (e.g., testing for pollutants in water and air), and materials science (e.g., quality control of semiconductors and nanomaterials). Great effort is being put into shrinking the analysis techniques to chip size. Although few examples of such systems compete with traditional analysis techniques, potential advantages include size/portability, speed, and cost. Micro total analysis system (μTAS) or lab-on-a-chip. Microscale chemistry reduces the amount of chemicals used. Many developments improve the analysis of biological systems. Examples of rapidly expanding fields in this area are genomics, DNA sequencing and related research in genetic fingerprinting and DNA microarray; proteomics, the analysis of protein concentrations and modifications, especially in response to various stressors, at various developmental stages, or in various parts of the body; metabolomics, which deals with metabolites; transcriptomics, including mRNA and associated fields; lipidomics, dealing with lipids and its related fields; peptidomics, dealing with peptides and its related fields; and metallomics, dealing with metal concentrations and especially with their binding to proteins and other molecules.
During the early hours of 8 December 2024, Prime Minister Ghazi al-Jalali tried to reach Assad by phone, but no one responded. Meanwhile, the Syrian Observatory for Human Rights reported that Syrian government forces were disbanding after being informed by superiors that the regime had fallen following the departure of a private flight from an airport in Damascus. The capture of Homs that same morning by Tahrir al-Sham and the Syrian National Army effectively cut Damascus off from al-Assad's coastal strongholds of Tartus and Latakia. Some government members and al-Assad family members tried to escape the encirclement. Maher al-Assad successfully fled to Iraq via helicopter, but the car of Bashar's cousins Ihab Makhlouf and Iyad Makhlouf was intercepted by rebels who killed Ihab and captured Iyad. The head of the palace security was still at his post at Assad's residence, informing fleeing soldiers that he would not abandon the location without the president. Unwilling to believe that Bashar al-Assad had left him behind, he was eventually captured by insurgents. Within hours, all of Damascus was captured by the rebels, most of them belonging to the SOR. A group of opposition figures announced their victory over a Syrian state television broadcast. Simultaneously, Prime Minister Ghazi al-Jalali expressed his readiness to "extend its hand" to the opposition. The Syrian Army Command put two contradictory statements out: one of admission of defeat and a second to continue its fight against "terrorist groups", specifically in Homs, Hama and Daraa.
== As a drug target == With its integral role in HIV replication, HIV protease has been a prime target for drug therapy. HIV protease inhibitors work by specifically binding to the active site by mimicking the tetrahedral intermediate of its substrate and essentially becoming “stuck,” in the catalytic cycle, disabling the enzyme. After assembly and budding, viral particles lacking active protease cannot mature into infectious virions. Several protease inhibitors have been licensed for HIV therapy. There are ten HIV-1 PR inhibitors that are currently approved by the Food and Drug Administration: indinavir, saquinavir, ritonavir, nelfinavir, lopinavir, amprenavir, fosamprenevir, atazanavir, tipranavir, and darunavir. Many of the inhibitors have different molecular components and thus different mechanistic actions, such as blocking the active site. Their functional roles also extend to influencing circulation concentrations of other inhibitor drugs (ritonavir) and being used only for certain circumstances in which the virus exhibits tolerance of other inhibitors (tipranavir).
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.
It is a tripeptide of glutamate, cysteine, and glycine. The glutamate-cysteine bond is unusual because it forms through the gamma-carboxyl group.