GSH comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-10-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | Refers to the reduced form |
| Molar mass | 307.32 g/mol | Calculated for the neutral molecule |
| Appearance | White crystalline powder | Often hygroscopic; protect from moisture |
| Water solubility | Soluble in water | Reported values vary with purity and form |
| Alternative names | GSH, reduced glutathione | GSH specifies the thiol form |
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 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 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 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 supports several cellular processes beyond direct antioxidant action. It serves as a cofactor for glutathione peroxidase and glutathione S-transferase enzymes, which reduce peroxides and conjugate electrophiles, respectively. The molecule also acts as a reservoir of cysteine, an amino acid that can limit protein synthesis and redox signaling. In human nutrition, oral glutathione is sold as a supplement, but how much intact glutathione reaches tissues after ingestion remains an active research question. Clinical claims about supplementation are not uniformly supported by controlled trials.
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.
Levomethorphan (LVM) (INN, BAN) is an opioid analgesic of the morphinan family that has never been marketed. It is the L-stereoisomer of racemethorphan (methorphan). The effects of the two isomers of racemethorphan are quite different, with dextromethorphan (DXM) being an antitussive at low doses, but a dissociative at much higher doses. Levomethorphan is about five times stronger than morphine. Levomethorphan is a prodrug to levorphanol, analogously to DXM acting as a prodrug to dextrorphan, or codeine behaving as a prodrug to morphine. As such, levomethorphan has similar effects to levorphanol but is less potent as it must be demethylated to the active form by liver enzymes before being able to produce its effects. As a prodrug of levorphanol, levomethorphan functions as a potent agonist of all three of the opioid receptors, μ, κ (κ1 and κ3 but notably not κ2), and δ, as an NMDA receptor antagonist, and as a serotonin-norepinephrine reuptake inhibitor. Via activation of the κ-opioid receptor, levomethorphan can produce dysphoria and psychotomimetic effects such as dissociation and hallucinations. Levomethorphan is listed under the Single Convention on Narcotic Drugs 1961 and is regulated like morphine in most countries. In the United States it is a Schedule II Narcotic controlled substance with a DEA ACSCN of 9210 and a 2014 annual aggregate manufacturing quota of 195 grams, up from 6 grams the year before. The salts in use are the tartrate (free base conversion ratio 0.644) and hydrobromide (0.958).
=== Marketed === Daridorexant (nemorexant; Quviviq) – dual OX1 and OX2 antagonist – approved for insomnia in January 2022, formerly under development for sleep apnea – half-life 8 hours Fazamorexant (Mengping) – dual OX1 and OX2 antagonist – approved for insomnia in China in May 2026 – half-life 2–4 hours Lemborexant (Dayvigo) – dual OX1 and OX2 antagonist – approved for insomnia in December 2019 and released June 1 2020, under development for circadian rhythm sleep disorders, chronic obstructive pulmonary disease, and sleep apnea – half-life 17–55 hours Suvorexant (Belsomra) – dual OX1 and OX2 antagonist – approved for insomnia in August 2014, under development for delirium – half-life 12 hours Vornorexant (Vorzzz) – dual OX1 and OX2 antagonist – approved for insomnia in Japan in August 2025 – half-life 1.5–3 hours
Primary treatment for wastewater or drinking water includes settling in a sedimentation chamber to remove as much of the solid matter as possible before applying additional treatments. The amount removed is controlled by the hydraulic residence time (HRT). When water flows through a volume at a slower rate, less energy is available to keep solid particles entrained in the stream and there is more time for them to settle to the bottom. Typical HRTs for sedimentation basins are around two hours, although some groups recommend longer times to remove micropollutants such as pharmaceuticals and hormones. Disinfection is the last step in the tertiary treatment of wastewater or drinking water. The types of pathogens that occur in untreated water include those that are easily killed like bacteria and viruses, and those that are more robust such as protozoa and cysts. The disinfection chamber must have a long enough HRT to kill or deactivate all of them.
Steiner believed that nationalism is too inherently violent to satisfy the moral prerogative of Judaism, having said "that because of what we are, there are things we can't do " and has suggested that Nazism was Europe's revenge on the Jews for inventing conscience; father of David Steiner (academic); executive director of the Johns Hopkins Institute for Education Policy; appointed to the Practitioner Council at the Hoover Institute, Stanford University. Hillel Steiner (born 1942) is a prolific author, scholar, academic, editor and political philosopher and is Emeritus Professor of Political Philosophy at the University of Manchester; signatory to the Euston Manifesto and elected to the Fellowship of the British Academy in 1999. He is a member of the following organisations: American Philosophical Association, Aristotelian Society, International Association for the Philosophy of Law and Social Philosophy, Basic Income Earth Network. British Philosophical Association, European Society for the History of Economic Thought, Political Studies Association, Society for Applied Philosophy, and the September Group.
Sources: en.wikipedia.org
Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pressure of blood vessels ensures that this boiling point remains above the internal body temperature of 37 °C. Although the blood will not boil, the formation of gas bubbles in bodily fluids at reduced pressures, known as ebullism, is still a concern. The gas may bloat the body to twice its normal size and slow circulation, but tissues are elastic and porous enough to prevent rupture. Swelling and ebullism can be restrained by containment in a pressure suit. Shuttle astronauts wore a fitted elastic garment called the Crew Altitude Protection Suit (CAPS) which prevents ebullism at pressures as low as 2 kPa (15 Torr). Rapid boiling will cool the skin and create frost, particularly in the mouth, but this is not a significant hazard. Animal experiments show that rapid and complete recovery is normal for exposures shorter than 90 seconds, while longer full-body exposures are fatal and resuscitation has never been successful. A study by NASA on eight chimpanzees found all of them survived two and a half minute exposures to vacuum. There is only a limited amount of data available from human accidents, but it is consistent with animal data. Limbs may be exposed for much longer if breathing is not impaired.
==== Medieval photography ==== The art historian Nicholas Allen has proposed that the image on the shroud could have been formed as early as the 13th century using techniques described in the 1011 Book of Optics. However, according to Mike Ware, a chemist and expert on the history of photography, Allen's proposal "encounters serious obstacles with regard to the technical history of the lens. Such claimants tend to draw upon the wisdom of hindsight to project a distorted historical perspective, wherein their cases rest upon a particular concatenation of procedures which is exceedingly improbable; and their 'proofs' amount only to demonstrating (none too faithfully) that it was not totally impossible." Among other difficulties, Allen's hypothesized process would have required that the subject (a corpse) be exposed in the sunlight for months.
Vitamin B12, also known as cobalamin or extrinsic factor, is a water-soluble vitamin involved in metabolism. One of eight B vitamins, it serves as a vital cofactor in DNA synthesis and both fatty acid and amino acid metabolism. It plays an essential role in the nervous system by supporting myelin synthesis and is critical for the maturation of red blood cells in the bone marrow. Animals require B12 but plants do not, relying instead on alternative enzymatic pathways. Vitamin B12 is the most chemically complex of all vitamins, and is synthesized exclusively by certain archaea and bacteria. Natural food sources include meat, shellfish, liver, fish, poultry, eggs, and dairy products. It is also added to many breakfast cereals through food fortification and is available in dietary supplement and pharmaceutical forms. Supplements are commonly taken orally but may be administered via intramuscular injection to treat deficiencies. In healthy adults, vitamin B12 deficiency is not common, mainly because body stores of the vitamin are substantial and turnover is slow, with relatively low dietary requirements. However, B12 deficiency in the elderly is a significant concern, and is related to dementia. The most common cause in developed countries is impaired absorption due to loss of gastric intrinsic factor (IF), required for absorption. A related cause is reduced stomach acid production with age or from long-term use of proton-pump inhibitors, H2 blockers, or other antacids, and interaction with metformin.
UK academic and end-user community funded by UKRI: UK Metamaterials Network UK Government Rapid Technology Assessment looking at Metamaterials PwC Tech Translated: Metamaterials Centre for Metamaterial Research and Innovation, University of Exeter, UK www.metamaterials.center Institute of Physics, Impact Project Pathway "Commercialising Metamaterials"
=== 10 March === The SAF claimed to have destroyed 47 vehicles and 100 drones belonging to the RSF in El Fasher over the course of 10 days. They also claimed that local forces killed 15 fighters and that they recaptured the whole Al-Salam neighborhood and the Lafat Taqro buildings in the south of the city.
Sources: en.wikipedia.org
== Further reading == Kishi, K.; Okabe, K.; Shimizu, R.; Kubota, Y. (2012). "Fetal Skin Possesses the Ability to Regenerate Completely: Complete Regeneration of Skin". The Keio Journal of Medicine. 61 (4): 101–108. doi:10.2302/kjm.2011-0002-ir. PMID 23324304.
=== Tahini's === Tahini's is a fast-casual Mediterranean and Middle Eastern fusion restaurant chain founded in London, Ontario, in 2012 by Omar Hamam. The chain is known for blending traditional shawarma with international cuisine, featuring items such as butter chicken shawarma, Jamaican jerk shawarma, and shawarma ramen. As of 2026, Tahini's operates over 70 locations across Canada and has begun expanding into international markets including the United States.
The ice crystals that develop within frozen tofu (凍豆腐 dòngdòufu, 冰豆腐 bīngdòufu in Chinese, both meaning "frozen tofu") result in the formation of large cavities that appear to be layered. Frozen tofu takes on a yellowish hue in the freezing process. Frozen tofu originates in the Jiangnan region of China and is commonly made at home from soft tofu. It is also commercially sold as a specialty in Hong Kong, Taiwan, and other areas with Jiangnan emigrants. It is regularly paired with tatsoi as a winter dish. Frozen tofu is defrosted before serving and sometimes pressed to remove moisture prior to use. During freezing, the ice crystals puncture cell walls and facilitate the release of free and bound water and cause a decrease in total water content in tofu after freezing then thawing. The initial protein-water bonds are irreversibly replaced by protein-protein bonds, which are more elastic and cause a structural change to the gel network and lead to an increase in textural properties such as hardness, springiness, cohesiveness, and gumminess. In Japan, two kinds of freeze-dried tofu are produced. Those are usually rehydrated by being soaked in water prior to consumption. In their dehydrated state, they do not require refrigeration.
== Structure == PnuC of Salmonella typhimurium and Haemophilus influenzae are integral membrane proteins, 239 and 226 amino acyl residues (aas) in length, respectively, with 7 putative transmembrane α-helical segments. The structure of NadR has been determined. Mutations in the nadR gene which interfere with NR uptake occur in the C-terminal part of NadR. A helix-turn-helix DNA binding domain present in NadR of S. enterica serovar Typhimurium could not be found in the NadR homologue of H. influenzae. Therefore, it was proposed that in H. influenzae NadR has no regulatory function at the transcriptional level. The structures of the human NR kinase 1 (2QL6_P) with nucleotide and nucleoside substrates bound have been solved. It is structurally similar to Rossmann fold metabolite kinases. PnuC has been shown to resemble SWEET porters in overall fold, supporting the conclusion that these two families are members of the TOG superfamily.
zygonema Also zygotene stage. In meiosis, the second of five substages of prophase I, following leptonema and preceding pachynema. During zygonema, synapsis occurs, physically binding homologous chromosomes to each other, and the cell's centrosome divides into two daughter centrosomes, each containing a single centriole.
Sources: en.wikipedia.org
It is a tripeptide of glutamate, cysteine, and glycine. The glutamate-cysteine bond is unusual because it forms through the gamma-carboxyl group.
It reflects the balance between oxidant exposure and antioxidant capacity. The ratio is not a direct clinical diagnosis and depends on the tissue and sample method.
No. It also participates in detoxification, amino acid transport, and protein modification. Its roles vary by cell type and compartment.
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.