Everything below concerns glutathione. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
Glutathione is synthesized in two ATP-dependent steps. First, gamma-glutamylcysteine synthetase links glutamate and cysteine; second, glutathione synthetase adds glycine to form the complete tripeptide. The pathway is feedback-inhibited by GSH itself, which helps maintain steady intracellular levels. Tissues vary widely in glutathione content, with the liver typically containing the highest concentrations, followed by the kidneys, lungs, and erythrocytes. Because cysteine is often limiting, its availability influences synthesis rates, and regulation of this pathway varies by cell type.
Glutathione serves as a cofactor for several enzymes, including glutathione peroxidase and glutathione S-transferase. These enzymes help reduce hydrogen peroxide and lipid peroxides, and they conjugate reactive electrophiles for excretion. The molecule also acts as a reservoir for cysteine, an amino acid that is prone to oxidation. In addition, glutathione participates in the metabolism of nitric oxide, leukotrienes, and prostaglandins. Its roles extend to cell signaling, apoptosis, and the regulation of protein function through S-glutathionylation.
Commercial glutathione is produced by microbial fermentation or chemical synthesis, then purified. Reduced and oxidized grades are offered separately, with purity specifications often exceeding 98 percent. The compound appears in foods such as fresh fruits, vegetables, and meats, although cooking and processing can lower amounts. Oral, topical, and inhaled forms are discussed in research and consumer contexts, but absorption and tissue delivery remain active areas of study. Regulatory status varies by country and intended use.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | Reduced form (GSH) |
| Molar mass | 307.32 g/mol | For GSH; GSSG is 612.63 g/mol |
| Appearance | White crystalline powder | Usually lyophilized |
| Solubility in water | Freely soluble (≥100 mg/mL) | pH dependent |
| Typical storage | -20 °C, desiccated | Protect from light and oxygen |
Storage recommendations for glutathione reagents usually specify a cool, dry, dark environment because the thiol oxidizes in air and light. Solid material is often kept desiccated at low temperature, while solutions are prepared fresh or stored frozen in aliquots. Repeated freeze-thaw cycles can accelerate degradation, and metal ions can catalyze oxidation. Quality control may include purity assays, water content, and identity confirmation. Stability limits are method-specific, so a stated shelf life applies only to defined conditions and packaging.
Laboratory measurement of glutathione requires attention to oxidation before analysis. Blood, tissue, or cell samples can lose reduced glutathione as it converts to GSSG or forms mixed disulfides with proteins. Acid extraction, rapid freezing, and thiol-blocking reagents are common strategies to preserve the original distribution. Reported concentrations therefore depend on collection protocol, extraction method, and the time between sampling and analysis. Comparisons across studies are most reliable when these pre-analytical variables are described.
For solid glutathione reagents, storage at low temperature and protection from moisture and light are typical precautions. Aqueous solutions can oxidize over time, and pH affects stability; alkaline conditions generally promote thiol oxidation. Some protocols prepare fresh solutions, while others use antioxidants or chelators to limit metal-catalyzed oxidation. Purity and counterion content can vary among commercial preparations, affecting concentration calculations. Certificates of analysis and validated assays help verify identity and purity.
Measuring glutathione in biological samples requires attention to oxidation, because GSH can convert to GSSG after sample collection. Blood and plasma samples are often treated with acid or alkylating agents to preserve the reduced form. Without stabilization, apparent GSH concentrations can fall while GSSG rises. Differences in sample type, handling delay, and deproteinization method can produce results that are not comparable across studies. Reporting preanalytical details is therefore important for interpreting findings.
Common analytical approaches include enzymatic recycling assays, high-performance liquid chromatography, and mass spectrometry. Enzymatic recycling measures total glutathione after converting GSSG back to GSH, while separation methods can quantify GSH and GSSG separately. Derivatization may be used to improve detection or stability during analysis. LC-MS/MS offers high specificity and can distinguish glutathione from related thiols and adducts. Each method has different sensitivity, throughput, and susceptibility to interference, so method selection depends on the study question and sample matrix.
Samples for glutathione analysis require careful handling because the compound oxidizes readily and can be consumed by enzymes after collection. Blood is often treated with acid or thiol-blocking agents soon after draw, and plasma should be separated quickly from red blood cells. Tissues are usually snap-frozen or extracted immediately. Aqueous solutions of glutathione are less stable than dry powder and degrade faster at neutral or alkaline pH, in light, or with dissolved oxygen. Repeated freeze-thaw cycles also reduce reliability.
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.
Historically, an association between the color of blood and rust occurs in the association of the planet Mars, with the Roman god of war, since the planet is an orange-red, which reminded the ancients of blood. Although the color of the planet is due to iron compounds in combination with oxygen in the Martian soil, it is a common misconception that the iron in hemoglobin and its oxides gives blood its red color. The color is actually due to the porphyrin moiety of hemoglobin to which the iron is bound, not the iron itself, although the ligation and redox state of the iron can influence the pi to pi* or n to pi* electronic transitions of the porphyrin and hence its optical characteristics. Artist Julian Voss-Andreae created a sculpture called Heart of Steel (Hemoglobin) in 2005, based on the protein's backbone. The sculpture was made from glass and weathering steel. The intentional rusting of the initially shiny work of art mirrors hemoglobin's fundamental chemical reaction of oxygen binding to iron. Montreal artist Nicolas Baier created Lustre (Hémoglobine), a sculpture in stainless steel that shows the structure of the hemoglobin molecule. It is displayed in the atrium of McGill University Health Centre's research centre in Montreal. The sculpture measures about 10 metres × 10 metres × 10 metres.
== Sources == Samuel W. Mitcham (2007). German Order of Battle. Volume Two: 291st–999th Infantry Divisions, Named Infantry Divisions, and Special Divisions in WWII. Stackpole Books. ISBN 978-0-8117-3437-0, p. 148–149. Georg Tessin: Verbände und Truppen der deutschen Wehrmacht und Waffen-SS im Zweiten Weltkrieg 1939–1945. Volume 11. Die Landstreitkräfte 501–630. Biblio-Verlag, Bissendorf 1975, ISBN 3-7648-1181-1, p. 128.
== Books == Bhatia, Sangeeta (1999). Microfabrication in tissue engineering and bioartificial organs. Microsystems. Vol. 5. Boston: Kluwer Academic Publishers. doi:10.1007/978-1-4615-5235-2. ISBN 978-1-4613-7386-5. Palsson, Bernhard; Bhatia, Sangeeta (2004). Tissue engineering. Upper Saddle River, N.J.: Pearson Prentice Hall. ISBN 0-13-041696-7. OCLC 52960378. Nahmias, Yaakov; Bhatia, Sangeeta (2009). Microdevices in biology and medicine. Boston: Artech House. ISBN 978-1-59693-405-4. OCLC 542050628. Schultz, Jerome; Mrksich, Milan; Bhatia, Sangeeta N.; Brady, David J.; Ricco, Antionio J.; Walt, David R.; Wilkins, Charles L., eds. (July 15, 2006). Biosensing: International Research and Development. Springer Science & Business Media. ISBN 978-1-4020-4058-0.
=== Atmospheric sciences === In the atmospheric sciences, the vorticity equation can be stated in terms of the absolute vorticity of air with respect to an inertial frame, or of the vorticity with respect to the rotation of the Earth. The absolute version is
==== Unstructured ==== An unstructured repository may simply be a stack of tapes, DVD-Rs or external HDDs with minimal information about what was backed up and when. This method is the easiest to implement, but unlikely to achieve a high level of recoverability as it lacks automation.
Sources: en.wikipedia.org
=== 1970s === 1970: Australian geologist and palaeontologist Dorothy Hill became the first female president of the Australian Academy of Science. 1970: New Zealand geologist and palynologist Rosemary Askin the first New Zealand woman to undertake her own research programme in Antarctica. 1970: Spanish biochemist Margarita Salas discovered and characterized the Φ29 phage DNA polymerase. She was also the first scientific woman elected to the Royal Spanish Academy and was the first woman recipient of the Carlos J. Finlay Prize for Microbiology. 1970: Samira Islam became the first Saudi Arabian person to earn a PhD in pharmacology. 1970: American astronomer Vera Rubin published the first evidence for dark matter. 1970: Polish geologist Franciszka Szymakowska became widely known because of her unique and detailed geological drawings that are still used today. 1971: Romanian chemist Ecaterina Ciorănescu-Nenițescu became a member of the New York Chemical Society. She was noted for developing synthesis processes for antituberculosis drugs and insecticides and creating new substances using cytostatic grafting. 1973: American physicist Anna Coble became the first African-American woman to receive a PhD in biophysics, completing her dissertation at University of Illinois. 1974: Dominican marine biologist Idelisa Bonnelly founded the Dominican Republic Academy of Science. 1975: Indian chemist Asima Chatterjee was elected the General President of the Indian Science Congress Association. She simultaneously became the first female scientist ever elected a member of the congress.
In Thai cuisine, glass noodles are called wun sen (Thai: วุ้นเส้น). They are commonly mixed with pork and shrimp in a spicy salad called yam wun sen (Thai: ยำวุ้นเส้น), or stir-fried as phat wun sen (Thai: ผัดวุ้นเส้น) and sometimes used as the noodles for pad thai.
== Etymology == The name mercapturic acid is a combination of mercapturic and acid. The latter indicates that the compound is an acid. The former is a compound word consisting of the stem mercaptur-, coming from mercaptan, and the suffix -ic, meaning "having the character of". In sum, the name mercapturic acid means "an acid with mercaptan character/nature".
Oral progesterone (Prometrium) metabolizes into neurosteroids including allopregnanolone and pregnanolone which act as potent GABAA receptor positive allosteric modulators. As a result, oral progesterone can dose-dependently produce side effects including dizziness, drowsiness, sedation, somnolence, fatigue, anxiety reduction, euphoria, and cognitive impairment. For this reason, oral progesterone is often taken at night before bed. Oral progesterone taken before bed has been found to improve multiple sleep outcomes in clinical studies. Zuranolone is a synthetic analogue of allopregnanolone that likewise acts as a GABAA receptor positive allosteric modulator but is orally active. It is under development for the treatment of insomnia and is in phase 3 clinical trials for this indication as of September 2025.
== Sector quadrupole == A sector instrument can be combined with a collision quadrupole and quadrupole mass analyzer to form a hybrid instrument. A BEqQ configuration with a magnetic sector (B), electric sector (E), collision quadrupole (q) and m/z selection quadrupole (Q) have been constructed and an instrument with two electric sectors (BEEQ) has been described.
Sources: en.wikipedia.org
=== 21st century === In the 21st century, wholesaling has increasingly combined physical networks (ports, warehouses, cold chain) with digital coordination (catalogs, online ordering, forecasting, and platform-based matching). UN Trade and Development (UNCTAD) reports that business e-commerce sales grew strongly in recent years, reaching about $27 trillion in 2022 (across the economies included in its measurement work), highlighting how digital channels have become central to business purchasing and selling.
Like many Eastern spices, pepper was historically both a seasoning and a traditional medicine. Pepper appears in the Buddhist Samaññaphala Sutta, chapter five, as one of the few medicines a monk is allowed to carry. Long pepper, being stronger, was often the preferred medication, but both were used. Black pepper (or perhaps long pepper) was believed to cure several illnesses, such as constipation, insomnia, oral abscesses, sunburn, and toothaches, among others. Pepper contains phytochemicals, including amides, piperidines, and pyrrolidines. Pepper is known to cause sneezing. Some sources say that piperine, a substance present in black pepper, irritates the nostrils, causing the sneezing. Few, if any, controlled studies have been carried out to answer the question.
Norris was convicted by an 11-1 majority verdict on 3 March 2008 for the murder of four women, and the attempted murder of a fifth (Vera Wilby, aged 90). He was sentenced the following day to life imprisonment, and ordered to serve a minimum term of 30 years in prison. Norris had acted particularly aggressively throughout the trial, banging on the windows of the judge and attacking members of the press when departing the court, shoving two against a wall. Pictures of these attacks were not shown on television for fear of influencing the jury. The judge told Norris when sentencing: "You are, I have absolutely no doubt, a thoroughly evil and dangerous man. You are an arrogant and manipulative man with a real dislike of elderly patients. The most telling evidence was that observation of one of your patients, Bridget Tarpey, who said 'he did not like us old women'. My view is you did not like them because they required too much nursing and were too demanding of your time. You are in my judgment essentially lazy as evidenced by your absences from student placements and work." Norris's mother June Morrison said he had made her so proud as he grew to be successful in his chosen profession. Referred to in the British press as the "Angel of Death", Norris was convicted of killing his victims by injecting them with high levels of insulin. The four victims were:
Even edible mushrooms may produce allergic reactions in susceptible individuals, from a mild asthmatic response to severe anaphylactic shock. Even the cultivated A. bisporus contains small amounts of hydrazines, the most abundant of which is agaritine (a mycotoxin and carcinogen). However, the hydrazines are destroyed by moderate heat when cooking. A number of species of mushrooms are poisonous; although some resemble certain edible species, consuming them could be fatal. Eating mushrooms gathered in the wild is risky and should only be undertaken by individuals knowledgeable in mushroom identification. Common best practice is for wild mushroom pickers to focus on collecting a small number of visually distinctive, edible mushroom species that cannot be easily confused with poisonous varieties. Common mushroom hunting advice is that if a mushroom cannot be positively identified, it should be considered poisonous and not eaten. In Jainism, the consumption of mushrooms and other edible fungi is strictly prohibited. This dietary restriction is fundamentally rooted in the religion's core ethical principle of nonviolence (ahimsa). Classical Jain taxonomy classifies mushrooms as ananthkay, meaning they are considered to be bodies that harbor an infinite number of microscopic souls or lifeforms (nigoda). Furthermore, because mushrooms frequently grow in dark environments or on decaying organic matter, traditional Jain biology views them as continuous breeding grounds for mobile microorganisms (trasa jiva).
Acetone peroxide ( also called APEX and mother of Satan) is an organic peroxide and a primary explosive. It is produced by the reaction of acetone, hydrogen peroxide and a strong acidic catalyst to yield a mixture of linear monomer and cyclic dimer, trimer, and tetramer forms. The monomer is dimethyldioxirane. The dimer is known as diacetone diperoxide (DADP). The trimer is known as triacetone triperoxide (TATP) or tri-cyclic acetone peroxide (TCAP). Acetone peroxide takes the form of a white crystalline powder with a distinctive bleach-like odor when impure, or a fruit-like smell when pure, and can explode powerfully if subjected to heat, friction, static electricity, concentrated sulfuric acid, strong UV radiation, or shock. Until about 2015, explosives detectors were not set to detect non-nitrogenous explosives, as most explosives used preceding 2015 were nitrogen-based. TATP, being nitrogen-free, has been used as the explosive of choice in several terrorist bomb attacks since 2001.
Sources: en.wikipedia.org
Glutathione is a tripeptide of three amino acids: glutamate, cysteine, and glycine. The cysteine residue provides the sulfhydryl group that gives the molecule its reducing properties.
GSH is the reduced form, which contains a free sulfhydryl group. GSSG is the oxidized form, formed when two GSH molecules join through a disulfide bond. The ratio of GSH to GSSG is often used to assess cellular redox status.
No, glutathione is synthesized endogenously in most cells. It is not classified as an essential nutrient because the body can produce it from amino acid precursors. Dietary sources exist, but they are not required to maintain life.
It is a tripeptide rather than a full protein. Proteins generally contain many amino acids joined by alpha-peptide bonds, while glutathione has three residues and an unusual gamma-glutamyl linkage. That structure affects how enzymes recognize and break it down.