A practical reference on thiol: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-12. Anything still debated is marked as such rather than presented as settled.
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.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group of glutamate rather than the alpha-carboxyl group. This unusual linkage protects the molecule from many common peptidases. The cysteine side chain carries a thiol group that can undergo reversible oxidation. Because of this thiol, glutathione participates in redox reactions and helps maintain the reducing environment inside most cells in living systems.
In cells, glutathione exists mainly in a reduced form called GSH. When two GSH molecules react, they form oxidized glutathione, or GSSG, which contains a disulfide bond. The ratio of GSH to GSSG is often used as an indicator of oxidative stress. Enzymes such as glutathione peroxidase and glutathione reductase help cycle the molecule between these two states. This cycling supports antioxidant defense, detoxification of reactive molecules, and regulation of certain signaling pathways.
| 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 |
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.
Biosynthesis proceeds in two ATP-dependent steps. First, glutamate-cysteine ligase joins glutamate and cysteine. Second, glutathione synthetase adds glycine to the intermediate. The pathway is regulated by cysteine availability, enzyme expression, and feedback inhibition by glutathione itself. Liver tissue has a particularly high capacity for synthesis and export. Because the molecule is made inside cells, circulating glutathione reflects a balance of release, uptake, and breakdown rather than simple dietary supply.
Functionally, glutathione supports redox balance by donating electrons and becoming oxidized. It also serves as a cofactor for enzymes such as glutathione peroxidases and glutathione S-transferases. These enzymes participate in peroxide reduction and in conjugation reactions that help process reactive molecules. Separate from antioxidant roles, glutathione can modify protein cysteines through S-glutathionylation, influencing enzyme activity and signaling. Research continues to examine how these chemical roles translate into whole-organism effects.
Another interpretation, using density functional theory calculation, goes as follows: C=C with defects such as functional groups and pentagons (283.6 eV), C=C (non-oxygenated ring contexts) (284.3 eV), sp3C-H in the basal plane and C=C with functional groups (285.0 eV), C=O and C=C with functional groups, C-O (286.5 eV), and O-C=O (288.3 eV). Graphite oxide is hydrophilic and easily hydrated when exposed to water vapor or immersed in liquid water, resulting in a distinct increase of the inter-planar distance (up to 1.2 nm in saturated state). Additional water is also incorporated into the interlayer space due to high pressure induced effects. The maximal hydration state of graphite oxide in liquid water corresponds to insertion of 2-3 water monolayers. Cooling the graphite oxide/H2O samples results in "pseudo-negative thermal expansion" and cooling below the freezing point of water results in de-insertion of one water monolayer and lattice contraction. Complete removal of water from the structure seems difficult since heating at 60–80 °C results in partial decomposition and degradation of the material.
RNA-targeted therapies are being explored for severe genetic epilepsies; for example, ASO-mediated knockdown of KCNT1 has been investigated as an experimental approach for KCNT1-associated epileptic encephalopathy in humans, as well as in prenatal models. Non-viral vectors, virus vectors and liposomes have been used to deliver the antisense RNA through the cell membrane into the cytoplasm and nucleus. It has been found that the viral vector based delivery is the most advantageous among different delivery systems because it has a high transfection efficacy. However, it is difficult to deliver antisense RNA only to the targeted sites. Also, due to the size and the stability issues of antisense RNA, there are some limitations to its use. To improve the delivery issues, chemical modifications, and new oligonucleotide designs have been studied to enhance the drug distribution, side effects, and tolerability.
=== 1994–1999: The Double Trio, Vrooom, Thrak and the ProjeKcts === In the summer of 1991, Belew met with Fripp in England to express an interest in reviving King Crimson. That year saw the release of the retrospective box set Frame by Frame: The Essential King Crimson. A follow-up box set, The Great Deceiver, appeared the following year as the first release on Fripp's newly-established record label Discipline Global Mobile (DGM), formed with producer David Singleton. Subsequently, DGM would be the primary home for Fripp's work, with larger album releases distributed to bigger record companies (initially Virgin Records), and smaller releases handled by DGM. This afforded Fripp and his associates greater creative freedom and more control over all aspects of their work.
Sources: en.wikipedia.org
The sermon images were "of pure Gandhara style". Their style was very close to those of the "Cave of the Painters (Cave 207)", and, according to Grünwedel, "they seem to have been executed by the same hand". Albert Grünwedel attributed both caves to the same "Stage I" period (500–600 CE). Several fine fragments of very fine painting have reached us, which are attributed to the Cave of the Statues. Grünwedel explained that only three paintings remained in the cella, all scenes of the sermon of the Buddha: 1) On the right wall of the cella, Grünwedel described the picture of a sermon, with "a youth in light undergarment praying in front of Buddha", corresponding to the picture now described as the "cowherd Nanda", known to have come from the Cave of the Statues. 2) In the opposite location, on the left wall, Grünwedel described a sermon scene in which the Buddha "only had his feet remaining", corresponding to the panel photographed by Charles Nouette in-situ in 1907. 3) Finally Grünwedel described a sermon scene with only a "kneeling adorant" remaining, corresponding to the kneeling Vajrapani, known to have come from the Cave of the Statues. The style of these panels from the main cella is markedly different from the refined, "classical" style of the side corridor vaults and the back corridor. They suggests different painters and different schools of art. In the cella, the paintings are much bolder, using intense colors, thicker lines and simpler patterns, as in the "Cowherd Nanda".
Even with all the precautions taken by medical professionals, infection reportedly occurs in up to 13.9% of patients after stabilization of an open fracture, and in about 0.5-2% of patients who receive joint prostheses. To reduce these numbers, the surfaces of the devices used in these procedures have been altered in hopes of preventing the growth of the bacteria that leads to these infections. This has been achieved by coating titanium devices with an antiseptic combination of chlorhexidine and chloroxylenol. This antiseptic combination successfully prevents the growth of the five main organisms that cause medical-related infections, which include Staphylococcus epidermidis, Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Peptide-based gel coating with intrinsic antibacterial activity against Methicillin-resistant Staphylococcus aureus, was also shown to inhibit colonization of titanium implants in mice.
When a DU penetrator reaches the interior of an armored vehicle, it catches fire, often igniting ammunition and fuel and possibly causing the vehicle to explode. DU is used by the U.S. Army in 120 mm or 105 mm cannons employed on the M1 Abrams tank. The DU content in various ammunition is 180 grams (6.3 oz) in 20 mm, 200 grams (7.1 oz) in 25 mm, 280 grams (9.9 oz) in 30 mm, 3.5 kilograms (7.7 lb) in 105 mm, and 4.5 kilograms (9.9 lb) in 120 mm penetrators. DU was used during the mid-1990s in the U.S. to make hand grenades, and land mines, but those applications have been discontinued, according to Alliant Techsystems. The US Navy used DU in its 20 mm Phalanx CIWS guns, but switched in the late 1990s to armor-piercing tungsten. Only the US and the UK have acknowledged using DU weapons. The Soviet Union and Russia have used DU weaponry since the 3BM-32 Vant, designed for the 125 mm tank cannons. In 2018, TASS reported that Russia was arming some of its T-80 models with 3BM60 Svinets-2 DU rounds. 782,414 DU rounds were fired during the 1991 war in Iraq, mostly by US forces. In a three-week period of conflict in Iraq during 2003, it was estimated that between 1,000 and 2,000 tonnes of depleted uranium munitions were used. More than 300,000 DU rounds were fired during the 2003 war, the vast majority by US troops.
Sources: en.wikipedia.org
Dihydrowogonin is a natural product, which as a flavonoid belongs to the flavanone subclass. It has a flavan backbone with a hydroxyl and methoxy functional groups. It possesses some antioxidant, anti-inflammatory, and neuroprotective properties. Dihydrowogonin has been identified as a major constituent in the methanol extract of the species, Prunus avium (wild cherry), mostly in the bark. Dihydrowogonin appears to exhibit antimicrobial and antibiofilm behaviour, particularly against the Gram-positive bacteria like Staphylococcus aureus. In addition, it can interact with glutathione transferases in white-rot fungi; thus, this suggests a role in the detoxification processes during wood degradation. It has been studied for potential applications in pharmacology, particularly as an antimicrobial and antioxidant agent, and in neuroprotective therapies.
== Interactions == Meropenem rapidly reduces serum concentrations of valproic acid. As a result, people who use valproic acid for epilepsy are at increased risk of seizures during treatment with meropenem. In situations where the use of meropenem cannot be avoided, prescription of an additional anticonvulsant should be considered.
== Personal life == Fenn married Margaret Wilson at the end of his second year of graduate studies. Together, they had three children – two daughters and a son. Margaret was killed in a car accident in New Zealand in 1992. Fenn remarried, his second wife was named Frederica Mullen. He died in Richmond, Virginia on December 10, 2010, at the age of 93, exactly 8 years to the day after receiving his Nobel Prize. Fenn was survived by Frederica, his three children, seven grandchildren, and eleven great-grandchildren: Anika Fenn Gilman, Nora Fenn Gilman, Dominick Brown, Aaron Holloway, Michelle Holloway, Damarion Holloway, Tyrell Holloway, Eloise Whittington, JC Leslie, Manon Leslie, and Dino Steinberg.
== Contraindications == Dihydroergotamine is contraindicated with potent CYP3A4 inhibitors, like macrolide antibiotics. Contraindications for dihydroergotamine include: pregnancy, kidney failure or liver failure, coronary, cerebral, and peripheral vascular disease, hypersensitivity reactions, sepsis, and uncontrolled hypertension.
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.
Glutathione is a tripeptide made from glutamate, cysteine, and glycine. Its cysteine residue provides a thiol group that is central to its redox activity. The glutamate-cysteine bond forms through the gamma-carboxyl group of glutamate.