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Chemical Identity And Natural Occurrence — Reference Sheet

By Editorial Desk · published 2025-09-19 · last reviewed 2025-10-18 · Wiki

The short version of glutathione fits in a sentence. The long version — which is the one that helps — is below.

This page was last updated on 2025-10-18 and is reviewed periodically as new material appears.

Chemical Identity and Natural Occurrence

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.

Background and Biochemical Role

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.

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 at a glance

PropertyValueNotes
Chemical formulaC10H17N3O6SReduced glutathione (GSH)
Molar mass307.32 g/molCalculated for C10H17N3O6S
AppearanceWhite to off-white powderTypical solid form
SolubilityWater-solublePolar tripeptide
Common synonymsGSH; L-glutathioneGamma-glutamylcysteinylglycine

Biochemical Roles and Redox Balance

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 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.

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Background and Molecular Function

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.

Glutathione Background and Cellular Functions

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 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.

Notes from published material

Brain Basal ganglia Brain stem Medulla Midbrain Pons Cerebellum Cerebrum Cerebral cortex Hypothalamus Limbic system Amygdala Eyes (2) Pineal gland Pituitary gland Thyroid gland Parathyroid glands (4) Thorax

== Packaging and ingredients == The size content of energy gels is commonly 1.2 oz (32g), with a range from 1 oz to 1.5 oz packets. The portable packaging is designed to facilitate uninterrupted training or performance conditions. Common ingredients include water, maltodextrin, fructose, and various micronutrients, preservatives, and flavor compounds or caffeine.

Sheikh Sāleḥ bin Fawzān bin ‘Abd Allāh al-Fawzān (born 28 September 1935) is a Saudi Islamic scholar who is the fourth and current Grand Mufti of Saudi Arabia, serving since 22 October 2025. He is regarded as one of the senior scholars within the Salafi movement. Al-Fawzan is also a member of Saudi Arabia's Council of Senior Scholars and the fiqh council in Mecca, affiliated with the Muslim World League. He also serves as a member of the Supervisory Committee for Preachers during Hajj, and a member of the Permanent Committee for Scholarly Research and Ifta in the Saudi Arabia. In addition to this, he is an imam, khatib and teacher at the Prince Mutaib bin Abdulaziz Al Saud Mosque in Riyadh. He participates in the radio program Nūr 'Alā al-Darb, answering questions on Islamic topics, and contributes to scholarly journals in the form of research, studies, letters, and fatwas.

== Definition == Vitamin K refers to several structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. These are similar in structure in that they share a quinone ring, but differ in the length and degree of saturation of the carbon tail and the number of repeating isoprene units in the side chain (see figures in § Chemistry). Plant-sourced forms are primarily vitamin K1. Animal-sourced foods are primarily vitamin K2. Vitamin K has several roles: an essential nutrient absorbed from food, a product synthesized and marketed as part of a multi-vitamin or as a single-vitamin dietary supplement, and a prescription medication for specific purposes.

Their intention was to protect Raleigh from the destruction inflicted on other cities by Union troops. Graham and Swain departed to meet the advancing Federal forces on the morning of April 12, 1865, and were to return by that evening. The evening struck, but Graham and Swain had not returned due to train delays and their temporary capture by Sherman. Governor Vance left the evening after Graham and Sherman failed to return, leaving behind a letter giving Mayor William H. Harrison the authority to surrender. On the morning of April 13, Mayor Harrison among others went to the southern Wake County area to meet General Hugh Judson Kilpatrick and propose surrender. Kenneth Rayner, a long-time resident of Raleigh, delivered the proposal including a promise of no resistance. Kilpatrick agreed to accept the surrender and protect Raleigh from destruction. Kilpatrick's cavalry occupied Raleigh and removed the flagpole from the state capitol, replacing it with a United States Flag above the dome. Sherman arrived shortly after and established his headquarters in the governor's mansion. The city was spared significant destruction during the war. As Confederate cavalry retreated west, Union soldiers followed, leading to the Battle of Morrisville nearby. Due to the economic and social problems of the postwar period and Reconstruction, with a state economy still heavily dependent on agriculture, the city grew little over the next several decades. Shaw University, the South's first African American college, began classes in 1865 and was chartered in 1875.

Sources: en.wikipedia.org

Further detail

=== Orthologs === There are currently 193 organisms that are known to be orthologs of EPCIP. The orthologs of EPCIP are deuterostome animals in the clade Chordata. Table 3 shows a range of EPCIP orthologs, their NCBI accession numbers, sequence lengths, and sequence identity to the EPCIP human protein. At this time, EPCIP is not known to have any protostome or invertebrate orthologs.

=== Storage and disposal === The fentanyl patch is one of a few medications that may be especially harmful, and in some cases fatal, with just one dose, if misused by a child. In British Columbia, Canada, where there are environmental concerns about toilet flushing or garbage disposal, pharmacists recommend that unused patches be sealed in a child-proof container that is then returned to a pharmacy. In the United States, where patches cannot always be returned through a medication take-back program, flushing is recommended for fentanyl patches, because it is the fastest and surest way to remove them from the home, preventing ingestion by children, pets or others not intended to use them.

NRF2, a transcription factor associated with the cellular response to oxidative stress, has been found to be indirectly regulated by O-GlcNAc. KEAP1, an adaptor protein for the cullin 3-dependent E3 ubiquitin ligase complex, mediates the degradation of NRF2; oxidative stress leads to conformational changes in KEAP1 that repress degradation of NRF2. O-GlcNAc modification of KEAP1 at S104 is required for efficient ubiquitination and subsequent degradation of NRF2, linking O-GlcNAc to oxidative stress. Glucose deprivation leads to a reduction in O-GlcNAc and reduces NRF2 degradation. Cells expressing a KEAP1 S104A mutant are resistant to erastin-induced ferroptosis, consistent with higher NRF2 levels upon removal of S104 O-GlcNAc. Elevated O-GlcNAc levels have been associated with diminished synthesis of hepatic glutathione, an important cellular antioxidant. Acetaminophen overdose leads to accumulation of the strongly oxidizing metabolite NAPQI in the liver, which is detoxified by glutathione. In mice, OGT knockout has a protective effect against acetaminophen-induced liver injury, while OGA inhibition with thiamet-G exacerbates acetaminophen-induced liver injury.

=== Generic names === Clomipramine is the English and French generic name of the drug and its INNTooltip International Nonproprietary Name, BANTooltip British Approved Name, and DCFTooltip Dénomination Commune Française, while clomipramine hydrochloride is its USANTooltip United States Adopted Name, USPTooltip United States Pharmacopeia, BANMTooltip British Approved Name, and JANTooltip Japanese Accepted Name. Clomipramina is its generic name in Spanish, Portuguese and Italian and its DCITTooltip Denominazione Comune Italiana, while clomipramin is its generic name in German and clomipraminum is its generic name in Latin.

Sources: en.wikipedia.org

Frequently asked questions

What substances combine to form glutathione?

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.

Where is glutathione found in the body?

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.

Is glutathione an essential nutrient?

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.

What is glutathione made of?

It is a tripeptide of glutamic acid, cysteine, and glycine. The linkage between glutamate and cysteine uses the gamma-carboxyl group, which is unusual for peptides.

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