Everything below concerns LC-MS/MS. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Measuring glutathione in biological samples requires attention to oxidation and matrix effects. High-performance liquid chromatography with ultraviolet or fluorescence detection can separate reduced and oxidized forms after derivatization. Liquid chromatography with tandem mass spectrometry offers higher specificity and can quantify glutathione alongside related thiols. Because glutathione can oxidize during sample handling, many protocols use rapid acidification with metaphosphoric acid or sulfosalicylic acid. Internal standards help correct for losses during extraction and analysis.
Enzymatic recycling assays provide a complementary approach for total glutathione. In these methods, glutathione reductase reduces oxidized glutathione while a thiol-reactive reagent, such as 5,5'-dithiobis(2-nitrobenzoic acid), produces a colored product. The reaction cycles between reduced and oxidized forms, amplifying the signal. Spectrophotometric or fluorometric detection can then estimate concentration. Distinguishing reduced glutathione from glutathione disulfide often requires separate aliquots, masking agents, or chromatographic separation, and the choice affects reported values.
Storage conditions strongly influence glutathione stability. The solid reduced form is commonly kept desiccated at or below minus twenty degrees Celsius, protected from light and moisture. Aqueous solutions are less stable because the thiol group reacts with dissolved oxygen, and oxidation accelerates at neutral or alkaline pH. Acidic solutions and oxygen-free handling can slow degradation, but repeated freeze-thaw cycles should be avoided. Researchers often verify concentration before use, because apparent losses can arise from oxidation or water uptake.
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.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C | Desiccated, protected from light |
| Solution stability | Hours to days at neutral pH | Acidic pH and low oxygen slow oxidation |
| Oxidized form | Glutathione disulfide (GSSG) | Formed by thiol oxidation |
| Typical analytical method | LC-MS/MS or enzymatic recycling | Choice depends on matrix and specificity |
| Thiol pKa | Approximately 9.2 | Influences reactivity at physiological pH |
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.
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.
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.
Glutathione is present in most tissues, with especially high concentrations in the liver. It also serves as a cofactor for some enzymes and helps transport amino acids across cell membranes. In plants and microorganisms, glutathione contributes to stress responses and metal handling. The molecule is synthesized in two ATP-dependent steps, first producing gamma-glutamylcysteine and then adding glycine. Because cysteine availability often limits synthesis, dietary and metabolic factors can influence glutathione levels. Research continues to examine how these levels relate to health and disease.
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.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine, and it is the most abundant non-protein thiol in most living cells. The reduced form, GSH, carries a sulfhydryl group that can donate electrons, while the oxidized form, GSSG, forms when two GSH molecules link via a disulfide bond. The balance between these two forms helps define the cellular redox environment, and their ratio is often used as an indicator of oxidative stress. Because the sulfhydryl group is reactive, glutathione participates in many cellular processes, including detoxification and protein regulation.
On November 21, 2006, EPA ordered DuPont to offer alternative drinking water or treatment for public or private water users living near DuPont's Washington Works plant in West Virginia (and in Ohio), if the level of PFOA detected in drinking water is equal to or greater than 0.5 parts per billion. This measure sharply lowered the previous action level of 150 parts per billion that was established in March 2002. According to a May 23, 2007, Environmental Science & Technology Online article, U.S. Food and Drug Administration research regarding food contact papers as a potential source of PFOA to humans is ongoing. In November 2007, the Centers for Disease Control and Prevention (CDC) published data on PFOA concentrations comparing 1999–2000 vs. 2003–2004 NHANES samples. In October 2021 the EPA proposed to designate PFOA and PFOS as hazardous substances in its PFAS Strategic Roadmap. In September 2022 the EPA proposed to designate as hazardous substances under the Superfund Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). In 2024 EPA published drinking water regulations for PFOA and five other PFAS.
In August 2025, Moore's chief of staff, Fagan Harris, announced that he would resign his post at the end of the year to become the next president of the Abell Foundation; he was succeeded by Lester Davis, a CareFirst BlueCross BlueShield executive who worked as an unpaid outside advisor to Moore's 2022 gubernatorial campaign. In October 2025, Roland Butler resigned as secretary of state police and was succeeded by state senator Michael A. Jackson. In November 2025, Paul Monteiro resigned as secretary of Maryland Department of Service and Civic Innovation and was succeeded by Jonny Dorsey, one of Moore's deputy chiefs of staff. In October 2025, Moore appointed Walter Simmons to serve as the secretary of the newly created Department of Social and Economic Mobility. Two of Moore's cabinet secretaries resigned in 2026. Maryland Secretary of Human Services Rafael López, who resigned on February 23, citing health reasons, and was succeeded by deputy secretary Gloria Brown Burnett, who will serve as acting secretary until April 1, when Stacy Rodgers will then take over as acting secretary. In March 2026, Rai announced that he would step down on March 27, and would be succeeded by deputy secretary Elena Quiroz-Livanis, who will serve as acting secretary until a search for a new, permanent secretary is completed.
UPMC has its roots in the 1893 establishment of Presbyterian Hospital, which serves as the medical center's flagship facility, and the 1886 founding of the Western Pennsylvania Medical College. Soon after its founding, the medical college became affiliated with the Western University of Pennsylvania in 1892, and in 1908, was fully integrated into the university which that same year was renamed to the University of Pittsburgh. Already having informal agreements for teaching and staffing privileges with a number of local hospitals, Pitt and its School of Medicine desired to establish an academic medical center, and by the mid-1920s had formed a plan with city hospitals to have them relocate to the Oakland neighborhood where the university had moved in 1909. The university provided Presbyterian Hospital on the North Side, with a tract of land on its campus to construct a new hospital which broke ground in 1930 and opened in 1938. By the end of the 1930s, the University of Pittsburgh had helped to form the "University Medical Center" including Falk Clinic, Children's, Eye and Ear, Libby Steele Magee, Presbyterian General, and Women's Hospital, as well as the planned Municipal Hospital. In 1949, a new agreement between the university and Presbyterian Hospital established a three-tiered mission of patient care, research, and education, and by 1951, the hospital name was changed to Presbyterian University Hospital to reflect its close ties with the University of Pittsburgh.
Sources: en.wikipedia.org
Homebake (or home-bake) is a slang name most commonly used in Australia, and New Zealand for non-prescription opioids. The term refers to a crude mix of opioid class of drugs such as heroin, morphine and monoacetylated derivatives produced from pharmaceutical morphine tablets or morphine that has been produced through the demethylation of codeine when it is difficult to obtain heroin.
=== From lifestyle === Habitual snoring may be a risk factor for MASLD. Severe snoring often signals the presence of obstructive sleep apnea (OSA), a much more serious breathing condition. Blockage or narrowing of the airways, even temporarily, can cause the body to experience lowered oxygen levels in the blood. This, in turn, may cause a variety of changes within the body, such as tissue inflammation, increased insulin resistance, and liver injury. A prospective cohort study found the association between habitual snoring and MASLD development to be significant, and the trend was noted to be most prominent in lean individuals.
With the goal of mitigating these disadvantages while applying nanotechnology to electronics, researchers at the National Science Foundation's Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing (CHN) at Northeastern University with partners UMass Lowell and University of New Hampshire have developed a directed assembly process of single-walled carbon nano tube (SWNT) networks to create a circuit template that can be transfer from one substrate to another.
=== EC 1.3.1 With NAD+ or NADP+ as acceptor === EC 1.3.1.1: dihydrouracil dehydrogenase (NAD+) EC 1.3.1.2: dihydropyrimidine dehydrogenase (NADP+) EC 1.3.1.3: Δ4-3-oxosteroid 5β-reductase EC 1.3.1.4: transferred to EC 1.3.1.22, 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.5: cucurbitacin Δ23-reductase EC 1.3.1.6: fumarate reductase (NADH) EC 1.3.1.7: meso-tartrate dehydrogenase EC 1.3.1.8: acyl-CoA dehydrogenase (NADP+) EC 1.3.1.9: enoyl-[acyl-carrier-protein] reductase (NADH) EC 1.3.1.10: enoyl-[acyl-carrier-protein] reductase (NADPH, Si-specific) EC 1.3.1.11: 2-coumarate reductase EC 1.3.1.12: prephenate dehydrogenase EC 1.3.1.13: prephenate dehydrogenase (NADP+) EC 1.3.1.14: dihydroorotate dehydrogenase (NAD+) EC 1.3.1.15: dihydroorotate dehydrogenase (NADP+) EC 1.3.1.16: β-nitroacrylate reductase EC 1.3.1.17: 3-methyleneoxindole reductase EC 1.3.1.18: kynurenate-7,8-dihydrodiol dehydrogenase EC 1.3.1.19: cis-1,2-dihydrobenzene-1,2-diol dehydrogenase EC 1.3.1.20: trans-1,2-dihydrobenzene-1,2-diol dehydrogenase EC 1.3.1.21: 7-dehydrocholesterol reductase EC 1.3.1.22: 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.23: Identical to EC 1.3.1.3, Δ4-3-oxosteroid 5β-reductase EC 1.3.1.24: biliverdin reductase EC 1.3.1.25: 1,6-dihydroxycyclohexa-2,4-diene-1-carboxylate dehydrogenase EC 1.3.1.26: Now EC 1.17.1.8, 4-hydroxy-tetrahydrodipicolinate reductase EC 1.3.1.27: 2-hexadecenal reductase EC 1.3.1.28: 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase EC 1.3.1.29: cis-1,2-dihydro-1,2-dihydroxynaphthalene dehydrogenase EC 1.3.1.30: transferred to EC 1.3.1.22, 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.31: 2-enoate reductase EC 1.3.1.32: maleylacetate reductase EC 1.3.1.33: protochlorophyllide reductase EC 1.3.1.34: 2,4 Dienoyl-CoA reductase (NADPH) EC 1.3.1.35: Now EC 1.14.19.22, microsomal oleoyl-lipid 12-desaturase EC 1.3.1.36: geissoschizine dehydrogenase EC 1.3.1.37: cis-2-enoyl-CoA reductase (NADPH) EC 1.3.1.38: trans-2-enoyl-CoA reductase (NADPH) EC 1.3.1.39: trans-2-enoyl-CoA reductase (NADPH) EC 1.3.1.40: 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate reductase EC 1.3.1.41: xanthommatin reductase EC 1.3.1.42: 12-oxophytodienoate reductase EC 1.3.1.43: arogenate dehydrogenase EC 1.3.1.44: trans-2-enoyl-CoA reductase (NAD+) EC 1.3.1.45: 2′-hydroxyisoflavone reductase EC 1.3.1.46: biochanin-A reductase EC 1.3.1.47: α-santonin 1,2-reductase EC 1.3.1.48: 13,14-dehydro-15-oxoprostaglandin 13-reductase EC 1.3.1.49: cis-3,4-dihydrophenanthrene-3,4-diol dehydrogenase EC 1.3.1.50: n Now EC 1.1.1.252 tetrahydroxynaphthalene reductase EC 1.3.1.51: 2′-hydroxydaidzein reductase EC 1.3.1.52: Now EC 1.3.8.5, 2-methyl-branched-chain-enoyl-CoA reductase EC 1.3.1.53: (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase EC 1.3.1.54: precorrin-6A reductase EC 1.3.1.55: identical to EC 1.3.1.25, 1,6-dihydroxycyclohexa-2,4-diene-1-carboxylate dehydrogenase EC 1.3.1.56: cis-2,3-dihydrobiphenyl-2,3-diol dehydrogenase EC 1.3.1.57: phloroglucinol reductase EC 1.3.1.58: 2,3-dihydroxy-2,3-dihydro-p-cumate dehydrogenase EC 1.3.1.59: There is no evidence that the enzyme exists EC 1.3.1.60: dibenzothiophene dihydrodiol dehydrogenase EC 1.3.1.61: identical to EC 1.3.1.53, (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase EC 1.3.1.62: pimeloyl-CoA dehydrogenase EC 1.3.1.63: Now EC 1.21.1.2, 2,4-dichlorobenzoyl-CoA reductase EC 1.3.1.64: phthalate 4,5-cis-dihydrodiol dehydrogenase EC 1.3.1.65: 5,6-dihydroxy-3-methyl-2-oxo-1,2,5,6-tetrahydroquinoline dehydrogenase EC 1.3.1.66: cis-dihydroethylcatechol dehydrogenase EC 1.3.1.67: cis-1,2-dihydroxy-4-methylcyclohexa-3,5-diene-1-carboxylate dehydrogenase EC 1.3.1.68: 1,2-dihydroxy-6-methylcyclohexa-3,5-dienecarboxylate dehydrogenase EC 1.3.1.69: zeatin reductase EC 1.3.1.70: Δ14-sterol reductase EC 1.3.1.71: Δ24(241)-sterol reductase EC 1.3.1.72: Δ24-sterol reductase EC 1.3.1.73: 1,2-dihydrovomilenine reductase EC 1.3.1.74: 2-alkenal reductase [NAD(P)+] EC 1.3.1.75: 3,8-divinyl protochlorophyllide a 8-vinyl-reductase (NADPH) EC 1.3.1.76: precorrin-2 dehydrogenase EC 1.3.1.77: anthocyanidin reductase [(2R,3R)-flavan-3-ol-forming] EC 1.3.1.78: arogenate dehydrogenase (NADP+) EC 1.3.1.79: arogenate dehydrogenase (NAD(P)+) EC 1.3.1.80: Now classified as EC 1.3.7.12, red chlorophyll catabolite reductase EC 1.3.1.81: (+)-pulegone reductase EC 1.3.1.82: (-)-isopiperitenone reductase EC 1.3.1.83: geranylgeranyl diphosphate reductase EC 1.3.1.84: acrylyl-CoA reductase (NADPH) EC 1.3.1.85: crotonyl-CoA carboxylase/reductase EC 1.3.1.86: crotonyl-CoA reductase EC 1.3.1.87: 3-(cis-5,6-dihydroxycyclohexa-1,3-dien-1-yl)propanoate dehydrogenase EC 1.3.1.88: tRNA-dihydrouridine16/17 synthase (NAD(P)+) EC 1.3.1.89: tRNA-dihydrouridine47 synthase (NAD(P)+) EC 1.3.1.90: tRNA-dihydrouridine20a/20b synthase (NAD(P)+) EC 1.3.1.91: tRNA-dihydrouridine20 synthase (NAD(P)+) EC 1.3.1.92: artemisinic aldehyde Δ11(13)-reductase EC 1.3.1.93: very-long-chain enoyl-CoA reductase EC 1.3.1.94: polyprenol reductase EC 1.3.1.95: acrylyl-CoA reductase (NADH) EC 1.3.1.96: Botryococcus squalene synthase EC 1.3.1.97: botryococcene synthase EC 1.3.1.98: Now known to be catalyzed by two different enzymes, EC 1.3.1.122, (S)-8-oxocitronellyl enol synthase, and EC 5.5.1.34, (+)-cis,trans-nepetalactol synthase EC 1.3.1.100: chanoclavine-I aldehyde reductase EC 1.3.1.101: 2,3-bis-O-geranylgeranyl-sn-glycerol 1-phosphate reductase [NAD(P)H] EC 1.3.1.102: 2-alkenal reductase (NADP+) EC 1.3.1.103: 2-haloacrylate reductase EC 1.3.1.104: enoyl-[acyl-carrier-protein] reductase (NADPH) EC 1.3.1.105: 2-methylene-furan-3-one reductase EC 1.3.1.106: cobalt-precorrin-6A reductase EC 1.3.1.107: sanguinarine reductase EC 1.3.1.108: caffeoyl-CoA reductase EC 1.3.1.109: butanoyl-CoA dehydrogenase complex (NAD+, ferredoxin) EC 1.3.1.110: lactate dehydrogenase (NAD+,ferredoxin) EC 1.3.1.111: geranylgeranyl-bacteriochlorophyllide a reductase EC 1.3.1.112: anthocyanidin reductase [(2S)-flavan-3-ol-forming] EC 1.3.1.113: (4-alkanoyl-5-oxo-2,5-dihydrofuran-3-yl)methyl phosphate reductase EC 1.3.1.114: 3-dehydro-bile acid Δ4,6-reductase EC 1.3.1.115: 3-oxocholoyl-CoA 4-desaturase EC 1.3.1.116: 7β-hydroxy-3-oxochol-24-oyl-CoA 4-desaturase EC 1.3.1.117: hydroxycinnamoyl-CoA reductase EC 1.3.1.118: meromycolic acid enoyl-[acyl-carrier-protein] reductase EC 1.3.1.119: chlorobenzene dihydrodiol dehydrogenase EC 1.3.1.120: cyclohexane-1-carbonyl-CoA reductase NADP+) EC 1.3.1.121: 4-amino-4-deoxyprephenate dehydrogenase EC 1.3.1.122: (S)-8-oxocitronellyl enol synthase EC 1.3.1.123: 8-oxogeranial reductase EC 1.3.1.124: 2,4-dienoyl-CoA reductase [(3E)-enoyl-CoA-producing]
Sources: en.wikipedia.org
GDPbio: GDPbio (Genome based prediction of Diseases and Personal medicines using Bioinformatics) is a project focused on providing various resources related to genome analysis, particularly for the prediction of disease susceptibility of individuals and personalized medicine development, with the aim of public health improvement. AminoFAST: Functional Annotation Tools for Amino Acids (AminoFAST) is a server designed to serve the bioinformatics community. Its aim is to develop as many tools as possible to understand the function of amino acids in proteins based on protein structure in PDB. The broad knowledge of protein function would help in the identification of novel drug targets.
Turin is in northwest Italy. It is surrounded on the western and northern front by the Alps and on the eastern front by a high hill that is the natural continuation of the hills of Monferrato. Four major rivers pass through the city: the Po and three of its tributaries, the River Dora Riparia (once known as Duria Minor by the Romans, from the Celtic noun duria, 'water'), the Stura di Lanzo and the Sangone.
=== 30 December === The Ukrainian army claimed to have shot down 16 drones launched by Russian forces at Kyiv and other cities. The Mayor of Kyiv, Vitali Klitschko, stated that two were shot down outside Kyiv while five were shot down "over" Kyiv. President Putin and Chinese President Xi Jinping held talks via video link in which the latter reassured the former that he would maintain an "objective and fair stance" regarding the situation, according to CCTV.
Sources: en.wikipedia.org
Chromatographic methods can separate the two forms before detection. Enzymatic assays often measure total glutathione first and then use a separate procedure to estimate the oxidized fraction. The difference between total and oxidized amounts provides an indirect estimate of the reduced form.
Acidification lowers pH and slows thiol oxidation during handling. It also helps precipitate proteins that could interfere with detection. Typical choices include metaphosphoric acid and sulfosalicylic acid.
Dissolved oxygen reacts with the thiol group, forming glutathione disulfide. Neutral and alkaline conditions generally increase the oxidation rate. Light, metal ions, and repeated freezing and thawing can also reduce stability.
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.