This is a working overview of HPLC, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
Because GSH is central to redox balance, its status is studied in aging, liver disease, neurodegenerative conditions, and metabolic disorders. Observational studies often report lower GSH or higher GSSG in affected tissues, but such associations do not establish that raising glutathione changes disease outcomes. Oral glutathione is digested into amino acids, and whether intact absorption occurs remains debated; precursors such as N-acetylcysteine and cysteine donors are also investigated. Regulatory agencies generally treat glutathione as a dietary supplement, not an approved drug, and clinical claims require evidence from controlled trials.
Glutathione is a small tripeptide composed of glutamate, cysteine, and glycine, with the unusual gamma-glutamyl linkage between glutamate and cysteine. Its cysteine thiol group makes it a major non-enzymatic antioxidant in cells. The reduced form, GSH, predominates in most intracellular compartments, while the oxidized disulfide form, GSSG, is produced when GSH reduces reactive oxygen species. Intracellular concentrations often reach millimolar levels, whereas plasma concentrations are much lower, typically in the low micromolar range. This gradient reflects active synthesis, transport, and consumption rather than passive distribution.
Synthesis occurs in two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine to complete the tripeptide. The pathway is feedback-inhibited by GSH and limited by cysteine availability, so cysteine supply often constrains production. Once formed, GSH participates in redox buffering, xenobiotic conjugation, and protein glutathionylation. Glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid peroxides, yielding GSSG, while glutathione reductase regenerates GSH using NADPH. Glutathione S-transferases conjugate electrophiles to GSH, supporting detoxification and excretion.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C10H17N3O6S | Tripeptide of glutamate, cysteine, and glycine. |
| Molar mass | 307.32 g/mol | Calculated from the molecular formula. |
| Appearance | White to off-white powder | Typically crystalline or lyophilized solid. |
| Solubility | Soluble in water; insoluble in ethanol | Aqueous solutions are acidic and prone to oxidation. |
| Typical storage | -20 °C, desiccated, protect from light | Reduce exposure to oxygen and moisture. |
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.
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.
Stability depends on pH, temperature, oxygen exposure, and trace metals. Aqueous solutions of reduced glutathione are susceptible to oxidation, especially when neutral or alkaline and exposed to air. Transition metal ions can catalyze thiol oxidation, so chelators and inert atmospheres are sometimes used in research settings. Standards are typically stored cold and desiccated, with limited freeze-thaw cycles. Questions remain about how closely in vitro stability data reflect the behavior of glutathione within intact cells and tissues.
Measuring glutathione requires attention to oxidation during sample handling, because GSH in biological samples can convert to GSSG or form mixed disulfides with proteins after collection. Acidic extraction, rapid cooling, and chelating agents are commonly used to limit such changes. Analytical methods usually distinguish free reduced glutathione, total glutathione, and protein-bound forms. Because these forms have different stability and reactivity, reported values depend heavily on the preparation protocol. No single preparation is universally suitable for every biological matrix or analytical goal.
Now EC 1.1.1.303, diacetyl reductase [(R)-acetoin forming] and EC 1.1.1.304, diacetyl reductase [(S)-acetoin forming] EC 1.1.1.6: glycerol dehydrogenase EC 1.1.1.7: propanediol-phosphate dehydrogenase EC 1.1.1.8: glycerol-3-phosphate dehydrogenase (NAD+) EC 1.1.1.9: D-xylulose reductase EC 1.1.1.10: L-xylulose reductase EC 1.1.1.11: D-arabinitol 4-dehydrogenase EC 1.1.1.12: L-arabinitol 4-dehydrogenase EC 1.1.1.13: L-arabinitol 2-dehydrogenase EC 1.1.1.14: L-iditol 2-dehydrogenase EC 1.1.1.15: D-iditol 2-dehydrogenase EC 1.1.1.16: galactitol 2-dehydrogenase EC 1.1.1.17: mannitol-1-phosphate 5-dehydrogenase EC 1.1.1.18: inositol 2-dehydrogenase EC 1.1.1.19: glucuronate reductase EC 1.1.1.20: glucuronolactone reductase EC 1.1.1.207: (-)-menthol dehydrogenase EC 1.1.1.208: (+)-neomenthol dehydrogenase EC 1.1.1.21: aldose reductase EC 1.1.1.22: UDP-glucose 6-dehydrogenase EC 1.1.1.222: (R)-4-hydroxyphenyllactate dehydrogenase EC 1.1.1.23: histidinol dehydrogenase| EC 1.1.1.24: quinate/shikimate dehydrogenase (NAD+) EC 1.1.1.25: shikimate dehydrogenase (NADP+) EC 1.1.1.26: glyoxylate reductase EC 1.1.1.27: L-lactate dehydrogenase EC 1.1.1.28: D-lactate dehydrogenase EC 1.1.1.29: glycerate dehydrogenase EC 1.1.1.30: 3-hydroxybutyrate dehydrogenase EC 1.1.1.31: 3-hydroxyisobutyrate dehydrogenase EC 1.1.1.32: mevaldate reductase EC 1.1.1.33: mevaldate reductase (NADPH) EC 1.1.1.34: hydroxymethylglutaryl-CoA reductase (NADPH) EC 1.1.1.35: 3-hydroxyacyl-CoA dehydrogenase EC 1.1.1.36: acetoacetyl-CoA reductase EC 1.1.1.37: malate dehydrogenase EC 1.1.1.38: malate dehydrogenase (oxaloacetate-decarboxylating) EC 1.1.1.39: malate dehydrogenase (decarboxylating) EC 1.1.1.40: malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) EC 1.1.1.41: isocitrate dehydrogenase (NAD+) EC 1.1.1.42: isocitrate dehydrogenase (NADP+) EC 1.1.1.43: phosphogluconate 2-dehydrogenase EC 1.1.1.44: phosphogluconate dehydrogenase (NADP+-dependent, decarboxylating) EC 1.1.1.45: L-gulonate 3-dehydrogenase EC 1.1.1.46: L-arabinose 1-dehydrogenase EC 1.1.1.47: glucose 1-dehydrogenase [NAD(P)+)] EC 1.1.1.48: D-galactose 1-dehydrogenase EC 1.1.1.49: glucose-6-phosphate dehydrogenase (NADP+) EC 1.1.1.50: 3α-hydroxysteroid 3-dehydrogenase (Si-specific) EC 1.1.1.51: 3(or 17)β-hydroxysteroid dehydrogenase EC 1.1.1.52: 3α-hydroxycholanate dehydrogenase (NAD+) EC 1.1.1.53: 3α(or 20β)-hydroxysteroid dehydrogenase EC 1.1.1.54: allyl-alcohol dehydrogenase EC 1.1.1.55: lactaldehyde reductase (NADPH) EC 1.1.1.56: ribitol 2-dehydrogenase EC 1.1.1.57: fructuronate reductase EC 1.1.1.58: tagaturonate reductase EC 1.1.1.59: 3-hydroxypropionate dehydrogenase EC 1.1.1.60: 2-hydroxy-3-oxopropionate reductase EC 1.1.1.61: 4-hydroxybutyrate dehydrogenase EC 1.1.1.62: 17β-estradiol 17-dehydrogenase EC 1.1.1.63: testosterone 17β-dehydrogenase. Now EC 1.1.1.239, 3α(17β)-hydroxysteroid dehydrogenase (NAD+) EC 1.1.1.64: testosterone 17β-dehydrogenase (NADP+) EC 1.1.1.65: pyridoxine 4-dehydrogenase EC 1.1.1.66: ω-hydroxydecanoate dehydrogenase EC 1.1.1.67: mannitol 2-dehydrogenase EC 1.1.1.68: 5,10-methylenetetrahydrofolate reductase. Now EC 1.5.1.20, methylenetetrahydrofolate reductase [NAD(P)H] EC 1.1.1.69: gluconate 5-dehydrogenase EC 1.1.1.70: D-glucuronolactone dehydrogenase. Now included with EC 1.2.1.3 aldehyde dehydrogenase (NAD+) EC 1.1.1.71: alcohol dehydrogenase [NAD(P)+] EC 1.1.1.72: glycerol dehydrogenase (NADP+) EC 1.1.1.73: octanol dehydrogenase EC 1.1.1.74: D-aminopropanol dehydrogenase (reaction due to EC 1.1.1.4 (R,R)-butanediol dehydrogenase) EC 1.1.1.75: (R)-aminopropanol dehydrogenase EC 1.1.1.76: (S,S)-butanediol dehydrogenase EC 1.1.1.77: lactaldehyde reductase EC 1.1.1.78: methylglyoxal reductase (NADH-dependent) EC 1.1.1.79: glyoxylate reductase (NADP+) EC 1.1.1.80: isopropanol dehydrogenase (NADP+) EC 1.1.1.81: hydroxypyruvate reductase EC 1.1.1.82: malate dehydrogenase (NADP+) EC 1.1.1.83: D-malate dehydrogenase (decarboxylating) EC 1.1.1.84: dimethylmalate dehydrogenase EC 1.1.1.85: 3-isopropylmalate dehydrogenase EC 1.1.1.86: ketol-acid reductoisomerase (NADP+) EC 1.1.1.87: homoisocitrate dehydrogenase EC 1.1.1.88: hydroxymethylglutaryl-CoA reductase EC 1.1.1.89: dihydroxyisovalerate dehydrogenase (isomerizing). Now included with EC 1.1.1.86 ketol-acid reductoisomerase EC 1.1.1.90: aryl-alcohol dehydrogenase EC 1.1.1.91: aryl-alcohol dehydrogenase (NADP+) EC 1.1.1.92: oxaloglycolate reductase (decarboxylating) EC 1.1.1.93: tartrate dehydrogenase EC 1.1.1.94: glycerol-3-phosphate dehydrogenase [NAD(P)+] EC 1.1.1.95: phosphoglycerate dehydrogenase EC 1.1.1.96: diiodophenylpyruvate reductase EC 1.1.1.97: 3-hydroxybenzyl-alcohol dehydrogenase EC 1.1.1.98: (R)-2-hydroxy-fatty-acid dehydrogenase EC 1.1.1.99: (S)-2-hydroxy-fatty-acid dehydrogenase EC 1.1.1.100: 3-oxoacyl-[acyl-carrier-protein] reductase EC 1.1.1.101: acylglycerone-phosphate reductase EC 1.1.1.102: 3-dehydrosphinganine reductase EC 1.1.1.103: L-threonine 3-dehydrogenase EC 1.1.1.104: 4-oxoproline reductase EC 1.1.1.105: all-trans-retinol dehydrogenase (NAD+) EC 1.1.1.106: pantoate 4-dehydrogenase EC 1.1.1.107: pyridoxal 4-dehydrogenase EC 1.1.1.108: carnitine 3-dehydrogenase EC 1.1.1.109: Now EC 1.3.1.28, 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase EC 1.1.1.110: aromatic 2-oxoacid reductase EC 1.1.1.111: 3-(imidazol-5-yl)lactate dehydrogenase EC 1.1.1.112: indanol dehydrogenase EC 1.1.1.113: L-xylose 1-dehydrogenase EC 1.1.1.114: apiose 1-reductase EC 1.1.1.115: ribose 1-dehydrogenase (NADP+) EC 1.1.1.116: D-arabinose 1-dehydrogenase (NAD+) EC 1.1.1.117: D-arabinose 1-dehydrogenase [NAD(P)+] EC 1.1.1.118: glucose 1-dehydrogenase (NAD+) EC 1.1.1.119: glucose 1-dehydrogenase (NADP+) EC 1.1.1.120: galactose 1-dehydrogenase (NADP+) EC 1.1.1.121: aldose 1-dehydrogenase (NAD+) EC 1.1.1.122: D-threo-aldose 1-dehydrogenase EC 1.1.1.123: sorbose 5-dehydrogenase (NADP+) EC 1.1.1.124: fructose 5-dehydrogenase (NADP+) EC 1.1.1.125: 2-deoxy-D-gluconate 3-dehydrogenase EC 1.1.1.126: 2-dehydro-3-deoxy-D-gluconate 6-dehydrogenase EC 1.1.1.127: 2-dehydro-3-deoxy-D-gluconate 5-dehydrogenase EC 1.1.1.128: The reaction described is covered by EC 1.1.1.264, L-idonate 5-dehydrogenase. EC 1.1.1.129: L-threonate 3-dehydrogenase EC 1.1.1.130: 3-dehydro-L-gulonate 2-dehydrogenase EC 1.1.1.131: mannuronate reductase EC 1.1.1.132: GDP-mannose 6-dehydrogenase EC 1.1.1.133: dTDP-4-dehydrorhamnose reductase EC 1.1.1.134: dTDP-6-deoxy-L-talose 4-dehydrogenase (NADP+) EC 1.1.1.135: GDP-6-deoxy-D-talose 4-dehydrogenase EC 1.1.1.136: UDP-N-acetylglucosamine 6-dehydrogenase EC 1.1.1.137: ribitol-5-phosphate 2-dehydrogenase EC 1.1.1.138: mannitol 2-dehydrogenase (NADP+) EC 1.1.1.139: polyol dehydrogenase (NADP+). Now included with EC 1.1.1.21 aldehyde reductase EC 1.1.1.140: sorbitol-6-phosphate 2-dehydrogenase EC 1.1.1.141: 15-hydroxyprostaglandin dehydrogenase (NAD+) EC 1.1.1.142: D-pinitol dehydrogenase EC 1.1.1.143: sequoyitol dehydrogenase EC 1.1.1.144: perillyl-alcohol dehydrogenase EC 1.1.1.145: 3β-hydroxy-Δ5-steroid dehydrogenase EC 1.1.1.146: 11β-hydroxysteroid dehydrogenase EC 1.1.1.147: 16α-hydroxysteroid dehydrogenase EC 1.1.1.148: estradiol 17α-dehydrogenase EC 1.1.1.149: 20α-hydroxysteroid dehydrogenase EC 1.1.1.150: 21-hydroxysteroid dehydrogenase (NAD+) EC 1.1.1.151: 21-hydroxysteroid dehydrogenase (NADP+) EC 1.1.1.152: 3α-hydroxy-5β-androstane-17-one 3α-dehydrogenase EC 1.1.1.153: sepiapterin reductase (L-erythro-7,8-dihydrobiopterin forming) EC 1.1.1.154: ureidoglycolate dehydrogenase EC 1.1.1.155: homoisocitrate dehydrogenase. The enzyme is identical to EC 1.1.1.87, homoisocitrate dehydrogenase EC 1.1.1.156: glycerol 2-dehydrogenase (NADP+) EC 1.1.1.157: 3-hydroxybutyryl-CoA dehydrogenase EC 1.1.1.158: Now EC 1.3.1.98, UDP-N-acetylmuramate dehydrogenase EC 1.1.1.159: 7α-hydroxysteroid dehydrogenase EC 1.1.1.160: dihydrobunolol dehydrogenase EC 1.1.1.161: The activity is part of EC 1.14.13.15, cholestanetriol 26-monooxygenase EC 1.1.1.162: erythrulose reductase EC 1.1.1.163: cyclopentanol dehydrogenase EC 1.1.1.164: hexadecanol dehydrogenase EC 1.1.1.165: 2-alkyn-1-ol dehydrogenase EC 1.1.1.166: hydroxycyclohexanecarboxylate dehydrogenase EC 1.1.1.167: hydroxymalonate dehydrogenase EC 1.1.1.168: 2-dehydropantolactone reductase (Re-specific) EC 1.1.1.169: 2-dehydropantoate 2-reductase EC 1.1.1.170: 3β-hydroxysteroid-4α-carboxylate 3-dehydrogenase (decarboxylating) EC 1.1.1.171: Now EC 1.5.1.20, methylenetetrahydrofolate reductase [NAD(P)H] EC 1.1.1.172: 2-oxoadipate reductase EC 1.1.1.173: L-rhamnose 1-dehydrogenase EC 1.1.1.174: cyclohexane-1,2-diol dehydrogenase EC 1.1.1.175: D-xylose 1-dehydrogenase EC 1.1.1.176: 12α-hydroxysteroid dehydrogenase EC 1.1.1.177: glycerol-3-phosphate 1-dehydrogenase (NADP+) EC 1.1.1.178: 3-hydroxy-2-methylbutyryl-CoA dehydrogenase EC 1.1.1.179: D-xylose 1-dehydrogenase (NADP+, D-xylono-1,5-lactone-forming) EC 1.1.1.180: Now included with EC 1.1.1.131 mannuronate reductase EC 1.1.1.181: cholest-5-ene-3β,7α-diol 3β-dehydrogenase EC 1.1.1.182: Now included with EC 1.1.1.198 (+)-borneol dehydrogenase, EC 1.1.1.227 (-)-borneol dehydrogenase and EC 1.1.1.228 (+)-sabinol dehydrogenase EC 1.1.1.183: geraniol dehydrogenase (NADP+) EC 1.1.1.184: carbonyl reductase (NADPH) EC 1.1.1.185: L-glycol dehydrogenase EC 1.1.1.186: dTDP-galactose 6-dehydrogenase EC 1.1.1.187: GDP-4-dehydro-D-rhamnose reductase EC 1.1.1.188: prostaglandin-F synthase EC 1.1.1.189: prostaglandin-E2 9-reductase EC 1.1.1.190: indole-3-acetaldehyde reductase (NADH) EC 1.1.1.191: indole-3-acetaldehyde reductase (NADPH) EC 1.1.1.192: long-chain-alcohol dehydrogenase EC 1.1.1.193: 5-amino-6-(5-phosphoribosylamino)uracil reductase EC 1.1.1.194: coniferyl-alcohol dehydrogenase EC 1.1.1.195: cinnamyl-alcohol dehydrogenase EC 1.1.1.196: 15-hydroxyprostaglandin-D dehydrogenase (NADP+) EC 1.1.1.197: 15-hydroxyprostaglandin dehydrogenase (NADP+) EC 1.1.1.198: (+)-borneol dehydrogenase EC 1.1.1.199: (S)-usnate reductase EC 1.1.1.200: aldose-6-phosphate reductase (NADPH) EC 1.1.1.228: (+)-sabinol dehydrogenase EC 1.1.1.251: galactitol-1-phosphate 5-dehydrogenase EC 1.1.1.252: tetrahydroxynaphthalene reductase EC 1.1.1.253: Now EC 1.5.1.33, pteridine reductase EC 1.1.1.254: (S)-carnitine 3-dehydrogenase EC 1.1.1.255: mannitol dehydrogenase EC 1.1.1.256: fluoren-9-ol dehydrogenase EC 1.1.1.257: 4-(hydroxymethyl)benzenesulfonate dehydrogenase EC 1.1.1.258: 6-hydroxyhexanoate dehydrogenase EC 1.1.1.259: 3-hydroxypimeloyl-CoA dehydrogenase EC 1.1.1.260: sulcatone reductase EC 1.1.1.261: sn-glycerol-1-phosphate dehydrogenase EC 1.1.1.262: 4-hydroxythreonine-4-phosphate dehydrogenase EC 1.1.1.263: 1,5-anhydro-D-fructose reductase EC 1.1.1.264: L-idonate 5-dehydrogenase EC 1.1.1.265: 3-methylbutanal reductase EC 1.1.1.266: dTDP-4-dehydro-6-deoxyglucose reductase EC 1.1.1.267: 1-deoxy-D-xylulose-5-phosphate reductoisomerase EC 1.1.1.268: 2-(R)-hydroxypropyl-CoM dehydrogenase EC 1.1.1.269: 2-(S)-hydroxypropyl-CoM dehydrogenase EC 1.1.1.270: 3β-hydroxysteroid 3-dehydrogenase EC 1.1.1.271: GDP-L-fucose synthase EC 1.1.1.272: D-2-hydroxyacid dehydrogenase (NADP+) EC 1.1.1.273: vellosimine dehydrogenase EC 1.1.1.274: 2,5-didehydrogluconate reductase (2-dehydro-D-gluconate-forming) EC 1.1.1.275: (+)-trans-carveol dehydrogenase EC 1.1.1.276: serine 3-dehydrogenase (NADP+) EC 1.1.1.277: 3β-hydroxy-5β-steroid dehydrogenase EC 1.1.1.278: 3β-hydroxy-5α-steroid dehydrogenase EC 1.1.1.279: (R)-3-hydroxyacid-ester dehydrogenase EC 1.1.1.280: (S)-3-hydroxyacid-ester dehydrogenase EC 1.1.1.281: GDP-4-dehydro-6-deoxy-D-mannose reductase EC 1.1.1.282: Quinate/shikimate dehydrogenase EC 1.1.1.283: methylglyoxal reductase (NADPH-dependent) EC 1.1.1.284: S-(hydroxymethyl)glutathione dehydrogenase EC 1.1.1.285: 3′′-deamino-3′′-oxonicotianamine reductase EC 1.1.1.286: isocitrate—homoisocitrate dehydrogenase EC 1.1.1.287: D-arabinitol dehydrogenase (NADP+) EC 1.1.1.288: xanthoxin dehydrogenase EC 1.1.1.289: sorbose reductase EC 1.1.1.290: 4-phosphoerythronate dehydrogenase EC 1.1.1.291: 2-hydroxymethylglutarate dehydrogenase EC 1.1.1.292: 1,5-anhydro-D-fructose reductase (1,5-anhydro-D-mannitol-forming) EC 1.1.1.293: tropinone reductase I. This enzyme was already in the Enzyme List as EC 1.1.1.206, tropine dehydrogenase so EC 1.1.1.293 has been withdrawn at the public-review stage EC 1.1.1.294: chlorophyll(ide) b reductase EC 1.1.1.295: momilactone-A synthase EC 1.1.1.296: dihydrocarveol dehydrogenase EC 1.1.1.297: limonene-1,2-diol dehydrogenase EC 1.1.1.298: 3-hydroxypropionate dehydrogenase (NADP+) EC 1.1.1.299: malate dehydrogenase [NAD(P)+)] EC 1.1.1.300: NADP-retinol dehydrogenase EC 1.1.1.301: D-arabitol-phosphate dehydrogenase EC 1.1.1.302: 2,5-diamino-6-(ribosylamino)-4(3H)-pyrimidinone 5′-phosphate reductase EC 1.1.1.303: Diacetyl reductase ((R)-acetoin forming) EC 1.1.1.304: Diacetyl reductase ((S)-acetoin forming) EC 1.1.1.305: UDP-glucuronic acid dehydrogenase (UDP-4-keto-hexauronic acid decarboxylating) EC 1.1.1.306: S-(hydroxymethyl)mycothiol dehydrogenase EC 1.1.1.307: D-xylose reductase EC 1.1.1.308: sulfopropanediol 3-dehydrogenase EC 1.1.1.309: phosphonoacetaldehyde reductase (NADH) EC 1.1.1.310: (S)-sulfolactate dehydrogenase EC 1.1.1.311: (S)-1-phenylethanol dehydrogenase EC 1.1.1.312: 2-hydroxy-4-carboxymuconate semialdehyde hemiacetal dehydrogenase EC 1.1.1.313: sulfoacetaldehyde reductase EC 1.1.1.314: Now known to be catalyzed by EC 1.14.14.95, germacrene A hydroxylase EC 1.1.1.315: 11-cis-retinol dehydrogenase EC 1.1.1.316: L-galactose 1-dehydrogenase EC 1.1.1.317: perakine reductase EC 1.1.1.318: eugenol synthase EC 1.1.1.319: isoeugenol synthase EC 1.1.1.320: benzil reductase [(S)-benzoin forming] EC 1.1.1.321: benzil reductase [(R)-benzoin forming] EC 1.1.1.322: (–)-endo-fenchol dehydrogenase EC 1.1.1.323: (+)-thujan-3-ol dehydrogenase EC 1.1.1.324: 8-hydroxygeraniol dehydrogenase EC 1.1.1.325: sepiapterin reductase (L-threo-7,8-dihydrobiopterin forming) EC 1.1.1.326: zerumbone synthase EC 1.1.1.327: 5-exo-hydroxycamphor dehydrogenase EC 1.1.1.328: nicotine blue oxidoreductase EC 1.1.1.329: 2-deoxy-scyllo-inosamine dehydrogenase EC 1.1.1.330: very-long-chain 3-oxoacyl-CoA reductase EC 1.1.1.331: secoisolariciresinol dehydrogenase EC 1.1.1.332: chanoclavine-I dehydrogenase EC 1.1.1.333: decaprenylphospho-β-D-erythro-pentofuranosid-2-ulose 2-reductase EC 1.1.1.334: methylecgonone reductase EC 1.1.1.335: UDP-N-acetyl-2-amino-2-deoxyglucuronate dehydrogenase EC 1.1.1.336: UDP-N-acetyl-D-mannosamine dehydrogenase EC 1.1.1.337: L-2-hydroxycarboxylate dehydrogenase (NAD+) EC 1.1.1.338: (2R)-3-sulfolactate dehydrogenase (NADP+) EC 1.1.1.339: dTDP-6-deoxy-L-talose 4-dehydrogenase (NAD+) EC 1.1.1.340: 1-deoxy-11β-hydroxypentalenate dehydrogenase EC 1.1.1.341: CDP-abequose synthase EC 1.1.1.342: CDP-paratose synthase EC 1.1.1.343: phosphogluconate dehydrogenase (NAD+-dependent, decarboxylating) EC 1.1.1.344: dTDP-6-deoxy-L-talose 4-dehydrogenase [NAD(P)+] EC 1.1.1.345: D-2-hydroxyacid dehydrogenase (NAD+) EC 1.1.1.346: 2,5-didehydrogluconate reductase (2-dehydro-L-gulonate-forming) EC 1.1.1.347: geraniol dehydrogenase (NAD+) EC 1.1.1.348: (3R)-2′-hydroxyisoflavanone reductase EC 1.1.1.349: norsolorinic acid ketoreductase EC 1.1.1.350: ureidoglycolate dehydrogenase (NAD+) EC 1.1.1.351: phosphogluconate dehydrogenase [NAD(P)+-dependent, decarboxylating] EC 1.1.1.352: 5′-hydroxyaverantin dehydrogenase EC 1.1.1.353: versiconal hemiacetal acetate reductase EC 1.1.1.354: farnesol dehydrogenase (NAD+) EC 1.1.1.355: 2′-dehydrokanamycin reductase EC 1.1.1.356: GDP-L-colitose synthase EC 1.1.1.357: 3α-hydroxysteroid 3-dehydrogenase EC 1.1.1.358: 2-dehydropantolactone reductase EC 1.1.1.359: aldose 1-dehydrogenase [NAD(P)+] EC 1.1.1.360: glucose/galactose 1-dehydrogenase EC 1.1.1.361: glucose-6-phosphate 3-dehydrogenase EC 1.1.1.362: aklaviketone reductase EC 1.1.1.363: glucose-6-phosphate dehydrogenase [NAD(P)+] EC 1.1.1.364: dTDP-4-dehydro-6-deoxy-α-D-gulose 4-ketoreductase EC 1.1.1.365: D-galacturonate reductase EC 1.1.1.366: L-idonate 5-dehydrogenase (NAD+) EC 1.1.1.367: UDP-2-acetamido-2,6-β-L-arabino-hexul-4-ose reductase EC 1.1.1.368: 6-hydroxycyclohex-1-ene-1-carbonyl-CoA dehydrogenase EC 1.1.1.369: D-chiro-inositol 1-dehydrogenase EC 1.1.1.370: scyllo-inositol 2-dehydrogenase (NAD+) EC 1.1.1.371: scyllo-inositol 2-dehydrogenase (NADP+) EC 1.1.1.372: D/L-glyceraldehyde reductase EC 1.1.1.373: sulfolactaldehyde 3-reductase EC 1.1.1.374: UDP-N-acetylglucosamine 3-dehydrogenase EC 1.1.1.375: L-2-hydroxycarboxylate dehydrogenase [NAD(P)+] EC 1.1.1.376: L-arabinose 1-dehydrogenase [NAD(P)+] EC 1.1.1.377: L-rhamnose 1-dehydrogenase (NADP+) EC 1.1.1.378: L-rhamnose 1-dehydrogenase [NAD(P)+] EC 1.1.1.379: (R)-mandelate dehydrogenase EC 1.1.1.380: L-gulonate 5-dehydrogenase EC 1.1.1.381: 3-hydroxy acid dehydrogenase EC 1.1.1.382: ketol-acid reductoisomerase (NAD+) EC 1.1.1.383: ketol-acid reductoisomerase [NAD(P)+] EC 1.1.1.384: dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose 3-reductase EC 1.1.1.385: dihydroanticapsin dehydrogenase EC 1.1.1.386: ipsdienol dehydrogenase EC 1.1.1.387: L-serine 3-dehydrogenase (NAD+) EC 1.1.1.388: glucose-6-phosphate dehydrogenase (NAD+) EC 1.1.1.389: 2-dehydro-3-deoxy-L-galactonate 5-dehydrogenase EC 1.1.1.390: sulfoquinovose 1-dehydrogenase EC 1.1.1.391: 3β-hydroxycholanate 3-dehydrogenase (NAD+) EC 1.1.1.392: 3α-hydroxycholanate dehydrogenase (NADP+) EC 1.1.1.393: 3β-hydroxycholanate 3-dehydrogenase (NADP+) EC 1.1.1.394: aurachin B dehydrogenase EC 1.1.1.395: 3α-hydroxy bile acid-CoA-ester 3-dehydrogenase EC 1.1.1.396: bacteriochlorophyllide a dehydrogenase EC 1.1.1.397: β-methylindole-3-pyruvate reductase EC 1.1.1.398: 2-glutathionyl-2-methylbut-3-en-1-ol dehydrogenase EC 1.1.1.399: 2-oxoglutarate reductase EC 1.1.1.400: 2-methyl-1,2-propanediol dehydrogenase EC 1.1.1.401: 2-dehydro-3-deoxy-L-rhamnonate dehydrogenase (NAD+) EC 1.1.1.402: D-erythritol 1-phosphate dehydrogenase EC 1.1.1.403: D-threitol dehydrogenase (NAD+) EC 1.1.1.404: tetrachlorobenzoquinone reductase EC 1.1.1.405: ribitol-5-phosphate 2-dehydrogenase (NADP+) EC 1.1.1.406: galactitol 2-dehydrogenase (L-tagatose-forming) EC 1.1.1.407: D-altritol 5-dehydrogenase EC 1.1.1.408: 4-phospho-D-threonate 3-dehydrogenase EC 1.1.1.409: 4-phospho-D-erythronate 3-dehydrogenase EC 1.1.1.410: D-erythronate 2-dehydrogenase EC 1.1.1.411: L-threonate 2-dehydrogenase EC 1.1.1.412: 2-alkyl-3-oxoalkanoate reductase EC 1.1.1.413: A-factor type γ-butyrolactone 1′-reductase (1S-forming) EC 1.1.1.414: L-galactonate 5-dehydrogenase EC 1.1.1.415: noscapine synthase EC 1.1.1.416: isopyridoxal dehydrogenase (5-pyridoxolactone-forming) EC 1.1.1.417: 3β-hydroxysteroid-4β-carboxylate 3-dehydrogenase (decarboxylating) EC 1.1.1.418: plant 3β-hydroxysteroid-4α-carboxylate 3-dehydrogenase (decarboxylating) EC 1.1.1.419: nepetalactol dehydrogenase EC 1.1.1.420: D-apiose dehydrogenase EC 1.1.1.421: D-apionate oxidoisomerase EC 1.1.1.422: pseudoephedrine dehydrogenase EC 1.1.1.423: (1R,2S)-ephedrine 1-dehydrogenase EC 1.1.1.424: D-xylose 1-dehydrogenase (NADP+, D-xylono-1,4-lactone-forming) EC 1.1.1.425: levoglucosan dehydrogenase EC 1.1.1.426: UDP-N-acetyl-α-D-quinovosamine dehydrogenase
In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms used to describe ratios of how much of a reactant has reacted—conversion, how much of a desired product was formed—yield, and how much desired product was formed in ratio to the undesired product—selectivity, represented as X, S, and Y. According to the Elements of Chemical Reaction Engineering manual, yield refers to the amount of a specific product formed per mole of reactant consumed. In chemistry, mole is used to describe quantities of reactants and products in chemical reactions. The Compendium of Chemical Terminology defined yield as the "ratio expressing the efficiency of a mass conversion process. The yield coefficient is defined as the amount of cell mass (kg) or product formed (kg,mol) related to the consumed substrate (carbon or nitrogen source or oxygen in kg or moles) or to the intracellular ATP production (moles)." In the section "Calculations of yields in the monitoring of reactions" in the 1996 4th edition of Vogel's Textbook of Practical Organic Chemistry (1978), the authors write that, "theoretical yield in an organic reaction is the weight of product which would be obtained if the reaction has proceeded to completion according to the chemical equation. The yield is the weight of the pure product which is isolated from the reaction." In 'the 1996 edition of Vogel's Textbook, percentage yield is expressed as,
== Awards == 2014 – Akabori Memorial Award (Japanese Peptide Society) 2016 – Max Bergmann Gold Medal (German Peptide Society) 2016 – Nippon Venture Award (METI) 2017 – Nagoya Silver Medal of Organic Chemistry (MSD Life Science Foundation) 2019 – Vincent du Vigneaud Award (American Peptide Society) 2020 – Humboldt Prize (Humboldt Foundation) 2020 – World Entrepreneur of the Year, Japan (EY) 2022 – Prelog Medal (ETH Zurich) 2023 – Wolf Prize in Chemistry (Wolf Foundation) 2024 – Asian Scientist 100 (Asian Scientist) 2026 – Elected a Fellow of the Royal Society
In biochemistry, lipogenesis is the conversion of fatty acids and glycerol into fats, or a metabolic process through which acetyl-CoA is converted to triglyceride for storage in fat. Lipogenesis encompasses both fatty acid and triglyceride synthesis, with the latter being the process by which fatty acids are esterified to glycerol before being packaged into very-low-density lipoprotein (VLDL). Fatty acids are produced in the cytoplasm of cells by repeatedly adding two-carbon units to acetyl-CoA. Triacylglycerol synthesis, on the other hand, occurs in the endoplasmic reticulum membrane of cells by bonding three fatty acid molecules to a glycerol molecule. Both processes take place mainly in liver and adipose tissue. Nevertheless, it also occurs to some extent in other tissues such as the gut and kidney. After being packaged into VLDL in the liver, the resulting lipoprotein is then secreted directly into the blood for delivery to peripheral tissues.
People in ancient East Asia ate tea for centuries, perhaps even millennia, before ever consuming it as a beverage. They would nibble on the leaves raw, add them to soups or greens, or ferment them and chew them as areca nut is chewed. Tea drinking may have begun in the region of Yunnan, where it was used for medicinal purposes. It is believed that in Sichuan, "people began to boil tea leaves for consumption into a concentrated liquid without the addition of other leaves or herbs, thereby using tea as a bitter yet stimulating drink, rather than as a medicinal concoction." Chinese legends attribute the invention of tea to the mythical Shennong (in central and northern China) in 2737 BC, although evidence suggests that tea drinking may have been introduced from southwest China. The earliest written records of tea come from China. The word tú 荼 appears in the Shijing and other ancient texts to signify a kind of "bitter vegetable" (苦菜), and it is possible that it referred to many different plants such as sow thistle, chicory, or smartweed, as well as tea. In the Chronicles of Huayang, it was recorded that the Ba people in Sichuan presented tu to the Zhou king. The Qin later conquered the state of Ba and its neighbour Shu, and according to the 17th-century scholar Gu Yanwu who wrote in Ri Zhi Lu (日知錄): "It was after the Qin had taken Shu that they learned how to drink tea." Another possible early reference to tea is found in a letter written by the Qin dynasty general Liu Kun who requested that some "real tea" to be sent to him.
Sources: en.wikipedia.org
=== Other === In April 2017 MGX Minerals reported it had received independent confirmation of its rapid lithium extraction process to recover lithium and other valuable minerals from oil and gas wastewater brine.
This is important because polysaccharide vaccines elicit antibody responses without T cell help, and as a result, those antibody responses tend to be weak and short-lived (and young children have a particularly difficult time generating these antibodies for developmental reasons, which is a major issue because the polysaccharides in question are present on the surfaces of pathogenic bacteria). However, attaching the polysaccharide to a carrier protein (especially an immunogenic one, such as tetanus toxoid) enables B cells that recognize the polysaccharide to get help from T cells that recognize the carrier protein's peptides. These are known as conjugate vaccines or glycoconjugates. Moreover, the processing of an antigen by an antigen-presenting cell causes loss of the tertiary structure of the protein, meaning that T cells recognize linear epitopes only (the amino acids recognized have to be next to each other in the primary structure). There are also subsets of T cells known as unconventional T cells that may recognize non-peptide antigens, or peptides. Many of these subsets show predominantly innate, rather than adaptive, functions.
Mahathir also strengthened political and economic cooperation with China, whilst maintaining diplomatic ambivalence on security issues to avoid escalating territorial disputes in the South China Sea. He openly criticised China's involvement in Malaysia's communist insurgency, but downplayed any military threat from China after the Cold War ended. In 1985, Mahathir visited China for the first time as prime minister, where he met Chinese leader Deng Xiaoping, establishing a new level of trust that laid the foundation for Malaysia-China relations and set the stage for decades of economic and diplomatic growth. Later, he visited China again in 1993, 1994, 1996, 1999, and twice in 2001. In the early 1990s, Mahathir played a key role in engaging China with ASEAN despite South China Sea disputes, particularly in the post-Tiananmen and post-Cold War contexts, paving the way for then Chinese Foreign Minister Qian Qichen to attend the ASEAN meeting's opening ceremony in July 1991 as a guest of the Malaysian government, and eventually leading to China's upgrade to ASEAN's dialogue partner in 1996. Amidst the Asian financial crisis, Mahathir also led several large delegations to China and Russia to seek regional economic cooperation. Besides that, Mahathir also had significant interactions with Taiwan, especially during the 1980s and 1990s, when economic ties between the two sides were at their strongest despite the lack of formal diplomatic relations.
Since 2023 the European Commission Regulation 2023/915 states that processing contaminants of food though PAHs are not allowed to exceed a sum of 4 PAHs for BaP in order to protect public health. BaP is discharged in wastewater by industries such as smelters, particularly iron and steel mills and aluminium smelters.
Sources: en.wikipedia.org
GSH is the reduced, thiol-containing form of glutathione, while GSSG is the oxidized disulfide dimer formed when two GSH molecules react. Cells maintain a high GSH-to-GSSG ratio under normal conditions. A shift toward GSSG is often interpreted as oxidative stress, though sample handling can affect the measured ratio.
No. It is a tripeptide made from three amino acids: glutamate, cysteine, and glycine. The gamma-glutamyl bond is unusual and distinguishes it from typical peptide linkages.
Most ingested glutathione is broken down in the gastrointestinal tract into its constituent amino acids. Some formulations may protect it from digestion, but intact absorption and delivery to specific tissues remain uncertain. Research continues on precursors and delivery methods.
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.