For Research Use Only
Glutathione is supplied exclusively for in vitro laboratory and pre-clinical research. Not for human or veterinary use. No dosing, reconstitution, or administration guidance is provided. Purchase confirms the buyer is a qualified researcher.
Glutathione 1500mg — Reduced L-Glutathione (GSH) for Oxidative Stress, Redox Biology, and Cellular Antioxidant Research
Glutathione 1500mg is a research-grade preparation of reduced L-glutathione (GSH), the most abundant intracellular antioxidant tripeptide in mammalian cells. GSH is a tripeptide with the sequence γ-Glu-Cys-Gly (L-γ-glutamyl-L-cysteinyl-glycine), characterised by the unusual γ-peptide bond between glutamate and cysteine that renders it resistant to most cellular peptidases. GSH is synthesised de novo in virtually all mammalian cells through a two-step enzymatic process: first, γ-glutamylcysteine synthetase (GCS/GCLC) catalyses the ATP-dependent condensation of glutamate and cysteine to form γ-glutamylcysteine; then, glutathione synthetase (GSS) adds glycine to form GSH. Intracellular GSH concentrations typically range from 1–10 mM, making it the most abundant non-protein thiol in mammalian cells. Each 1500mg vial supplied by AbsoluteBioLab contains reduced L-glutathione, verified by HPLC to a minimum purity of ≥99.0%.
GSH serves multiple essential functions in cellular biology. As the primary intracellular antioxidant, GSH directly scavenges reactive oxygen species (ROS) and reactive nitrogen species (RNS), and serves as the electron donor for glutathione peroxidase (GPx)-catalysed reduction of hydrogen peroxide and lipid hydroperoxides to water and lipid alcohols. GSH also participates in the glutathione S-transferase (GST)-catalysed conjugation of electrophilic compounds and xenobiotics, facilitating their detoxification and export. In addition to its antioxidant functions, GSH regulates protein function through S-glutathionylation — the reversible formation of mixed disulphides between GSH and protein cysteine residues — a post-translational modification that protects proteins from irreversible oxidation and modulates their activity. The ratio of reduced GSH to oxidised glutathione (GSSG) — the GSH/GSSG ratio — is a widely used indicator of cellular redox status and oxidative stress.
Compound Identity Matrix
| Attribute | Value | Specification |
|---|---|---|
| Common Name | Glutathione (GSH); Reduced L-Glutathione | γ-Glu-Cys-Gly tripeptide; primary intracellular antioxidant |
| Sequence | γ-L-Glu-L-Cys-Gly | Unusual γ-peptide bond between Glu and Cys; protease-resistant |
| CAS Number | 70-18-8 | Reduced L-glutathione (GSH) |
| Molecular Formula | C10H17N3O6S | Reduced form (free thiol) |
| Molecular Weight | 307.32 Da | Reduced form (monoisotopic) |
| Physical Form | White crystalline powder | Free acid; hygroscopic; characteristic sulfurous odour |
| Quantity per Vial | 1500 mg | Research-grade preparation |
| Purity (HPLC) | ≥99.0% | HPLC with electrochemical or UV detection |
| Redox State | Reduced (GSH) | Free thiol confirmed; <2% GSSG content |
Analytical Specification & Release Testing
Every batch of Glutathione 1500mg supplied by AbsoluteBioLab is subjected to a comprehensive analytical release protocol. Purity is determined by HPLC confirming ≥99.0% purity. Redox state is confirmed by Ellman’s reagent (DTNB) assay to verify the presence of the free thiol and confirm <2% GSSG content. Molecular identity is confirmed by ESI-MS. Endotoxin content is confirmed at <1.0 EU/mg by LAL kinetic turbidimetric assay.
| Test Parameter | Method | Specification | Typical Result |
|---|---|---|---|
| Purity (HPLC) | HPLC (electrochemical/UV) | ≥99.0% | ≥99.5% |
| Redox state (Ellman’s) | DTNB thiol assay | <2% GSSG | <1% GSSG |
| Identity (ESI-MS) | Electrospray ionisation MS | ±0.1 Da of theoretical MW | Conforms |
| Endotoxin (LAL) | Kinetic turbidimetric LAL | <1.0 EU/mg | <0.5 EU/mg |
| Appearance | Visual inspection | White crystalline powder | Conforms |
Mechanism of Action — Redox Buffering, ROS Scavenging, and Cellular Antioxidant Defence
Glutathione (GSH) exerts its antioxidant effects through multiple mechanisms. As a direct ROS scavenger, GSH reacts non-enzymatically with hydroxyl radicals (·OH), singlet oxygen (¹O₂), and other highly reactive species, forming glutathione disulphide (GSSG) and water. More importantly, GSH serves as the electron donor for glutathione peroxidase (GPx)-catalysed reactions, in which GPx reduces hydrogen peroxide (H₂O₂) and lipid hydroperoxides (LOOH) to water and lipid alcohols, respectively, oxidising two molecules of GSH to GSSG in the process. GSSG is then reduced back to two molecules of GSH by glutathione reductase (GR) using NADPH as the electron donor, completing the glutathione redox cycle.
GSH also participates in the glutaredoxin (Grx) system, which catalyses the reduction of protein-glutathione mixed disulphides (protein-SSG) and protein disulphides, using GSH as the electron donor. This system is essential for the regulation of protein function through reversible S-glutathionylation — a post-translational modification that protects reactive cysteine residues from irreversible oxidation and modulates the activity of numerous signalling proteins, transcription factors, and metabolic enzymes. Key proteins regulated by S-glutathionylation include NF-κB, Akt, p53, and protein tyrosine phosphatases.
GSH is also a substrate for glutathione S-transferases (GSTs), a superfamily of enzymes that catalyse the conjugation of GSH to electrophilic compounds, xenobiotics, and reactive metabolites, facilitating their detoxification and export from cells via multidrug resistance-associated proteins (MRPs). This detoxification function makes GSH a critical component of cellular defence against chemical toxicity and drug resistance in cancer cells.
Research Applications
Glutathione is one of the most widely used compounds in oxidative stress and redox biology research. In oxidative stress research, GSH is used to investigate cellular antioxidant defence mechanisms, the consequences of GSH depletion on cell viability and function, and the role of the GSH/GSSG ratio as an indicator of cellular redox status. Standard assays include the Ellman’s reagent (DTNB) assay for total GSH and GSSG quantification, the GSH-Glo luminescence assay, and fluorescent probes (monochlorobimane, ThiolTracker Violet) for intracellular GSH imaging.
In redox signalling research, GSH is used to investigate the mechanisms of protein S-glutathionylation and its role in regulating signalling pathways. Researchers use GSH in combination with oxidants (H₂O₂, diamide) and reducing agents (DTT, TCEP) to control the redox state of proteins in cell-free and cell-based systems, and to investigate the functional consequences of S-glutathionylation on protein activity and signalling.
In cancer research, GSH is used to investigate the role of GSH metabolism in cancer cell drug resistance, as elevated GSH levels in cancer cells are associated with resistance to chemotherapy and radiotherapy. Researchers use GSH in combination with GSH-depleting agents (buthionine sulfoximine, BSO) and GST inhibitors to investigate the mechanisms of GSH-mediated drug resistance and to identify potential targets for overcoming resistance in cancer models.
Storage, Stability & Handling
| Condition | Specification | Notes |
|---|---|---|
| Long-term storage (dry powder) | −20°C | Stable for ≥24 months from manufacture date; desiccated |
| Short-term storage (dry powder) | 2–8°C | Acceptable for up to 3 months; desiccated, inert atmosphere |
| Dissolved solution | Use immediately or freeze at −80°C | GSH oxidises rapidly in solution; prepare fresh for each experiment |
| pH sensitivity | Stable at pH 3–5; unstable at neutral/alkaline pH | Dissolve in slightly acidic buffer (0.1% TFA or 10 mM HCl) for stability |
| Oxidation prevention | Inert atmosphere (N₂ or Ar) recommended | Free thiol is susceptible to air oxidation; minimise exposure to oxygen |
Frequently Asked Questions
What is the molecular weight of glutathione?
The molecular weight of reduced L-glutathione (GSH) is 307.32 Da. The molecular formula is C10H17N3O6S and the CAS number is 70-18-8. GSH is a tripeptide with the unusual γ-peptide bond sequence γ-L-Glu-L-Cys-Gly.
How should glutathione solutions be prepared to prevent oxidation?
GSH is susceptible to oxidation in aqueous solution, particularly at neutral or alkaline pH and in the presence of oxygen. For research applications, AbsoluteBioLab recommends dissolving GSH in slightly acidic buffer (e.g., 0.1% TFA, 10 mM HCl, or phosphate buffer pH 5.0) under an inert atmosphere (nitrogen or argon). Solutions should be prepared fresh immediately before use, or aliquoted and stored at −80°C under inert atmosphere. The GSH/GSSG ratio of prepared solutions can be confirmed by Ellman’s reagent (DTNB) assay.
What is the difference between the 1500mg and the 1500mg Refill formats?
The Glutathione 1500mg and Glutathione 1500mg Refill contain the same active compound at the same purity specification. The Refill format is designed for researchers who use the AbsoluteBioLab peptide pen system and require a convenient refill supply. Both formats are supplied with batch-specific CoA documentation.
Is a Certificate of Analysis available?
Yes. Batch-specific CoA documents — including HPLC chromatograms, MS data, and Ellman’s assay results — are available through the AbsoluteBioLab CoA Portal and are included with each order.
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