Glutathione
An endogenous tripeptide antioxidant studied in laboratory settings for oxidative stress, phase II detoxification, and cellular protection
About Glutathione
Glutathione (GSH, CAS 70-18-8) is a naturally occurring tripeptide composed of glutamate, cysteine, and glycine with an unusual γ-peptide bond between glutamate and cysteine. It is the body's most abundant intracellular thiol antioxidant and has been studied extensively for its roles in oxidative stress defense, phase II detoxification, and redox signaling.
Glutathione was first identified in 1888 by Joseph de Rey-Pailhade, a French chemist studying yeast extracts. Its structure was elucidated in 1929 by Frederick Gowland Hopkins, who shared the 1929 Nobel Prize in Physiology or Medicine for his work on vitamins. Hopkins's structural work revealed the tripeptide's unusual γ-peptide bond between the γ-carboxyl of glutamate and the amino group of cysteine—a linkage that protects the molecule from cleavage by typical peptidases.
Over the following decades, glutathione became one of the most extensively studied small molecules in biochemistry. It is now recognized as the body's primary endogenous thiol antioxidant, present in virtually every cell at concentrations between 1 and 10 millimolar. The tripeptide participates in hundreds of biochemical reactions and serves as both a substrate and cofactor for multiple enzyme families.
Glutathione exists in two forms: reduced (GSH) and oxidized (GSSG, a disulfide-linked dimer). The ratio of GSH to GSSG is one of the most important indicators of cellular redox state, with healthy cells maintaining a ratio above 100:1. Research has documented declines in this ratio with age, oxidative stress, and various disease states, making glutathione homeostasis a major focus of cellular and aging research.
Quick Facts
| CAS Number | 70-18-8 |
|---|---|
| Molecular Formula | C₁₀H₁₇N₃O₆S |
| Molar Mass | 307.32 g/mol |
| Sequence | 3 amino acids (γ-Glu-Cys-Gly) |
| Form | Lyophilized powder |
| Purity | 99%+ (HPLC verified) |
| Third-Party Testing | Freedom Diagnostics (COA included) |
| Storage | Room temp 3–4 months; refrigerate post-reconstitution |
| Price (from) | $75.00 USD |
| SKU | PF-GLUT-1500MG |
How Glutathione Works
Glutathione participates in cellular biochemistry through multiple mechanisms: direct radical scavenging via its reactive thiol group, serving as a substrate for glutathione peroxidase to neutralize hydroperoxides, conjugating xenobiotics in phase II detoxification, and maintaining protein redox states through reversible glutathionylation.
Direct Free Radical Scavenging
Glutathione's cysteine thiol group (-SH) reacts directly with reactive oxygen and nitrogen species, including hydroxyl radicals, peroxynitrite, and singlet oxygen. This produces oxidized glutathione (GSSG), which is then recycled back to GSH by glutathione reductase using NADPH as the electron donor.
Glutathione Peroxidase Cofactor
The selenium-containing enzyme glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid hydroperoxides to water and lipid alcohols. This pathway is the cell's primary defense against accumulation of oxidative damage to cell membranes and proteins.
Phase II Detoxification
Glutathione S-transferase (GST) enzymes catalyze the conjugation of GSH to electrophilic compounds, including drug metabolites, environmental toxins, and lipid peroxidation products. The resulting GSH conjugates are more water-soluble and can be excreted, making glutathione central to xenobiotic detoxification in liver cells.
Protein Glutathionylation
GSH can form reversible disulfide bonds with cysteine residues on proteins, a modification called S-glutathionylation. This reversible modification serves as a redox-sensitive switch regulating protein function and protecting protein thiols from irreversible oxidation under conditions of oxidative stress.
Frequently Asked Questions
- What is Glutathione?
- Glutathione (GSH, CAS 70-18-8) is a naturally occurring tripeptide composed of glutamate, cysteine, and glycine with an unusual γ-peptide bond between glutamate and cysteine. It is the body's most abundant intracellular thiol antioxidant and has been studied extensively for its roles in oxidative stress defense, phase II detoxification, and redox signaling.
- What is the CAS number for Glutathione?
- The CAS number for Glutathione is 70-18-8.
- What purity is Peptide Foundry's Glutathione?
- Peptide Foundry's research peptides are manufactured to 99%+ purity. Every batch is verified by an independent third-party laboratory (Freedom Diagnostics) using high-performance liquid chromatography (HPLC) for purity and identity, Limulus amebocyte lysate (LAL) assay for bacterial endotoxin, and inductively coupled plasma mass spectrometry (ICP-MS) for heavy-metal contamination. A Certificate of Analysis is published for every product and batch.
- How should Glutathione be stored?
- Lyophilized glutathione is stable when stored refrigerated (2-8°C) in its original sealed container, protected from light and moisture. Reduced glutathione (GSH) oxidizes rapidly once in aqueous solution, so after reconstitution with bacteriostatic water use within 24-48 hours for research involving the reduced form, keep tightly capped and refrigerated between uses, and minimize headspace and air exposure.
- Does Glutathione ship with a Certificate of Analysis?
- Yes. Every batch of every product ships with a Certificate of Analysis from Freedom Diagnostics, an independent third-party analytical laboratory. The COA documents HPLC purity, peptide identity, endotoxin testing, and heavy-metals screening.
- Is Glutathione sold for human use?
- No. All products sold by Peptide Foundry are strictly for in-vitro research and laboratory use only (RUO). They are not intended for human or animal consumption, therapeutic use, or diagnostic application.
Scientific References
- Meister A, Anderson ME. Glutathione. Annu Rev Biochem. 1983;52:711-760. PubMed: 6137189
- Sies H. Glutathione and its role in cellular functions. Free Radic Biol Med. 1999;27(9-10):916-921. PubMed: 10569624
- Forman HJ, Zhang H, Rinna A. Glutathione: overview of its protective roles, measurement, and biosynthesis. Mol Aspects Med. 2009;30(1-2):1-12. PubMed: 18796312
- Lu SC. Glutathione synthesis. Biochim Biophys Acta. 2013;1830(5):3143-3153. PubMed: 22995213
This product is sold strictly for in-vitro research use only (RUO). It is not intended for human or animal consumption, therapeutic use, or diagnostic application.