Glutathione 600 mg

What is glutathione?

Glutathione, abbreviated GSH (spelt Glutathion in German), is a tripeptide made up of glutamate, cysteine and glycine. Unlike fragments such as BPC-157 or KPV, it is not a section of a larger protein: cells synthesise it themselves from these three amino acids. As a metabolite, glutathione has been detected in humans as well as, for example, in the bacterium E. coli; it is regarded as the most abundant low-molecular-weight thiol in cells. In databases it also appears as γ-L-glutamyl-L-cysteinylglycine or simply as reduced glutathione.

Structure and key data

The following values describe the reduced form with a free thiol group (GSH):

• Sequence: γ-Glu-Cys-Gly
• Molecular formula: C10H17N3O6S
• Molar mass: 307.33 g/mol (average); monoisotopic mass 307.08 Da
• CAS number: 70-18-8
• PubChem CID: 124886
• Oxidised form for comparison: glutathione disulfide (GSSG), C20H32N6O12S2, 612.6 g/mol, PubChem CID 65359

What is unusual about the structure is the bond between glutamate and cysteine. It does not start from the α-carboxyl group, as it would in an ordinary peptide chain, but from the carboxyl group of the side chain in the γ-position. This is why the correct shorthand is γ-Glu-Cys-Gly. The cysteine carries a free thiol group through which two glutathione molecules can join to form a disulfide, GSSG.

Classification: glutathione and other tripeptides

Glutathione is the only product in the Redox Peptides category. With KPV and GHK-Cu the shop lists two further tripeptides, although they are built quite differently in chemical terms. KPV is a section of the α-MSH sequence with ordinary α-peptide bonds. GHK-Cu is the copper complex of the tripeptide GHK, in which metal binding is the defining feature. Glutathione, by contrast, is an endogenous metabolite whose chemistry is shaped by its reactive thiol group. The amount per vial differs as well: at 600 mg it is many times the 5 to 10 mg of the peptide fragments.

Research context

In cell biology, glutathione is regarded as the most important low-molecular-weight redox buffer. Its chemical role rests on two types of reaction: the reduction of oxidising agents, in which GSH is itself oxidised to GSSG, and conjugation with electrophilic compounds. Both reactions are catalysed by glutathione-dependent enzymes, among them glutathione peroxidases and glutathione S-transferases. Research addresses the redox homeostasis of cells, the biosynthesis and regulation of GSH, and methods for determining glutathione in samples.

Analytics at GPeptides

Besides purity, the oxidation state is a central analytical question for glutathione, because in solution the thiol group can react with atmospheric oxygen to form the disulfide. Mass spectrometry distinguishes the two forms clearly: singly protonated, reduced GSH gives a signal at about m/z 308.1, whereas the disulfide GSSG, at 612.6 g/mol, is roughly twice as heavy. A suitable HPLC method can separate the two forms, so that any GSSG content shows up as a peak of its own.

Glutathione is regularly tested by an independent external laboratory using HPLC and mass spectrometry. Where a certificate of analysis is available, you will find it in the lab area; without a published certificate, the overview shows the status “pending”. The route from raw material to certificate is described in the guide to quality control.