Glutathione (GSH) is a biologically active tripeptide compound with a variety of important physiological functions, and its basic properties can be summarized as follows:
1. Chemical structure and composition
Molecular Formula: C₁₀H₁₇O₆SN₃
Molecular weight: about 307.33
Composition: Composed of glutamic acid, cysteine and glycine condensed by peptide bonding, containing a special γ-amide bond and a reactive sulfhydryl group (-SH).
Chemical structure formula: γ-L-glutamyl-L-cysteinyl-glycine.
2. Forms and transformations
Reduced form (G-SH): is the main active form, accounting for more than 90% of the total glutathione in the body.
Oxidized (G-S-S-G): two molecules of reduced glutathione are formed by dehydrogenation linked by a disulfide bond.
Dynamic equilibrium: catalyzed by glutathione reductase, the oxidized form can be reduced to the reduced form while consuming NADPH.
3. Distribution and content
Widespread: distributed in almost all mammalian, plant and microbial cells.
Intracellular localization: mainly in the cytoplasm (about 90%), with small amounts in the mitochondria, nucleus and endoplasmic reticulum.
Concentration difference: the content varies significantly in different tissues and organs, and the content is higher in metabolically active organs such as liver and kidney.
4. Physical properties
Appearance: white crystalline powder.
Solubility: soluble in water, dilute alcohol, liquid ammonia and dimethylformamide, insoluble in ether, acetone and other organic solvents.
Stability: antioxidant in aqueous solution, can scavenge reactive oxygen radicals and protect cells from oxidative damage.
5. Biological Functional Basis
Active sulfhydryl group: the sulfhydryl group of cysteine side chain is the core of its function, involved in redox reaction, detoxification and enzyme activity regulation.
Coenzymes: As coenzymes of certain enzymes, they activate enzyme activities and participate in the regulation of cellular metabolism.