thiol group comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-07-03. Numbers and descriptions here follow the published literature rather than marketing material.
In cells, glutathione helps maintain the reducing environment of the cytosol and supports enzymes that counteract reactive oxygen species. It acts as a cofactor for glutathione peroxidases, which reduce hydrogen peroxide and lipid peroxides, and for glutathione S-transferases, which conjugate electrophiles. The ratio of GSH to GSSG is often used as an indicator of oxidative stress, although the ratio can vary by compartment and cell type. Glutathione also stores cysteine, an amino acid that can be limiting for protein synthesis and antioxidant defense.
Synthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine. The first step is rate-limiting and is influenced by cysteine availability and feedback inhibition by GSH. Breakdown involves gamma-glutamyl transferase and subsequent peptidases, which release constituent amino acids for reuse. Because turnover differs among tissues, measurements from blood, plasma, and tissues are not directly interchangeable. Research continues to clarify how compartment-specific pools are regulated in health and disease.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It contains an unusual gamma-glutamyl bond between glutamate and cysteine, which resists cleavage by many peptidases. The reduced form, GSH, carries a thiol group on cysteine and is the dominant intracellular form in most cells. Its structure allows it to participate in redox reactions and to serve as a sulfur donor. The oxidized form, GSSG, consists of two GSH molecules joined by a disulfide bond.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | For reduced glutathione; the oxidized dimer has two sulfur atoms. |
| Molar mass | 307.32 g/mol | Calculated for the reduced form. |
| Appearance | White to off-white crystalline powder | Typical for solid reagent; solutions are usually colorless. |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar organic solvents. |
| Typical storage | -20 °C, desiccated, protected from light | Limits oxidation, moisture uptake, and degradation. |
=== In humans and other animals === Low levels of synephrine have been found in normal human urine, as well as in other mammalian tissue. To reduce the likelihood that the synephrine detected in urine had a dietary origin, the subjects tested by Ibrahim and co-workers abstained from the consumption of any citrus products for 48 hours prior to providing urine samples. A 2006 study of synephrine in human blood platelets by D'Andrea and co-workers showed increased levels in platelets from patients suffering from aura-associated migraine (0.72 ng/108 platelets, compared to 0.33 ng/108 platelets in control subjects). Earlier, the same research group had reported a normal human blood plasma level of synephrine of 0.90–13.69 ng/mL.
== Miscellaneous == John Parke Custis* (1777), stepson of George Washington Philip Hamilton (1800), eldest son of Alexander Hamilton and Elizabeth Schuyler Hamilton David Augustus Clarkson (1810), landowner and grandson-in-law of Robert R. Livingston James Lenox (1818), bibliophile, founder of the Lenox Library, later incorporated into the New York Public Library; also founder of the Presbyterian Hospital John Lloyd Stephens (1822), explorer, archaeologist, special ambassador to Central America, and president of the Panama Railroad William R. Travers (1838), founder of the Travers Stakes William H. Herriman (1849), expatriate American art collector Cornelius Jeremiah Vanderbilt* (1850), son of Cornelius Vanderbilt Augustus Newbold Morris (1860), socialite and former president of The Metropolitan Club Winthrop Rutherfurd (1884), socialite known for his romance with Consuelo Vanderbilt and marriage to Lucy Mercer Rutherfurd, mistress of Franklin D. Roosevelt Gavin Arthur (1922), San Francisco astrologer and sexologist; grandson of U.S. President Chester A. Arthur Oswald Jacoby (1922), bridge player Fred Glazer (1958), librarian and director of the West Virginia Library Commission Arthur MacArthur IV (1960), son of General of the Army Douglas MacArthur Ashrita Furman (1976), holder of the most Guinness Book of World Records records Daniel Kottke (1977), college friend of Steve Jobs and 12th employee of Apple Inc. Sergey Kudrin (1981), chess grandmaster and three-time winner of the U.S.
== Effects of MPPT on wound healing == MPPT has been evaluated in a preclincial wound healing model and in a 266 patient comparative clinical study, which included a wide range of wound types. The study found that MPPT reduced the time to achieving an infection-free and healing wound by 60% compared to a topical antibiotic (genamicin) and to the antiseptic iodine. MPPT also reduced the number of hospitalisation days by 31% compared to the antibiotic. At Bristol University Hospital, MPPT was evaluated for use on wounds. The study included nine dehisced surgical wounds and one category 4 pressure ulcer. Standard-of-care for these types of wounds are one week with UrgoClean followed by 2 or more weeks with Negative Pressure Wound Therapy (NPWT). Wounds receiving MPPT were able to achieve the same stage of wound healing in 4–5 days as would have required 3 or more weeks with standard-of-care, thus offering savings of 67%. All wounds receiving MPPT closed. MPPT has also been used on diabetic foot ulcers and venous leg ulcers, including ulcers that were chronic and non-healing and in all cases it has been able to promote healing. MPPT has also been used on pressure ulcers, including chronic non-healing ulcers and was in a similar manner able to promote healing. A poster was recently presented by the Birmingham University Hospitals at the British Association of Dermatologists, which showed that MPPT was able to assist the healing of 3 chronic, stable pyoderma gangrenosum ulcers. In one patient, it was possible to reduce the dose of immunosuppressant.
=== Anaplasia === Anaplasia is defined as cells being in an undifferentiated state and it is often associated with cancer. Often this loss of mature cell markers or morphology can be due to dedifferentiation, but it is sometimes used to refer to cells with incomplete differentiation presenting large variety in size and shape. While its definition can be conflated with dedifferentiation, it is more often perceived as a loss of differentiation leading to abnormal cell activity, including but not limited to tumorigenesis. However, dedifferentiation is often perceived as a reversion to a different cell type for regenerative purposes. In anaplastic cells, there is often an increase in proliferation and abnormal cellular organization, characteristics that are also present in dedifferentiated cells.
=== Cardiovascular system === Meta-analyses have reported a reduced risk of death from ischemic heart disease and from cerebrovascular disease among vegetarians. A 2023 systematic review and meta-analysis of prospective cohort studies found that vegetarian diets were associated with a reduced risk of cardiovascular disease overall and of ischemic heart disease in particular, while evidence for stroke was less clear.
Sources: en.wikipedia.org
says that none will be opened after the Cleves, Ohio, location, failed their expectations and closed in September 2024 after opening in February of the previous year. In 2025, Roy Rogers will open a third location in Leesburg, Virginia, where it has already has a strong presence as well as one in Cherry Hill, New Jersey.
=== Development === In the course of his work on lysozyme, Chain read papers on the enzyme in the British Journal of Experimental Pathology by Alexander Fleming in volumes 3 and 8, and by Florey in volume 11. While doing so he came across Fleming's paper discussing the antibacterial effects of Penicillium notatum mould in volume 10. The erroneous impression given by Fleming that penicillin was a bactericidal enzyme led Chain to consider that it would be similar to lysozyme. Money was short at the time; the office had an overdraft of £500 (equivalent to £31,000 in 2025) and Florey had to forbid the purchase of any further equipment. Chain and Florey decided to create a large research project on antibacterial substances produced by micro-organisms that could attract long-term funding. Three sources were initially chosen for investigation: Bacillus subtilis, Trueperella pyogenes and penicillin mould. Florey later said:
4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the para position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white crystalline solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and carboxyl groups. The compound occurs extensively in the natural world. In industry, PABA is prepared mainly by two routes: Reduction of 4-nitrobenzoic acid Hoffman degradation of the monoamide derived from terephthalic acid. Food sources of PABA include liver, brewer's yeast (and unfiltered beer), kidney, molasses, mushrooms, and whole grains. Other food sources of PABA include spinach and oat seeds.
As of 2016, challenges including optimizing sample treatment, optimizing disk surfaces, developing readers that can deploy multiple colors of light delivery and sensing for multiplexing, and for clinical use, obtaining regulatory approvals. The field is similar to lab-on-a-chip platforms. As of 2010 companies including Gyros AB, Tecan, and Burstein Technologies were working on bringing CD/DVD based immunoassays and equipment to market. Bioanalysis Microanalysis Immunoscreening List of chemical analysis methods
Sources: en.wikipedia.org
GSH is the reduced form with a free thiol group, while GSSG is the oxidized disulfide-linked dimer. Most assays distinguish the two because their balance reflects redox conditions. The names are not interchangeable.
It is synthesized in the body from amino acids, so it is not classified as an essential dietary nutrient for most people. Dietary and supplemental forms are studied for their effects on tissue levels and health markers. Evidence varies by population and outcome.
The phrase highlights its high intracellular concentration and its role in several antioxidant and detoxification reactions. It is not the only antioxidant, and the term can oversimplify its functions. Scientific descriptions usually specify the pathway or enzyme involved.
GSH is the reduced thiol form, while GSSG is the disulfide-linked oxidized dimer. The GSH:GSSG ratio is used as a redox indicator, though the ratio can vary with sample handling and cell type.