Antioxidants

Selenium is a chemical element; it has symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium (from ) was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth).

thumb|class=skin-invert-image|Structure of the antioxidant glutathione

Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many

thumb|Glutathione (GSH) powder

Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of hydrogen peroxide molecules to water and oxygen each second.

Retinol is a hydrolytic metabolite of retinyl esters belonging to the group of vitamin A1 as a alcohol form. Retinol or other forms of vitamin A are fat-soluble vitamins that are found in food and used as a dietary supplement. Either of them is needed for vision, cellular development, maintenance of skin and mucous membranes, immune function and reproductive development. Dietary sources include fish, dairy products, and meat.

Acetylcysteine or '''N-acetylcysteine (NAC'; not to be confused with N''-acetylcarnosine, which is also abbreviated NAC) is a mucolytic that is used to treat paracetamol (acetaminophen) overdose and to loosen thick mucus in individuals with chronic bronchopulmonary disorders, such as pneumonia and bronchitis. It has been used to treat lactobezoar in infants. It can be taken intravenously, orally (swallowed by mouth), or inhaled as a mist by use of a nebulizer. It is also sometimes used as a dietary supplement.

marijuana used medicinally

group of chemical compounds

chemical compound

3,4,5-trihydroxybenzoic acid

Catechol ( or ), also known as pyrocatechol or 1,2-dihydroxybenzene, is an organic compound with the molecular formula . It is the ortho isomer of the three isomeric benzenediols. This colorless compound occurs naturally in trace amounts. It was first discovered by destructive distillation of the plant extract catechin. About 20,000 tonnes of catechol are now synthetically produced annually as a commodity organic chemical, mainly as a precursor to pesticides, flavors, and fragrances. Small amounts of catechol occur in fruits and vegetables.

pair of enantiomers

Mesalazine, also known as mesalamine or 5-aminosalicylic acid (5-ASA), is a medication used to treat inflammatory bowel disease, including ulcerative colitis and Crohn's disease. It is generally used for mildly to moderately severe disease. It is taken by mouth or rectally. The formulations which are taken by mouth appear to be similarly effective.

Pyrogallol is an organic compound with the formula C6H3(OH)3. It is a water-soluble, white solid although samples are typically brownish because of its sensitivity toward oxygen. It is one of three isomers of benzenetriols.

Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities. Diphenylamine dissolves well in many common organic solvents, and is moderately soluble in water. It is used mainly for its antioxidant properties. Diphenylamine is widely used as an industrial antioxidant, dye mordant and reagent and is also employed in agriculture as a fungicide and antihelmintic.

molecule resembling two gallic acid molecules assembled "head to tail" and bound by two lactone links and a C–C bond

chemical compound

antioxidant and food additive

class of enzymes

Metallothionein (MT) is a family of cysteine-rich, low molecular weight (MW ranging from 500 to 14000 Da) proteins. They are localized to the membrane of the Golgi apparatus. MTs have the capacity to bind both physiological (such as zinc, copper, selenium) and xenobiotic (such as cadmium, mercury, silver, arsenic, lead) heavy metals through the thiol group of its cysteine residues, which represent nearly 30% of its constituent amino acid residues.

thumb|right|upright=1.1|alt=General structure of an isothiocyanate.|General structure of an isothiocyanate.

chemical compound

enzyme family protecting the organism from oxidative damages

Ethoxyquin (EMQ) is a quinoline-based antioxidant used as a food preservative in certain countries and originally to control scald on pears after harvest (under commercial names such as "Stop-Scald"). It is used as a preservative in some pet foods to slow the development of rancidity of fats. Ethoxyquin is also used in some spices to prevent color loss due to oxidation of the natural carotenoid pigments.

'''N-Acetylserotonin (NAS), also known as normelatonin''', is a naturally occurring chemical intermediate in the endogenous production of melatonin from serotonin. It also has biological activity in its own right, including acting as a melatonin receptor agonist, an agonist of the TrkB, and having antioxidant effects.

Idebenone, sold under the brand name Raxone among others, is a medication that was initially developed by Takeda Pharmaceutical Company for the treatment of Alzheimer's disease and other cognitive defects. This has been met with limited success. The Swiss company Santhera Pharmaceuticals has started to investigate it for the treatment of neuromuscular diseases. In 2010, early clinical trials for the treatment of Friedreich's ataxia and Duchenne muscular dystrophy have been completed. the drug is not approved for these indications in North America or Europe. It is approved by the European Medic

mammalian protein found in Homo sapiens

Edaravone, sold under the brand name Radicava among others, is a medication used to treat stroke and amyotrophic lateral sclerosis (ALS). It is given by intravenous infusion and by mouth.

Peroxiredoxins (Prxs, ; HGNC root symbol PRDX) are a ubiquitous family of antioxidant enzymes that also control cytokine-induced peroxide levels and thereby mediate signal transduction in mammalian cells. The family members in humans are PRDX1, PRDX2, PRDX3, PRDX4, PRDX5, and PRDX6. The physiological importance of peroxiredoxins is indicated by their relative abundance (one of the most abundant proteins in erythrocytes after hemoglobin is peroxiredoxin 2). Their function is the reduction of peroxides, specifically hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite.

Pyritinol also called pyridoxine disulfide or pyrithioxine (European drug names Encephabol, Encefabol, Cerbon 6) is a semi-synthetic water-soluble analog of vitamin B6 (Pyridoxine HCl). It was produced in 1961 by Merck Laboratories by bonding 2 vitamin B6 compounds (pyridoxine) together with a disulfide bridge. Since the 1970s, it has been a prescription and OTC drug in several countries for cognitive disorders, rheumatoid arthritis, and learning disorders in children. Since the early 1990s it has been sold as a nootropic dietary supplement in the United States.

'4-tert-Butylcatechol' (TBC) is an organic chemical compound which is a derivative of catechol. TBC is available in the form of a solid crystal flake and 85% solution in methanol or water.

Probucol, sold under the trade name Lorelco among others, is an lipid-lowering agent initially developed for the treatment of coronary artery disease. Clinical use was discontinued in some countries after it was found that the drug may have the undesired effect of lowering HDL-C in patients with a previous history of heart disease. It may also cause QT interval prolongation.

Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) is a water-soluble analog of vitamin E sold by Hoffman-LaRoche. It is an antioxidant like vitamin E and it is used in biological or biochemical applications to reduce oxidative stress or damage.

'''S-Allylcysteine' (SAC) is an organosulfur compound that has the formula . It is the S-allylated derivative of the amino acid cysteine. As such only the L-enantiomer is significant biologically. SAC constituent of aged garlic. A number of related compounds are found in garlic, including the disulfide S-"allylmercaptocysteine" (SAMC, ) and γ-glutamyl-S''-allylcysteine" (GSAC).

'2,6-Di-tert-butylphenol' is an organic compound with the structural formula 2,6-((CH3)3C)2C6H3OH. This colorless solid alkylated phenol and its derivatives are used industrially as UV stabilizers and antioxidants for hydrocarbon-based products ranging from petrochemicals to plastics. Illustrative of its usefulness, it prevents gumming in aviation fuels.

chemical compound

'''N,N′-Di-2-butyl-1,4-phenylenediamine''' is an aromatic amine used industrially as an antioxidant to prevent degradation of turbine oils, transformer oils, hydraulic fluids, lubricants, waxes, and greases. It is particularly effective for hydrocarbon products produced by cracking or pyrolysis, which are characterized by high alkene content. It is also used as an polymerisation inhibitor in production of various vinyl monomers such as acrylates.

Pro-oxidants are chemicals that induce oxidative stress, either by generating reactive oxygen species or by inhibiting antioxidant systems. The oxidative stress produced by these chemicals can damage cells and tissues, for example, an overdose of the analgesic paracetamol (acetaminophen) can fatally damage the liver, partly through its production of reactive oxygen species.

'2,4-Dimethyl-6-tert-butylphenol' is the organic compound with the formula Me2(tert-Bu)C6H2OH (Me = methyl, tert-Bu = tertiary butyl). It is a colorless oil that is classified as an alkylated phenol.

thumb|right|A vehicle tire showing signs of ozone cracking

Glutaredoxins (also known as Thioltransferase) are small redox enzymes of approximately one hundred amino-acid residues that use glutathione as a cofactor. In humans this oxidation repair enzyme is also known to participate in many cellular functions, including redox signaling and regulation of glucose metabolism. Glutaredoxins are oxidized by substrates, and reduced non-enzymatically by glutathione. In contrast to thioredoxins, which are reduced by thioredoxin reductase, no oxidoreductase exists that specifically reduces glutaredoxins. Instead, glutaredoxins are reduced by the oxidation of gl

hypothetical type of antioxidant

Thujaplicin (isopropyl cycloheptatrienolone) is any of three isomeric tropolone-related natural products that have been isolated from the softwoods of the trees of Cupressaceae family. These compounds are known for their antibacterial, antifungal, and antioxidant properties. They were the first natural tropolones to be made synthetically.

6-Hydroxymelatonin (6-OHM) is a naturally occurring, endogenous, major active metabolite of melatonin. 6-Hydroxymelatonin is produced as a result of the enzymatic conversion of melatonin through hydroxylation. Similar to melatonin, 6-OHM is a full agonist of the MT1 and MT2 receptors. It is also an antioxidant and neuroprotective, and is even more potent in this regard relative to melatonin.

group of stereoisomers