Reaction Process: PathBank:SMP0012034
Zeaxanthin Biosynthesis related metabolites
find 10 related metabolites which is associated with chemical reaction(pathway) Zeaxanthin Biosynthesis
-Carotene ⟶ B-Carotene
beta-Carotene
Beta-carotene is a cyclic carotene obtained by dimerisation of all-trans-retinol. A strongly-coloured red-orange pigment abundant in plants and fruit and the most active and important provitamin A carotenoid. It has a role as a biological pigment, a provitamin A, a plant metabolite, a human metabolite, a mouse metabolite, a cofactor, a ferroptosis inhibitor and an antioxidant. It is a cyclic carotene and a carotenoid beta-end derivative. Beta-carotene, with the molecular formula C40H56, belongs to the group of carotenoids consisting of isoprene units. The presence of long chains of conjugated double bonds donates beta-carotene with specific colors. It is the most abundant form of carotenoid and it is a precursor of the vitamin A. Beta-carotene is composed of two retinyl groups. It is an antioxidant that can be found in yellow, orange and green leafy vegetables and fruits. Under the FDA, beta-carotene is considered as a generally recognized as safe substance (GRAS). Beta-Carotene is a natural product found in Epicoccum nigrum, Lonicera japonica, and other organisms with data available. Beta-Carotene is a naturally-occurring retinol (vitamin A) precursor obtained from certain fruits and vegetables with potential antineoplastic and chemopreventive activities. As an anti-oxidant, beta carotene inhibits free-radical damage to DNA. This agent also induces cell differentiation and apoptosis of some tumor cell types, particularly in early stages of tumorigenesis, and enhances immune system activity by stimulating the release of natural killer cells, lymphocytes, and monocytes. (NCI04) beta-Carotene is a metabolite found in or produced by Saccharomyces cerevisiae. A carotenoid that is a precursor of VITAMIN A. Beta carotene is administered to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (PORPHYRIA, ERYTHROPOIETIC). See also: Lycopene (part of); Broccoli (part of); Lycium barbarum fruit (part of). Beta-Carotene belongs to the class of organic compounds known as carotenes. These are a type of polyunsaturated hydrocarbon molecules containing eight consecutive isoprene units. Carotenes are characterized by the presence of two end-groups (mostly cyclohexene rings, but also cyclopentene rings or acyclic groups) linked by a long branched alkyl chain. Beta-carotene is therefore considered to be an isoprenoid lipid molecule. Beta-carotene is a strongly coloured red-orange pigment abundant in fungi, plants, and fruits. It is synthesized biochemically from eight isoprene units and therefore has 40 carbons. Among the carotenes, beta-carotene is distinguished by having beta-rings at both ends of the molecule. Beta-Carotene is biosynthesized from geranylgeranyl pyrophosphate. It is the most common form of carotene in plants. In nature, Beta-carotene is a precursor (inactive form) to vitamin A. Vitamin A is produed via the action of beta-carotene 15,15-monooxygenase on carotenes. In mammals, carotenoid absorption is restricted to the duodenum of the small intestine and dependent on a class B scavenger receptor (SR-B1) membrane protein, which is also responsible for the absorption of vitamin E. One molecule of beta-carotene can be cleaved by the intestinal enzyme Beta-Beta-carotene 15,15-monooxygenase into two molecules of vitamin A. Beta-Carotene contributes to the orange color of many different fruits and vegetables. Vietnamese gac and crude palm oil are particularly rich sources, as are yellow and orange fruits, such as cantaloupe, mangoes, pumpkin, and papayas, and orange root vegetables such as carrots and sweet potatoes. Excess beta-carotene is predominantly stored in the fat tissues of the body. The most common side effect of excessive beta-carotene consumption is carotenodermia, a physically harmless condition that presents as a conspicuous orange skin tint arising from deposition of the carotenoid in the outermost layer of the epidermis. Yellow food colour, dietary supplement, nutrient, Vitamin A precursor. Nutriceutical with antioxidation props. beta-Carotene is found in many foods, some of which are summer savory, gram bean, sunburst squash (pattypan squash), and other bread product. A cyclic carotene obtained by dimerisation of all-trans-retinol. A strongly-coloured red-orange pigment abundant in plants and fruit and the most active and important provitamin A carotenoid. D - Dermatologicals > D02 - Emollients and protectives > D02B - Protectives against uv-radiation > D02BB - Protectives against uv-radiation for systemic use A - Alimentary tract and metabolism > A11 - Vitamins > A11C - Vitamin a and d, incl. combinations of the two > A11CA - Vitamin a, plain D020011 - Protective Agents > D000975 - Antioxidants > D002338 - Carotenoids D018977 - Micronutrients > D014815 - Vitamins > D000072664 - Provitamins
Lycopene
Lycopene is an acyclic carotene commonly obtained from tomatoes and other red fruits. It has a role as an antioxidant and a plant metabolite. It contains a carotenoid psi-end derivative. Lycopene is a naturally occuring red carotenoid pigment that is responsible in red to pink colors seen in tomatoes, pink grapefruit, and other foods. Having a chemical formula of C40H56, lycopene is a tetraterpene assembled from eight isoprene units that are solely composed of carbon and hydrogen. Lycophene may undergo extensive isomerization that allows 1056 theoretical cis-trans configurations; however the all-trans configuration of lycopene is the most predominant isomer found in foods that gives the red hue. Lycopene is a non-essential human nutrient that is classified as a non-provitamin A carotenoid pigment since it lacks a terminal beta ionone ring and does not mediate vitamin A activity. However lycophene is a potent antioxidant molecule that scavenges reactive oxygen species (ROS) singlet oxygen. Tomato lycopene extract is used as a color additive in food products. Lycopene is a natural product found in Rhodobacter capsulatus, Afifella marina, and other organisms with data available. Lycopene is a linear, unsaturated hydrocarbon carotenoid, the major red pigment in fruits such as tomatoes, pink grapefruit, apricots, red oranges, watermelon, rosehips, and guava. As a class, carotenoids are pigment compounds found in photosynthetic organisms (plants, algae, and some types of fungus), and are chemically characterized by a large polyene chain containing 35-40 carbon atoms; some carotenoid polyene chains are terminated by two 6-carbon rings. In animals, carotenoids such as lycopene may possess antioxidant properties which may retard aging and many degenerative diseases. As an essential nutrient, lycopene is required in the animal diet. (NCI04) A carotenoid and red pigment produced by tomatoes, other red fruits and vegetables, and photosynthetic algae. It is a key intermediate in the biosynthesis of other carotenoids, and has antioxidant, anti-carcinogenic, radioprotective, and anti-inflammatory properties. Lycopene (molecular formula: C40H56) is a bright red carotenoid pigment. It is a phytochemical found in tomatoes and other red fruits. Lycopene is the most common carotenoid in the human body and is one of the most potent carotenoid antioxidants. Its name is derived from the tomatos species classification, Solanum lycopersicum. Lycopene is a terpene assembled from 8 isoprene units. Lycopene is the most powerful carotenoid quencher of singlet oxygen. Singlet oxygen from ultraviolet light is a primary cause of skin aging (Wikipedia). D020011 - Protective Agents > D000975 - Antioxidants > D002338 - Carotenoids An acyclic carotene commonly obtained from tomatoes and other red fruits. D020011 - Protective Agents > D011837 - Radiation-Protective Agents D020011 - Protective Agents > D016588 - Anticarcinogenic Agents D000893 - Anti-Inflammatory Agents D000970 - Antineoplastic Agents It is used as food colouring
Zeaxanthin
Zeaxanthin is a carotenoid xanthophyll and is one of the most common carotenoid found in nature. It is the pigment that gives corn, saffron, and many other plants their characteristic color. Zeaxanthin breaks down to form picrocrocin and safranal, which are responsible for the taste and aroma of saffron Carotenoids are among the most common pigments in nature and are natural lipid soluble antioxidants. Zeaxanthin is one of the two carotenoids (the other is lutein) that accumulate in the eye lens and macular region of the retina with concentrations in the macula greater than those found in plasma and other tissues. Lutein and zeaxanthin have identical chemical formulas and are isomers, but they are not stereoisomers. The main difference between them is in the location of a double bond in one of the end rings. This difference gives lutein three chiral centers whereas zeaxanthin has two. A relationship between macular pigment optical density, a marker of lutein and zeaxanthin concentration in the macula, and lens optical density, an antecedent of cataractous changes, has been suggested. The xanthophylls may act to protect the eye from ultraviolet phototoxicity via quenching reactive oxygen species and/or other mechanisms. Some observational studies have shown that generous intakes of lutein and zeaxanthin, particularly from certain xanthophyll-rich foods like spinach, broccoli and eggs, are associated with a significant reduction in the risk for cataract (up to 20\\%) and for age-related macular degeneration (up to 40\\%). While the pathophysiology of cataract and age-related macular degeneration is complex and contains both environmental and genetic components, research studies suggest dietary factors including antioxidant vitamins and xanthophylls may contribute to a reduction in the risk of these degenerative eye diseases. Further research is necessary to confirm these observations. (PMID: 11023002). Zeaxanthin has been found to be a microbial metabolite, it can be produced by Algibacter, Aquibacter, Escherichia, Flavobacterium, Formosa, Gramella, Hyunsoonleella, Kordia, Mesoflavibacter, Muricauda, Nubsella, Paracoccus, Siansivirga, Sphingomonas, Zeaxanthinibacter and yeast (https://reader.elsevier.com/reader/sd/pii/S0924224417302571?token=DE6BC6CC7DCDEA6150497AA3E375097A00F8E0C12AE03A8E420D85D1AC8855E62103143B5AE0B57E9C5828671F226801). It is a marker for the activity of Bacillus subtilis and/or Pseudomonas aeruginosa in the intestine. Higher levels are associated with higher levels of Bacillus or Pseudomonas. (PMID: 17555270; PMID: 12147474) Zeaxanthin is a carotenol. It has a role as a bacterial metabolite, a cofactor and an antioxidant. It derives from a hydride of a beta-carotene. Zeaxanthin is a most common carotenoid alcohols found in nature that is involved in the xanthophyll cycle. As a coexistent isomer of lutein, zeaxanthin is synthesized in plants and some micro-organisms. It gives the distinct yellow color to many vegetables and other plants including paprika, corn, saffron and wolfberries. Zeaxanthin is one of the two primary xanthophyll carotenoids contained within the retina of the eye and plays a predominant component in the central macula. It is available as a dietary supplement for eye health benefits and potential prevention of age-related macular degeneration. Zeaxanthin is also added as a food dye. Zeaxanthin is a natural product found in Bangia fuscopurpurea, Erythrobacter longus, and other organisms with data available. Carotenoids found in fruits and vegetables. Zeaxanthin accumulates in the MACULA LUTEA. See also: Saffron (part of); Corn (part of); Lycium barbarum fruit (part of). D020011 - Protective Agents > D000975 - Antioxidants > D002338 - Carotenoids
Nadide
[C21H28N7O14P2]+ (664.1169428000001)
[Spectral] NAD+ (exact mass = 663.10912) and 3,4-Dihydroxy-L-phenylalanine (exact mass = 197.06881) and Cytidine (exact mass = 243.08552) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] NAD+ (exact mass = 663.10912) and NADP+ (exact mass = 743.07545) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
1,4-Dihydronicotinamide adenine dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen) respectively. NADH is the reduced form of NAD+, and NAD+ is the oxidized form of NADH. NAD (or nicotinamide adenine dinucleotide) is used extensively in glycolysis and the citric acid cycle of cellular respiration. The reducing potential stored in NADH can be either converted into ATP through the electron transport chain or used for anabolic metabolism. ATP "energy" is necessary for an organism to live. Green plants obtain ATP through photosynthesis, while other organisms obtain it via cellular respiration. NAD is a coenzyme composed of ribosylnicotinamide 5-diphosphate coupled to adenosine 5-phosphate by a pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage. NADH is the reduced form of NAD+, and NAD+ is the oxidized form of NADH, A coenzyme composed of ribosylnicotinamide 5-diphosphate coupled to adenosine 5-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). It forms NADP with the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage.(Dorland, 27th ed) [HMDB]. NADH is found in many foods, some of which are dill, ohelo berry, fox grape, and black-eyed pea. Acquisition and generation of the data is financially supported in part by CREST/JST. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
gamma-Carotene
gamma-Carotene is a cyclic carotene obtained by the cyclization of lycopene. It is found in human serum and breast milk (PMID: 9164160). Carotenoids are isoprenoid molecules that are widespread in nature and are typically seen as pigments in fruits, flowers, birds, and crustacea. Animals are unable to synthesize carotenoids de novo and rely upon the diet as a source of these compounds. Over recent years there has been considerable interest in dietary carotenoids with respect to their potential in alleviating age-related diseases in humans. This attention has been mirrored by significant advances in cloning most of the carotenoid genes and in the genetic manipulation of crop plants with the intention of increasing levels in the diet. Studies have shown an inverse relationship between the consumption of certain fruits and vegetables and the risk of epithelial cancer. Since carotenoids are among the micronutrients found in cancer-preventive foods, detailed qualitative and quantitative determination of these compounds, particularly in fruits and vegetables and in human plasma, have recently become increasingly important (PMID: 1416048, 15003396). Gamma-carotene, also known as γ-carotene, is a member of the class of compounds known as carotenes. Carotenes are a type of unsaturated hydrocarbons containing eight consecutive isoprene units. They are characterized by the presence of two end-groups (mostly cyclohexene rings, but also cyclopentene rings or acyclic groups) linked by a long branched alkyl chain. Carotenes belonging form a subgroup of the carotenoids family. Gamma-carotene can be found in a number of food items such as corn, yellow bell pepper, fig, and papaya, which makes gamma-carotene a potential biomarker for the consumption of these food products.
Water
Water is a chemical substance that is essential to all known forms of life. It appears colorless to the naked eye in small quantities, though it is actually slightly blue in color. It covers 71\\% of Earths surface. Current estimates suggest that there are 1.4 billion cubic kilometers (330 million m3) of it available on Earth, and it exists in many forms. It appears mostly in the oceans (saltwater) and polar ice caps, but it is also present as clouds, rain water, rivers, freshwater aquifers, lakes, and sea ice. Water in these bodies perpetually moves through a cycle of evaporation, precipitation, and runoff to the sea. Clean water is essential to human life. In many parts of the world, it is in short supply. From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions) in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes. Water is also central to photosynthesis and respiration. Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process (cellular respiration). Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H+, that is, a proton) donor, can be neutralized by a base, a proton acceptor such as hydroxide ion (OH-) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7. Stomach acid (HCl) is useful to digestion. However, its corrosive effect on the esophagus during reflux can temporarily be neutralized by ingestion of a base such as aluminum hydroxide to produce the neutral molecules water and the salt aluminum chloride. Human biochemistry that involves enzymes usually performs optimally around a biologically neutral pH of 7.4. (Wikipedia). Water, also known as purified water or dihydrogen oxide, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Water can be found in a number of food items such as caraway, oxheart cabbage, alaska wild rhubarb, and japanese walnut, which makes water a potential biomarker for the consumption of these food products. Water can be found primarily in most biofluids, including ascites Fluid, blood, cerebrospinal fluid (CSF), and lymph, as well as throughout all human tissues. Water exists in all living species, ranging from bacteria to humans. In humans, water is involved in several metabolic pathways, some of which include cardiolipin biosynthesis CL(20:4(5Z,8Z,11Z,14Z)/18:0/20:4(5Z,8Z,11Z,14Z)/18:2(9Z,12Z)), cardiolipin biosynthesis cl(i-13:0/i-15:0/i-20:0/i-24:0), cardiolipin biosynthesis CL(18:0/18:0/20:4(5Z,8Z,11Z,14Z)/22:5(7Z,10Z,13Z,16Z,19Z)), and cardiolipin biosynthesis cl(a-13:0/i-18:0/i-13:0/i-19:0). Water is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis tg(i-21:0/i-13:0/21:0), de novo triacylglycerol biosynthesis tg(22:0/20:0/i-20:0), de novo triacylglycerol biosynthesis tg(a-21:0/i-20:0/i-14:0), and de novo triacylglycerol biosynthesis tg(i-21:0/a-17:0/i-12:0). Water is a drug which is used for diluting or dissolving drugs for intravenous, intramuscular or subcutaneous injection, according to instructions of the manufacturer of the drug to be administered [fda label]. Water plays an important role in the world economy. Approximately 70\\% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving .
Oxygen
Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131) [HMDB]. Oxygen is found in many foods, some of which are soy bean, watermelon, sweet basil, and spinach. Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131). V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases
Hydrogen Ion
Hydrogen ion, also known as proton or h+, is a member of the class of compounds known as other non-metal hydrides. Other non-metal hydrides are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of other non-metals. Hydrogen ion can be found in a number of food items such as lowbush blueberry, groundcherry, parsley, and tarragon, which makes hydrogen ion a potential biomarker for the consumption of these food products. Hydrogen ion exists in all living organisms, ranging from bacteria to humans. In humans, hydrogen ion is involved in several metabolic pathways, some of which include cardiolipin biosynthesis cl(i-13:0/a-25:0/a-21:0/i-15:0), cardiolipin biosynthesis cl(a-13:0/a-17:0/i-13:0/a-25:0), cardiolipin biosynthesis cl(i-12:0/i-13:0/a-17:0/a-15:0), and cardiolipin biosynthesis CL(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z)/18:1(11Z)/22:5(7Z,10Z,13Z,16Z,19Z)). Hydrogen ion is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis TG(20:3(8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)/22:5(7Z,10Z,13Z,16Z,19Z)), de novo triacylglycerol biosynthesis TG(18:2(9Z,12Z)/20:0/20:4(5Z,8Z,11Z,14Z)), de novo triacylglycerol biosynthesis TG(18:4(6Z,9Z,12Z,15Z)/18:3(9Z,12Z,15Z)/18:4(6Z,9Z,12Z,15Z)), and de novo triacylglycerol biosynthesis TG(24:0/20:5(5Z,8Z,11Z,14Z,17Z)/24:0). A hydrogen ion is created when a hydrogen atom loses or gains an electron. A positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space. Due to its extremely high charge density of approximately 2×1010 times that of a sodium ion, the bare hydrogen ion cannot exist freely in solution as it readily hydrates, i.e., bonds quickly. The hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions . Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions. Under aqueous conditions found in biochemistry, hydrogen ions exist as the hydrated form hydronium, H3O+, but these are often still referred to as hydrogen ions or even protons by biochemists. [Wikipedia])