Biological Pathway: Reactome:R-HSA-71240

Kynurenic acid

C10H7NO3 (189.0425912)

Kynurenic acid is a quinolinemonocarboxylic acid that is quinoline-2-carboxylic acid substituted by a hydroxy group at C-4. It has a role as a G-protein-coupled receptor agonist, a NMDA receptor antagonist, a nicotinic antagonist, a neuroprotective agent, a human metabolite and a Saccharomyces cerevisiae metabolite. It is a monohydroxyquinoline and a quinolinemonocarboxylic acid. It is a conjugate acid of a kynurenate. Kynurenic Acid is under investigation in clinical trial NCT02340325 (FS2 Safety and Tolerability Study in Healthy Volunteers). Kynurenic acid is a natural product found in Ephedra foeminea, Ephedra intermedia, and other organisms with data available. Kynurenic acid is a uremic toxin. Uremic toxins can be subdivided into three major groups based upon their chemical and physical characteristics: 1) small, water-soluble, non-protein-bound compounds, such as urea; 2) small, lipid-soluble and/or protein-bound compounds, such as the phenols and 3) larger so-called middle-molecules, such as beta2-microglobulin. Chronic exposure of uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease. Kynurenic acid (KYNA) is a well-known endogenous antagonist of the glutamate ionotropic excitatory amino acid receptors N-methyl-D-aspartate (NMDA), alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid and kainate receptors and of the nicotine cholinergic subtype alpha 7 receptors. KYNA neuroprotective and anticonvulsive activities have been demonstrated in animal models of neurodegenerative diseases. Because of KYNAs neuromodulatory character, its involvement has been speculatively linked to the pathogenesis of a number of neurological conditions including those in the ageing process. Different patterns of abnormalities in various stages of KYNA metabolism in the CNS have been reported in Alzheimers disease, Parkinsons disease and Huntingtons disease. In HIV-1-infected patients and in patients with Lyme neuroborreliosis a marked rise of KYNA metabolism was seen. In the ageing process KYNA metabolism in the CNS of rats shows a characteristic pattern of changes throughout the life span. A marked increase of the KYNA content in the CNS occurs before the birth, followed by a dramatic decline on the day of birth. A low activity was seen during ontogenesis, and a slow and progressive enhancement occurs during maturation and ageing. This remarkable profile of KYNA metabolism alterations in the mammalian brain has been suggested to result from the development of the organisation of neuronal connections and synaptic plasticity, development of receptor recognition sites, maturation and ageing. There is significant evidence that KYNA can improve cognition and memory, but it has also been demonstrated that it interferes with working memory. Impairment of cognitive function in various neurodegenerative disorders is accompanied by profound reduction and/or elevation of KYNA metabolism. The view that enhancement of CNS KYNA levels could underlie cognitive decline is supported by the increased KYNA metabolism in Alzheimers disease, by the increased KYNA metabolism in downs syndrome and the enhancement of KYNA function during the early stage of Huntingtons disease. Kynurenic acid is the only endogenous N-methyl-D-aspartate (NMDA) receptor antagonist identified up to now, that mediates glutamatergic hypofunction. Schizophrenia is a disorder of dopaminergic neurotransmission, but modulation of the dopaminergic system by glutamatergic neurotransmission seems to play a key role. Despite the NMDA receptor antagonism, kynurenic acid also blocks, in lower doses, the nicotinergic acetycholine receptor, i.e., increased kynurenic acid levels can explain psychotic symptoms and cognitive deterioration. Kynurenic acid levels are described to be higher in the cerebrospinal fluid (CSF) and in critical central nervous system (CNS) regions of schizophrenics as compared to controls. (A3279, A3280).... Kynurenic acid (KYNA) is a well-known endogenous antagonist of the glutamate ionotropic excitatory amino acid receptors N-methyl-D-aspartate (NMDA), alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid and kainate receptors and of the nicotine cholinergic subtype alpha 7 receptors. KYNA neuroprotective and anticonvulsive activities have been demonstrated in animal models of neurodegenerative diseases. Because of KYNAs neuromodulatory character, its involvement has been speculatively linked to the pathogenesis of a number of neurological conditions including those in the ageing process. Different patterns of abnormalities in various stages of KYNA metabolism in the CNS have been reported in Alzheimers disease, Parkinsons disease and Huntingtons disease. In HIV-1-infected patients and in patients with Lyme neuroborreliosis a marked rise of KYNA metabolism was seen. In the ageing process KYNA metabolism in the CNS of rats shows a characteristic pattern of changes throughout the life span. A marked increase of the KYNA content in the CNS occurs before the birth, followed by a dramatic decline on the day of birth. A low activity was seen during ontogenesis, and a slow and progressive enhancement occurs during maturation and ageing. This remarkable profile of KYNA metabolism alterations in the mammalian brain has been suggested to result from the development of the organisation of neuronal connections and synaptic plasticity, development of receptor recognition sites, maturation and ageing. There is significant evidence that KYNA can improve cognition and memory, but it has also been demonstrated that it interferes with working memory. Impairment of cognitive function in various neurodegenerative disorders is accompanied by profound reduction and/or elevation of KYNA metabolism. The view that enhancement of CNS KYNA levels could underlie cognitive decline is supported by the increased KYNA metabolism in Alzheimers disease, by the increased KYNA metabolism in downs syndrome and the enhancement of KYNA function during the early stage of Huntingtons disease. Kynurenic acid is the only endogenous N-methyl-D-aspartate (NMDA) receptor antagonist identified up to now, that mediates glutamatergic hypofunction. Schizophrenia is a disorder of dopaminergic neurotransmission, but modulation of the dopaminergic system by glutamatergic neurotransmission seems to play a key role. Despite the NMDA receptor antagonism, kynurenic acid also blocks, in lower doses, the nicotinergic acetycholine receptor, i.e., increased kynurenic acid levels can explain psychotic symptoms and cognitive deterioration. Kynurenic acid levels are described to be higher in the cerebrospinal fluid (CSF) and in critical central nervous system (CNS) regions of schizophrenics as compared to controls. (PMID: 17062375 , 16088227). KYNA has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Kynurenic acid (KYNA) is a well-known endogenous antagonist of the glutamate ionotropic excitatory amino acid receptors N-methyl-D-aspartate (NMDA), alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid and kainate receptors and of the nicotine cholinergic subtype alpha 7 receptors. KYNA neuroprotective and anticonvulsive activities have been demonstrated in animal models of neurodegenerative diseases. Because of KYNAs neuromodulatory character, its involvement has been speculatively linked to the pathogenesis of a number of neurological conditions including those in the ageing process. Different patterns of abnormalities in various stages of KYNA metabolism in the CNS have been reported in Alzheimers disease, Parkinsons disease and Huntingtons disease. In HIV-1-infected patients and in patients with Lyme neuroborreliosis a marked rise of KYNA metabolism was seen. In the ageing process KYNA metabolism in the CNS of rats shows a characteristic pattern of changes throughout the life span. A marked increase of the KYNA content in the CNS occurs before the birth, followed by a dramatic decline on the day of birth. A low activity was seen during ontogenesis, and a slow and progressive enhancement occurs during maturation and ageing. This remarkable profile of KYNA metabolism alterations in the mammalian brain has been suggested to result from the development of the organisation of neuronal connections and synaptic plasticity, development of receptor recognition sites, maturation and ageing. There is significant evidence that KYNA can improve cognition and memory, but it has also been demonstrated that it interferes with working memory. Impairment of cognitive function in various neurodegenerative disorders is accompanied by profound reduction and/or elevation of KYNA metabolism. The view that enhancement of CNS KYNA levels could underlie cognitive decline is supported by the increased KYNA metabolism in Alzheimers disease, by the increased KYNA metabolism in downs syndrome and the enhancement of KYNA function during the early stage of Huntingtons disease. Kynurenic acid is the only endogenous N-methyl-D-aspartate (NMDA) receptor antagonist identified up to now, that mediates glutamatergic hypofunction. Schizophrenia is a disorder of dopaminergic neurotransmission, but modulation of the dopaminergic system by glutamatergic neurotransmission seems to play a key role. Despite the NMDA receptor antagonism, kynurenic acid also blocks, in lower doses, the nicotinergic acetycholine receptor, i.e., increased kynurenic acid levels can explain psychotic symptoms and cognitive deterioration. Kynurenic acid levels are described to be higher in the cerebrospinal fluid (CSF) and in critical central nervous system (CNS) regions of schizophrenics as compared to controls. (PMID: 17062375, 16088227) [HMDB] D018377 - Neurotransmitter Agents > D018683 - Excitatory Amino Acid Agents > D018691 - Excitatory Amino Acid Antagonists A quinolinemonocarboxylic acid that is quinoline-2-carboxylic acid substituted by a hydroxy group at C-4. [Raw Data] CBA11_Kynurenic-acid_pos_30eV_1-3_01_673.txt [Raw Data] CBA11_Kynurenic-acid_pos_50eV_1-3_01_675.txt [Raw Data] CBA11_Kynurenic-acid_pos_40eV_1-3_01_674.txt [Raw Data] CBA11_Kynurenic-acid_neg_30eV_1-3_01_726.txt [Raw Data] CBA11_Kynurenic-acid_pos_20eV_1-3_01_672.txt [Raw Data] CBA11_Kynurenic-acid_pos_10eV_1-3_01_671.txt [Raw Data] CBA11_Kynurenic-acid_neg_20eV_1-3_01_725.txt [Raw Data] CBA11_Kynurenic-acid_neg_50eV_1-3_01_728.txt [Raw Data] CBA11_Kynurenic-acid_neg_40eV_1-3_01_727.txt [Raw Data] CBA11_Kynurenic-acid_neg_10eV_1-3_01_724.txt Kynurenic acid, an endogenous tryptophan metabolite, is a broad-spectrum antagonist targeting NMDA, glutamate, α7 nicotinic acetylcholine receptor. Kynurenic acid is also an agonist of GPR35/CXCR8.

3-Hydroxyanthranilic acid

C7H7NO3 (153.0425912)

3-Hydroxyanthranilic acid, also known as 2-amino-3-hydroxy-benzoate or 3-ohaa, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. 3-Hydroxyanthranilic acid is a drug. 3-Hydroxyanthranilic acid exists in all living species, ranging from bacteria to humans. Within humans, 3-hydroxyanthranilic acid participates in a number of enzymatic reactions. In particular, 3-hydroxyanthranilic acid and L-alanine can be biosynthesized from L-3-hydroxykynurenine through the action of the enzyme kynureninase. In addition, 3-hydroxyanthranilic acid can be converted into cinnavalininate through the action of the enzyme catalase. 3-Hydroxyanthranilic acid is an intermediate in the metabolism of tryptophan. In humans, 3-hydroxyanthranilic acid is involved in tryptophan metabolism. Outside of the human body, 3-hydroxyanthranilic acid has been detected, but not quantified in brassicas. This could make 3-hydroxyanthranilic acid a potential biomarker for the consumption of these foods. It is new antioxidant isolated from methanol extract of tempeh. It is effective in preventing autoxidation of soybean oil and powder, while antioxidant 6,7,4-trihydroxyisoflavone is not. D000975 - Antioxidants > D016166 - Free Radical Scavengers [Raw Data] CBA14_3-OH-anthranili_pos_30eV_1-6_01_808.txt [Raw Data] CBA14_3-OH-anthranili_neg_40eV_1-6_01_832.txt [Raw Data] CBA14_3-OH-anthranili_pos_40eV_1-6_01_809.txt [Raw Data] CBA14_3-OH-anthranili_neg_20eV_1-6_01_830.txt [Raw Data] CBA14_3-OH-anthranili_neg_10eV_1-6_01_829.txt [Raw Data] CBA14_3-OH-anthranili_pos_10eV_1-6_01_806.txt [Raw Data] CBA14_3-OH-anthranili_pos_20eV_1-6_01_807.txt [Raw Data] CBA14_3-OH-anthranili_neg_30eV_1-6_01_831.txt D020011 - Protective Agents > D000975 - Antioxidants Isolated from Brassica oleracea (cauliflower) 3-Hydroxyanthranilic acid is a tryptophan metabolite in the kynurenine pathway.

L-Kynurenine

C10H12N2O3 (208.0847882)

Kynurenine is a metabolite of the amino acid tryptophan used in the production of niacin. L-Kynurenine is a central compound of the tryptophan metabolism pathway since it can change into the neuroprotective agent kynurenic acid or to the neurotoxic agent quinolinic acid. The break-up of these endogenous compounds balance can be observable in many disorders such as stroke, epilepsy, multiple sclerosis, and amyotrophic lateral sclerosis. It can also occur in neurodegenerative disorders such as Parkinsons disease, Huntingtons, and Alzheimers disease; and in mental disorders such as schizophrenia and depression. Kynurenine is a metabolite of the amino acid tryptophan used in the production of niacin. [Raw Data] CBA10_Kynurenine_pos_10eV_1-2_01_666.txt [Raw Data] CBA10_Kynurenine_pos_30eV_1-2_01_668.txt [Raw Data] CBA10_Kynurenine_pos_40eV_1-2_01_669.txt [Raw Data] CBA10_Kynurenine_pos_20eV_1-2_01_667.txt [Raw Data] CBA10_Kynurenine_pos_50eV_1-2_01_670.txt L-Kynurenine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=2922-83-0 (retrieved 2024-07-01) (CAS RN: 2922-83-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). 2-Amino-4-(2-aminophenyl)-4-oxobutanoic acid is an endogenous metabolite. L-Kynurenine is a metabolite of the amino acid L-tryptophan. L-Kynurenine is an aryl hydrocarbon receptor agonist.

Water

H2O (18.0105642)

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

O2 (31.98983)

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

Carbon dioxide

CO2 (43.98983)

Carbon dioxide is a colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals. Carbon dioxide is produced during respiration by all animals, fungi and microorganisms that depend on living and decaying plants for food, either directly or indirectly. It is, therefore, a major component of the carbon cycle. Additionally, carbon dioxide is used by plants during photosynthesis to make sugars which may either be consumed again in respiration or used as the raw material to produce polysaccharides such as starch and cellulose, proteins and the wide variety of other organic compounds required for plant growth and development. When inhaled at concentrations much higher than usual atmospheric levels, it can produce a sour taste in the mouth and a stinging sensation in the nose and throat. These effects result from the gas dissolving in the mucous membranes and saliva, forming a weak solution of carbonic acid. Carbon dioxide is used by the food industry, the oil industry, and the chemical industry. Carbon dioxide is used to produce carbonated soft drinks and soda water. Traditionally, the carbonation in beer and sparkling wine comes about through natural fermentation, but some manufacturers carbonate these drinks artificially. Leavening agent, propellant, aerating agent, preservative. Solvent for supercritical extraction e.g. of caffeine in manufacture of caffeine-free instant coffee. It is used in carbonation of beverages, in the frozen food industry and as a component of controlled atmosphere packaging (CAD) to inhibit bacterial growth. Especies effective against Gram-negative spoilage bacteria, e.g. Pseudomonas V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases

4-(2-Aminophenyl)-2,4-dioxobutanoic acid

C10H9NO4 (207.05315539999998)

4-(2-Aminophenyl)-2,4-dioxobutanoic acid is a substrate for Kynurenine/alpha-aminoadipate aminotransferase mitochondrial. [HMDB] 4-(2-Aminophenyl)-2,4-dioxobutanoic acid is a substrate for Kynurenine/alpha-aminoadipate aminotransferase mitochondrial.

2-Aminomuconic acid semialdehyde

C6H7NO3 (141.0425912)

2-aminomuconic semialdehyde is an intermediate in the oxidative metabolism of tryptophan in mammals, and takes place via the kynurenine pathway, which is also used for NAD biosynthesis in all eukaryotic organisms. 2-Aminomuconic semialdehyde is reported to be unstable and spontaneously converted to picolinic acid (regarded as metabolically inert and is excreted in the urine as a glycine conjugate), and enzymatically converted to 2-aminomuconic acid through the action of 2-aminomuconic semialdehyde dehydrogenase. (PMID: 10510494, 16267312, 14275129) [HMDB] 2-aminomuconic semialdehyde is an intermediate in the oxidative metabolism of tryptophan in mammals, and takes place via the kynurenine pathway, which is also used for NAD biosynthesis in all eukaryotic organisms. 2-Aminomuconic semialdehyde is reported to be unstable and spontaneously converted to picolinic acid (regarded as metabolically inert and is excreted in the urine as a glycine conjugate), and enzymatically converted to 2-aminomuconic acid through the action of 2-aminomuconic semialdehyde dehydrogenase. (PMID: 10510494, 16267312, 14275129).

N'-Formylkynurenine

C11H12N2O4 (236.07970319999998)

Plays an especially improtant role in photobiological responses. The excited states of N-formylkynurenine react to produce hydroxyl radicals. [HMDB] Plays an especially improtant role in photobiological responses. The excited states of N-formylkynurenine react to produce hydroxyl radicals.

L-3-Hydroxykynurenine

C10H12N2O4 (224.07970319999998)

L-3-Hydroxykynurenine (L-3-HK) is a metabolite in the kynurenine pathway, the major route of tryptophan degradation in mammals. Kynurenine 3-monooxygenase, an NADPH-dependent flavin monooxygenase, catalyses the hydroxylation of L-kynurenine to L-3-hydroxykynurenine. 3-hydroxykynurenine can be converted to 3-hydroxyanthranilate by the enzyme 3-hydroxykinureninase. It may also be converted to 4-(2-amino-3-hydroxphenyl)-2,4-dioxobutanoate by the enzyme kynurenine-oxoglutarate transaminase. L-3-Hydroxykynurenine (L-3-HK) is a known generator of highly reactive free radicals. An elevation of L-3-HK levels has been shown to constitute a significant hazard in situations of excitotoxic injury. In particular, L-3-HK may contribute to the neuronal deficits underlying HIV-associated dementia (PMID: 7830088). Pharmacological interventions aimed at decreasing L-3-HK formation may therefore be particularly useful for the treatment of neurological diseases which are associated with an abnormally enhanced flux through the kynurenine pathway (PMID: 10583474) [HMDB] L-3-Hydroxykynurenine (L-3-HK) is a metabolite in the kynurenine pathway, the major route of tryptophan degradation in mammals. Kynurenine 3-monooxygenase, an NADPH-dependent flavin monooxygenase, catalyses the hydroxylation of L-kynurenine to L-3-hydroxykynurenine. 3-hydroxykynurenine can be converted to 3-hydroxyanthranilate by the enzyme 3-hydroxykinureninase. It may also be converted to 4-(2-amino-3-hydroxphenyl)-2,4-dioxobutanoate by the enzyme kynurenine-oxoglutarate transaminase. L-3-Hydroxykynurenine (L-3-HK) is a known generator of highly reactive free radicals. An elevation of L-3-HK levels has been shown to constitute a significant hazard in situations of excitotoxic injury. In particular, L-3-HK may contribute to the neuronal deficits underlying HIV-associated dementia (PMID: 7830088). Pharmacological interventions aimed at decreasing L-3-HK formation may therefore be particularly useful for the treatment of neurological diseases which are associated with an abnormally enhanced flux through the kynurenine pathway (PMID: 10583474).

Hydrogen Ion

H+ (1.0078246)

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])

formate

CHO2- (44.997654600000004)

Formate, also known as formic acid or methanoic acid, is a member of the class of compounds known as carboxylic acids. Carboxylic acids are compounds containing a carboxylic acid group with the formula -C(=O)OH. Formate is soluble (in water) and a weakly acidic compound (based on its pKa). Formate can be found in a number of food items such as mammee apple, chicory roots, malabar spinach, and grapefruit, which makes formate a potential biomarker for the consumption of these food products. Formate (IUPAC name: methanoate) is the anion derived from formic acid. Its formula is represented in various equivalent ways: CHOO‚àí or HCOO‚àí or HCO2‚àí. It is the product of deprotonation of formic acid. It is the simplest carboxylate anion. A formate (compound) is a salt or ester of formic acid . Formate, also known as formic acid or methanoic acid, is a member of the class of compounds known as carboxylic acids. Carboxylic acids are compounds containing a carboxylic acid group with the formula -C(=O)OH. Formate is soluble (in water) and a weakly acidic compound (based on its pKa). Formate can be found in a number of food items such as mammee apple, chicory roots, malabar spinach, and grapefruit, which makes formate a potential biomarker for the consumption of these food products. Formate (IUPAC name: methanoate) is the anion derived from formic acid. Its formula is represented in various equivalent ways: CHOO− or HCOO− or HCO2−. It is the product of deprotonation of formic acid. It is the simplest carboxylate anion. A formate (compound) is a salt or ester of formic acid .

Kynurenine

C10H12N2O3 (208.0847882)

L-Kynurenine is a metabolite of the amino acid L-tryptophan. L-Kynurenine is an aryl hydrocarbon receptor agonist.

N-Formylkynurenine

C11H12N2O4 (236.07970319999998)

H2O

H2O (18.0105642)

An oxygen hydride consisting of an oxygen atom that is covalently bonded to two hydrogen atoms. Water. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=7732-18-5 (retrieved 2024-10-17) (CAS RN: 7732-18-5). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).

Kynurenic acid

C10H7NO3 (189.0425912)

MS2 deconvoluted using MS2Dec from all ion fragmentation data, MetaboLights identifier MTBLS1040; HCZHHEIFKROPDY-UHFFFAOYSA-N_STSL_0005_Kynurenic acid_2000fmol_180410_S2_LC02_MS02_66; Spectrum acquired as described in Naz et al 2017 PMID 28641411. Preparation and submission to MassBank of North America by Chaleckis R. and Tada I. MS2 deconvoluted using CorrDec from all ion fragmentation data, MetaboLights identifier MTBLS1040; Spectrum acquired as described in Naz et al 2017 PMID 28641411. Preparation and submission to MassBank of North America by Chaleckis R. and Tada I. D018377 - Neurotransmitter Agents > D018683 - Excitatory Amino Acid Agents > D018691 - Excitatory Amino Acid Antagonists relative retention time with respect to 9-anthracene Carboxylic Acid is 0.374 relative retention time with respect to 9-anthracene Carboxylic Acid is 0.376 relative retention time with respect to 9-anthracene Carboxylic Acid is 0.370 relative retention time with respect to 9-anthracene Carboxylic Acid is 0.372 Kynurenic acid, an endogenous tryptophan metabolite, is a broad-spectrum antagonist targeting NMDA, glutamate, α7 nicotinic acetylcholine receptor. Kynurenic acid is also an agonist of GPR35/CXCR8. Kynurenic acid, an endogenous tryptophan metabolite, is a broad-spectrum antagonist targeting NMDA, glutamate, α7 nicotinic acetylcholine receptor. Kynurenic acid is also an agonist of GPR35/CXCR8. Kynurenic acid, an endogenous tryptophan metabolite, is a broad-spectrum antagonist targeting NMDA, glutamate, α7 nicotinic acetylcholine receptor. Kynurenic acid is also an agonist of GPR35/CXCR8. Transtorine is a quinoline alkaloid, found from Ephedra transitoria, with antibacterial activity[1]. Transtorine is a quinoline alkaloid, found from Ephedra transitoria, with antibacterial activity[1].