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Showing 161 - 180 of 55734 compounds

Compound ID

Compound Description

Pathway Class



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Succinic acid

Succinic acid is a dicarboxylic acid. The anion, succinate, is a component of the citric acid cycle capable of donating electrons to the electron transfer chain. Succinate dehydrogenase (SDH) plays an important role in the mitochondria, being both part of the respiratory chain and the Krebs cycle. SDH with a covalently attached FAD prosthetic group, binds enzyme substrates (succinate and fumarate) and physiological regulators (oxaloacetate and ATP). Oxidizing succinate links SDH to the fast-cycling Krebs cycle portion where it participates in the breakdown of acetyl-CoA throughout the whole Krebs cycle. The succinate can readily be imported into the mitochondrial matrix by the n-butylmalonate- (or phenylsuccinate-) sensitive dicarboxylate carrier in exchange with inorganic phosphate or another organic acid, e. g. malate. (PMID 16143825) Mutations in the four genes encoding the subunits of the mitochondrial respiratory chain succinate dehydrogenase are associated with a wide spectrum of clinical presentations (i.e.: Huntington's disease. (PMID 11803021).
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Squalene is a natural raw material found in human sebum (5%) and in shark-liver oil. An unsaturated aliphatic hydrocarbon (carotenoid) with six unconjugated double bonds. (Hawley's Condensed Chemical Reference) Biological Source: Found in fish liver oils, yeast lipids and many vegetable oils, e.g. palm oil, cottonseed oil, rapeseed oil. Volatile component of scent material from Saguinus oedipus (cotton-top tamarin monkey) and Saguinus fuscicollis (saddle-back tamarin monkey). Component of adult human sebum principally responsible for the fixing of fingerprints (ChemNetBase) Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though there are botanical sources as well, including rice bran, wheat germ, and olives. All higher organisms produce squalene, including humans. It is a hydrocarbon and a triterpene. -- Wikipedia; Squalene is the biochemical precursor to the whole family of steroids. Oxidation of one of the terminal double bonds of squalene yields 2,3-squalene oxide which undergoes enzyme-catalyzed cyclization to afford lanosterol, which is then elaborated into cholesterol and other steroids. -- Wikipedia; Squalene is a low density compound often stored in the bodies of cartilaginous fishes such as sharks, which lack a swim bladder and must therefore reduce their body density with fats and oils. Squalene, which is stored mainly in the shark's liver, is lighter than water with a specific gravity of 0.855. -- Wikipedia Uses: Bactericide. Intermediate in the manufacture of pharmaceuticals, rubber chemicals and coloring materials (Physical Constants of Chemical Substances).


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Sucrose is a nonreducing disaccharide composed of glucose and fructose linked via their anomeric carbons. It is obtained commercially from sugarcane, sugar beet (beta vulgaris), and other plants and used extensively as a food and a sweetener. Sucrose is derived by crushing and extraction of sugarcane (Saccharum officinarum) with water or extraction of the sugar beet (Beta vulgaris) with water, evaporating, and purifying with lime, carbon, and various liquids. Sucrose is also obtainable from sorghum. Sucrose occurs in low percentages in honey and maple syrup. Sucrose is used as a sweetener in foods and soft drinks, in the manufacture of syrups, in invert sugar, confectionery, preserves and jams, demulcent, pharmaceutical products, and caramel. Sucrose is also a chemical intermediate for detergents, emulsifying agents, and other sucrose derivatives. Sucrose is wiidespread in seeds, leaves, fruits, flowers and roots of plants, where it functions as an energy store for metabolism and as a carbon source for biosynthesis. The annual world production of sucrose is in excess of 90 million tons mainly from the juice of sugar cane (20%) and sugar beet (17%). In addition to its use as a sweetner, sucrose is used in food products as a preservative, antioxidant, moisture control agent, stabilizer and thickening agent.


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Serotonin is a biochemical messenger and regulator, synthesized from the essential amino acid L-Tryptophan. Serotonin in the nervous system acts as a local transmitter at synapses, and as a paracrine or hormonal modulator of circuits upon diffusion, allowing a wide variety of "state-dependent" behavioral responses to different stimuli. Serotonin is widely distributed in the nervous system of vertebrates and invertebrates and some of its behavioral effects have been preserved along evolution. Such is the case of aggressive behavior and rhythmic motor patterns , including those responsible for feeding. In vertebrates, which display a wider and much more sophisticated behavioral repertoire, serotonin also modulates sleep, the arousal state , sexual behavior, and others, and deficiencies of the serotonergic system causes disorders such as depression, obsessive-compulsive disorder, phobias, posttraumatic stress disorder, epilepsy, and generalized anxiety disorder. Serotonin has three different modes of action in the nervous system: as transmitter, acting locally at synaptic boutons; upon diffusion at a distance from its release sites, producing paracrine (also called volume) effects, and by circulating in the blood stream, producing hormonal effects. The three modes can affect a single neuronal circuit. (PMID: 16047543).


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One of the pyrimidine bases of living matter. Derivation: Hydrolysis of deoxyribonucleic acid, from methylcyanoacetylurea by catalytic reduction. Use: Biochemical research. (Hawley's Condensed Chemical Dictionary). Thymine is a pyrimidine nucleobase. As the name implies, thymine may be derived by methylation of uracil at the 5th carbon. Thymine is found in the nucleic acid DNA. In RNA thymine is replaced with uracil in most cases. In DNA, thymine binds to adenine via two hydrogen bonds to assist in stabilizing the nucleic acid structures.
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Phosphoenolpyruvic acid

Phosphoenolpyruvate (PEP) is an important chemical compound in biochemistry. It has a high energy phosphate bond, and is involved in glycolysis and gluconeogenesis. In glycolysis, PEP is formed by the action of the enzyme enolase on 2-phosphoglycerate. Metabolism of PEP to pyruvate by pyruvate kinase (PK) generates 1 molecule of adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells. In gluconeogenesis, PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of 1 guanosine triphosphate molecule. This reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis. (wikipedia).
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Liothyronine is a T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3. Mildly toxic by ingestion. An experimental teratogen. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of NOx, I(-), and Cl(-). (Sax's Dangerous Properties of Industrial Materials).
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Pyroglutamic acid

Pyroglutamic acid (5-oxoproline) is a cyclized derivative of L-glutamic acid. It is an uncommon amino acid derivative in which the free amino group of glutamic acid cyclizes to form a lactam. It is formed nonenzymatically from glutamate, glutamine, and gamma-glutamylated peptides, but it can also be produced by the action of gamma-glutamylcyclotransferase on an L-amino acid. Elevated blood levels may be associated with problems of glutamine or glutathione metabolism. This compound is found in substantial amounts in brain tissue and other tissues in bound form, especially skin. It is also present in plant tissues. It is sold, over the counter, as a "smart drug" for improving blood circulation in the brain. Pyroglutamate in the urine is a biomarker for the consumption of cheese. When present in sufficiently high levels, pyroglutamic acid can act as an acidogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of pyroglutamic acid are associated with at least five inborn errors of metabolism including 5-oxoprolinuria, 5-oxoprolinase deficiency, glutathione synthetase deficiency, hawkinsinuria, and propionic acidemia. Pyroglutamic acid is an organic acid. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart, liver, and kidney abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of the untreated IEMs mentioned above. Many affected children with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures.
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Tetrahydrocorticosterone is one of the major urinary metabolites from corticosterone. Premenopausal patients with early breast cancer excrete subnormal amounts of tetrahydrocorticosterone as compared with the normal subjects of corresponding ages. (PMID 1133844).


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Sphinganine is a blocker postlysosomal cholesterol transport by inhibition of low-density lipoprotein-induced esterification of cholesterol and cause unesterified cholesterol to accumulate in perinuclear vesicles. It has been suggested the possibility that endogenous sphinganine may inhibit cholesterol transport in Niemann-Pick Type C (NPC) disease. (PMID 1817037).


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Sarcosine is the N-methyl derivative of glycine. Sarcosine is metabolized to glycine by the enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generates sarcosine from glycine. Sarcosine is a natural amino acid found in muscles and other body tissues. In the laboratory it may be synthesized from chloroacetic acid and methylamine. Sarcosine is naturally found in the metabolism of choline to glycine. Sarcosine is sweet to the taste and dissolves in water. It is used in manufacturing biodegradable surfactants and toothpastes as well as in other applications. Sarcosine is ubiquitous in biological materials and is present in such foods as egg yolks, turkey, ham, vegetables, legumes, etc. Sarcosine is formed from dietary intake of choline and from the metabolism of methionine, and is rapidly degraded to glycine. Sarcosine has no known toxicity, as evidenced by the lack of phenotypic manifestations of sarcosinemia, an inborn error of sarcosine metabolism. Sarcosinemia can result from severe folate deficiency because of the folate requirement for the conversion of sarcosine to glycine (Wikipedia). Sarcosine has recently been identified as a biomarker for invasive prostate cancer. It was found to be greatly increased during prostate cancer progression to metastasis and could be detected in urine. Sarcosine levels were also increased in invasive prostate cancer cell lines relative to benign prostate epithelial cells.(PMID: 19212411).


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The phosphoric acid ester of serine. As a constituent (residue) of proteins, its side chain can undergo O-linked glycosylation. This might be important in explaining some of the devastating consequences of diabetes. It is one of three amino acid residues that are commonly phosphorylated by kinases during cell signalling in eukaryotes. Phosphorylated serine residues are often referred to as phosphoserine. Serine proteases are a common type of protease. Serine, organic compound, one of the 20 amino acids commonly found in animal proteins. Only the L-stereoisomer appears in mammalian protein. It is not essential to the human diet, since it can be synthesized in the body from other metabolites, including glycine. Serine was first obtained from silk protein, a particularly rich source, in 1865. Its name is derived from the Latin for silk, sericum. Serine's structure was established in 1902.
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Thymidine is non-toxic and is a naturally occurring compound that exists in all living organisms and DNA viruses. 25% of DNA is composed of thymidine. RNA does not have thymidine and has uridine instead. Thymidine is a chemical compound which is a pyrimidine nucleoside. Thymidine is the DNA base T, which pairs with adenosine in double stranded DNA.
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Sphingosine 1-phosphate

Sphingosine 1-phosphate (S1P), also known as sphing-4-enine-1-phosphate, is classified as a member of the phosphosphingolipids. Phosphosphingolipids are sphingolipids with a structure based on a sphingoid base that is attached to a phosphate head group. They differ from phosphonospingolipids which have a phosphonate head group. S1P is a compound with potent bioactive actions in sphingolipid metabolism, the calcium signalling pathway, and neuroactive ligand-receptor interaction. Generated by sphingosine kinases and ceramide kinase, S1P control numerous aspects of cell physiology, including cell survival and mammalian inflammatory responses. S1P is involved in cyclooxygenase-2 induction (COX-2) and regulates the production of eicosanoids (important inflammatory mediators). S1P functions mainly via G-protein-coupled receptors and probably also has intracellular targets (PMID: 16219683 ). S1P is considered to be practically insoluble (in water) and acidic.


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Saccharopine is an intermediate in the degradation of lysine, formed by the condensation of lysine and alpha-ketoglutarate. The saccharopine pathway is the main route for lysine degradation in mammals, and its first two reactions are catalyzed by enzymatic activities known as lysine-oxoglutarate reductase (LOR) and saccharopine dehydrogenase (SDH), which reside on a single bifunctional polypeptide (LOR/SDH) (EC The reactions involved with saccharopine dehydrogenases have very strict substrate specificity for L-lysine, 2-oxoglutarate, and NADPH. LOR/SDH has been detected in a number of mammalian tissues, mainly in the liver and kidney, contributing not only to the general nitrogen balance in the organism but also to the controlled conversion of lysine into ketone bodies. A tetrameric form has also been observed in human liver and placenta. LOR activity has also been detected in brain mitochondria during embryonic development, and this opens up the question of whether or not lysine degradation has any functional significance during brain development. As a result, there is now a new focus on the nutritional requirements for lysine in gestation and infancy. Finally, LOR and/or SDH deficiencies seem to be involved in a human autosomal genetic disorder known as familial hyperlysinemia, which is characterized by serious defects in the functioning of the nervous system and characterized by a deficiency in lysine-ketoglutarate reductase, saccharopine dehydrogenase, and saccharopine oxidoreductase activities. Saccharopinuria (high amounts of saccharopine in the urine) and saccharopinemia (an excess of saccharopine in the blood) are conditions present in some inherited disorders of lysine degradation (PMID: 463877, 10567240, 10772957, 4809305). If present in sufficiently high levels, saccharopine can act as an acidogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Saccharopine is an organic acid. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). Many affected children with organic acidemias experience intellectual disability or delayed development.
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Phosphoribosyl pyrophosphate

Phosphoribosyl pyrophosphate (PRPP) is a pentosephosphate. The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides. It is formed from ribose 5-phosphate by the enzyme ribose-phosphate diphosphokinase. It plays a role in transferring phosphate groups in several reactions. (Wikipedia).
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D-Ribose, commonly referred to as simply ribose, is a five-carbon sugar found in all living cells. Ribose is not an essential nutrient because it can be synthesized by almost every tissue in the body from other substances, such as glucose. It is vital for life as a component of DNA, RNA, ATP, ADP, and AMP. In nature, small amounts of ribose can be found in ripe fruits and vegetables. Brewer's yeast, which has a high concentration of RNA, is another rich source of ribose. D-ribose is also a component of many so-called energy drinks and anti-ageing products available on the market today. Ribose is a structural component of ATP, which is the primary energy source for exercising muscle. The adenosine component is an adenine base attached to the five-carbon sugar ribose. ATP provides energy to working muscles by releasing a phosphate group, hence becoming ADP, which in turn may release a phosphate group, then becoming AMP. During intense muscular activity, the total amount of ATP available is quickly depleted. In an effort to correct this imbalance, AMP is broken down in the muscle and secreted from the cell. Once the breakdown products of AMP are released from the cell, the energy potential (TAN pool) of the muscle is reduced and ATP must then be reformed using ribose. Ribose helps restore the level of adenine nucleotides by bypassing the rate-limiting step in the de novo (oxidative pentose phosphate) pathway, which regenerates phosphoribosyl pyrophosphate (PRPP), the essential precursor for ATP. If ribose is not readily available to a cell, glucose may be converted to ribose. Ribose supplementation has been shown to increase the rate of ATP resynthesis following intense exercise. The use of ribose in men with severe coronary artery disease resulted in improved exercise tolerance. Hence, there is interest in the potential of ribose supplements to boost muscular performance in athletic activities (PMID: 17618002, Curr Sports Med Rep. 2007 Jul;6(4):254-7.).


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Uridine triphosphate

Uridine 5'-(tetrahydrogen triphosphate). A uracil nucleotide containing three phosphate groups esterified to the sugar moiety. Uridine triphosphate has the role of a source of energy or an activator of substrates in metabolic reactions, like that of adenosine triphosphate, but more specific. When Uridine triphosphate activates a substrate, UDP-substrate is usually formed and inorganic phosphate is released. (Wikipedia).


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Uridine diphosphate glucose

Uridine diphosphate glucose is a key intermediate in carbohydrate metabolism. Serves as a precursor of glycogen, can be metabolized into UDPgalactose and UDPglucuronic acid which can then be incorporated into polysaccharides as galactose and glucuronic acid. Also serves as a precursor of sucrose lipopolysaccharides, and glycosphingolipids.
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Uridine 5'-monophosphate

5'-Uridylic acid. A uracil nucleotide containing one phosphate group esterified to the sugar moiety in the 2', 3' or 5' position. Uridine 5'-monophosphate is a nucleotide that is found in RNA. It is an ester of phosphoric acid with the nucleoside uridine. UMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase uracil. (Wikipedia).
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Showing 161 - 180 of 55734 compounds