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Showing 201 - 220 of 55725 compounds

Compound ID

Compound

Pathways

PW_C000263

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17a-Hydroxypregnenolone

17a-Hydroxypregnenolone is a 21-carbon steroid that is converted from pregnenolone by cytochrome P450 17alpha hydroxylase/C17,20 lyase (CYP17, EC 1.14.99.9). 17a-Hydroxypregnenolone is an intermediate in the delta-5 pathway of biosynthesis of gonadal steroid hormones and the adrenal corticosteroids. The first, rate-limiting and hormonally regulated step in the biosynthesis of all steroid hormones is the conversion of cholesterol to pregnenolone. The conversion of cholesterol to pregnenolone is accomplished by the cleavage of the cholesterol side chain, catalyzed by a mitochondrial cytochrome P450 enzyme termed P450scc where scc designates Side Chain Cleavage. All steroid hormones are made from the pregnenolone produced by P450scc; thus, the presence or absence of each of the activities of CYP17 directs this pregnenolone towards its final metabolic pathway. While all cytochrome P450 enzymes can catalyze multiple reactions on a single active site, CYP17 is the only one described to date in which these multiple activities are differentially regulated by a physiologic process. 17a-Hydroxypregnenolone is converted to dehydroepiandrosterone by the 17,20 lyase activity of CYP17. The ratio of the 17,20 lyase to 17 alpha-hydroxylase activity of CYP17 determines the ratio of C21 to C19 steroids produced. This ratio is regulated post-translationally by at least three factors: the abundance of the electron-donating protein P450 oxidoreductase, the presence of cytochrome b5, and the serine phosphorylation of CYP17. (PMID: 12573809).

PW_C000273

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17-Hydroxyprogesterone

It serves as an intermediate in the biosynthesis of hydrocortisone and gonadal steroid hormones. It is derived from progesterone via 17-hydroxylase, a P450c17 enzyme, or from 17-hydroxypregnenolone via 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase. 17-Hydroxyprogesterone is a natural progestin and in pregnancy increases in the third trimester primarily due to fetal adrenal production. This hormone is primarily produced in the adrenal glands and to some degree in the gonads, specifically the corpus luteum of the ovary. Normal levels are 3-90 ng/dl in children, and in women, 15-70 ng/dl prior to ovulation, and 35-290 ng/dl during the luteal phase. Measurements of levels of 17-hydroxyprogesterone are useful in the evaluation of patients with suspected congenital adrenal hyperplasia as the typical enzymes that are defective, namely 21-hydroxylase and 11β-hydroxylase, lead to a build-up of 17OHP. In contrast, the rare patient with 17α-hydroxylase deficiency will have very low or undetectable levels of 17OHP. 17OHP levels can also be used to measure contribution of progestational activity of the corpus luteum during pregnancy as progesterone but not 17OHP is also contributed by the placenta.

PW_C000353

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Calcium

Calcium is essential for the normal growth and maintenance of bones and teeth, and calcium requirements must be met throughout life. Requirements are greatest during periods of growth, such as childhood, during pregnancy and when breast-feeding. Long-term calcium deficiency can lead to osteoporosis, in which the bone deteriorates and there is an increased risk of fractures. Adults need between 1,000 and 1,300 mg of calcium in their daily diet. Calcium is essential for living organisms, particularly in cell physiology, and is the most common metal in many animals. Physiologically, it exists as an ion in the body. Calcium combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Calcium is an important component of a healthy diet. A deficit can affect bone and tooth formation, while overretention can cause kidney stones. Vitamin D is needed to absorb calcium. Dairy products, such as milk and cheese, are a well-known source of calcium. However, some individuals are allergic to dairy products and even more people, particularly those of non-European descent, are lactose-intolerant, leaving them unable to consume dairy products. Fortunately, many other good sources of calcium exist. These include: seaweeds such as kelp, wakame and hijiki; nuts and seeds (like almonds and sesame); beans; amaranth; collard greens; okra; rutabaga; broccoli; kale; and fortified products such as orange juice and soy milk. Calcium has also been found to assist in the production of lymphatic fluids.

PW_C000358

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5-Hydroxy-L-tryptophan

5-Hydroxy-L-tryptophan is an aromatic amino acid naturally produced by the body from the essential amino acid L-tryptophan. 5-Hydroxy-L-tryptophan is the immediate precursor of the neurotransmitter serotonin. The conversion to serotonin is catalyzed by the enzyme aromatic L-amino acid decarboxylase (EC 4.1.1.28) (AADC1 also known as DOPA decarboxylase), an essential enzyme in the metabolism of the monoamine neurotransmitters. An accumulation of 5-hydroxy-L-tryptophan in cerebrospinal fluid occurs in aromatic L-amino acid decarboxylase deficiency (AADC deficiency) (OMIM: 608643) accompanied by an increased excretion in the urine of the patients, which are indicative of the disorder but not specific. 5-Hydroxy-L-tryptophan is also increased in other disorders such as in Parkinson's patients with severe postural instability and gait disorders. The amount of endogenous 5-hydroxy-L-tryptophan available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase (EC 1.14.16.4), indoleamine 2,3-dioxygenase (EC 1.13.11.52), and tryptophan 2,3-dioxygenase (TDO) (EC 1.13.11.11). 5-Hydroxy-L-tryptophan has been used clinically for over 30 years. In addition to its use in the treatment of depression, the therapeutic administration of 5-hydroxy-L-tryptophan has been shown to be effective in treating a wide variety of conditions, including fibromyalgia, insomnia, binge eating associated with obesity, cerebellar ataxia, and chronic headaches. 5-Hydroxy-L-tryptophan easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. Supplementation with 5-hydroxy-L-tryptophan is hypothesized to normalize serotonin synthesis, which is putatively related to its antidepressant properties (PMID: 9295177, 17240182, 16023217). When present in sufficiently high levels, 5-hydroxytryptophan can be a neurotoxin and a metabotoxin. A neurotoxin is a compound that disrupts or attacks neural cells or tissue. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Signs and symptoms of AADC deficiency generally appear in the first year of life. Affected infants may have severe developmental delay, weak muscle tone (hypotonia), muscle stiffness, difficulty moving, and involuntary writhing movements of the limbs (athetosis). They may be lacking in energy (lethargic), feed poorly, startle easily, and have sleep disturbances. Since 5-hydroxytryptophan is a precursor to serotonin, altered levels of serotonin can accumulate in the brain, which leads to abnormal neural signalling. Infants with AADC deficiency have very low levels of neural signalling molecules while individuals who consume high levels of 5-hydroxytryptophan will have very high levels of neural signalling molecules. Both conditions can lead to vomiting, nausea, extreme drowsiness, and lethargy. 5-Hydroxytryptophan (5-HTP), also known as oxitriptan (INN) is sold over-the-counter in the United Kingdom, the United States, and Canada as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under trade names such as Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. Several double-blind placebo-controlled clinical trials have demonstrated the effectiveness of 5-HTP in the treatment of depression, though a lack of high-quality studies has been noted. More and larger studies are needed to determine if 5-HTP is truly effective in treating depression.

PW_C000364

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3-Methylhistidine

3-Methylhistidine is a product of peptide bond synthesis and methylation of actin and myosin. The measurement of 3-methylhistidine provides an index of the rate of muscle protein breakdown. 3-Methylhistidine is a biomarker for meat consumption, especially chicken. It is also a biomarker for the consumption of soy products.

PW_C000366

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Caprylic acid

Caprylic acid is the common name for the eight-carbon straight-chain fatty acid known by the systematic name octanoic acid. It is found naturally in coconuts and breast milk. It is an oily liquid with a slightly unpleasant rancid taste that is minimally soluble in water. Caprylic acid is used commercially in the production of esters used in perfumery and also in the manufacture of dyes (Wikipedia).

PW_C000372

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Etiocholanolone

Etiocholanolone is the 5-beta-reduced isomer of androsterone. Etiocholanolone is a major metabolite of testosterone and androstenedione in many mammalian species including humans. It is excreted in the urine and is androgenically inactive. Classified a ketosteroid, it causes fever (it is a pyrogen), immunostimulation and leukocytosis. The pyrogenic effect of Etiocholanolone has been shown to be due to the release of interleukin-1 (IL-1) from the leukocytes that are mobilized in response to its production or injection. Etiocholanolone has anticonvulsant activity and may be an endogenous modulator of seizure susceptibility. Significantly increased values of etiocholanolone (along with testoterone and androsterone) an be detected in the urine of men with androgenic alopecia (male pattern baldness).

PW_C000373

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3-Methyl-2-oxovaleric acid

3-Methyl-2-oxovaleric acid is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. 3-Methyl-2-oxovaleric acid is a neurotoxin, an acidogen, and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues. 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 3-methyl-2-oxovaleric acid are associated with maple syrup urine disease. MSUD is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKDC), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and urine. The symptoms of MSUD often show in infancy and lead to severe brain damage if untreated. MSUD may also present later depending on the severity of the disease. If left untreated in older individuals, during times of metabolic crisis, symptoms of the condition include uncharacteristically inappropriate, extreme, or erratic behaviour and moods, hallucinations, anorexia, weight loss, anemia, diarrhea, vomiting, dehydration, lethargy, oscillating hypertonia and hypotonia, ataxia, seizures, hypoglycemia, ketoacidosis, opisthotonus, pancreatitis, rapid neurological decline, and coma. In maple syrup urine disease, the brain concentration of branched-chain ketoacids can increase 10- to 20-fold. This leads to a depletion of glutamate and a consequent reduction in the concentration of brain glutamine, aspartate, alanine, and other amino acids. The result is a compromise of energy metabolism because of a failure of the malate-aspartate shuttle and a diminished rate of protein synthesis (PMID: 15930465). 3-Methyl-2-oxovaleric acid is a keto-acid, which is a subclass of organic acids. 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 untreated MSUD. Many affected children with organic acidemias experience intellectual disability or delayed development.

PW_C000374

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Chloride ion

Under standard conditions, chlorine exists as a diatomic molecule. Chlorine is a highly toxic, pale yellow-green gas that has a specific strong smell. In nature, chlorine is most abundant as a chloride ion. Physiologically, this it. exists as an ion in the body. The chloride ion is an essential anion that the body needs for many critical functions. It also helps keep the body's acid-base balance. The amount of chloride in the blood is carefully controlled by the kidneys. Chloride ions have important physiological roles. For instance, in the central nervous system, the inhibitory action of glycine and some of the action of GABA relies on the entry of Cl- into specific neurons. Also, the chloride-bicarbonate exchanger biological transport protein relies on the chloride ion to increase the blood's capacity of carbon dioxide, in the form of the bicarbonate ion. Chloride-transporting proteins (CLC) play fundamental roles in many tissues in the plasma membrane as well as in intracellular membranes. CLC proteins form a gene family that comprises nine members in mammals, at least four of which are involved in human genetic diseases. GABA(A) receptors are pentameric complexes that function as ligand-gated chloride ion channels. WNK kinases are a family of serine-threonine kinases that have been shown to play an essential role in the regulation of electrolyte homeostasis, and they are found in diverse epithelia throughout the body that are involved in chloride ion flux. Cystic fibrosis (CF) is caused by alterations in the CF transmembrane conductance regulator (CFTCR) gene that result in deranged sodium and chloride ion transport channels. (PMID: 17539703, 17729441, 17562499, 15300163) (For a complete review see Evans, Richard B. Chlorine: state of the art. Lung (2005), 183(3), 151-167. PMID: 16078037).

PW_C000382

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4-Hydroxybenzoic acid

4-Hydroxybenzoic acid, also known as p-hydroxybenzoate or 4-carboxyphenol, 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. 4-Hydroxybenzoic acid exists as a solid, soluble (in water), and a weakly acidic compound (based on its pKa). 4-Hydroxybenzoic acid has been detected in most biofluids, including urine, blood, feces, and saliva. Within the cell, 4-hydroxybenzoic acid is primarily located in the cytoplasm and mitochondria. 4-Hydroxybenzoic acid exists in all living organisms, ranging from bacteria to humans. 4-Hydroxybenzoic acid participates in a number of enzymatic reactions. In particular, Pyruvic acid and 4-hydroxybenzoic acid can be biosynthesized from chorismate through the action of the enzyme chorismate lyase. Furthermore, 4-Hydroxybenzoic acid and octaprenyl diphosphate can be converted into 3-octaprenyl-4-hydroxybenzoate; which is catalyzed by the enzyme 4-hydroxybenzoate octaprenyltransferase. Furthermore, Pyruvic acid and 4-hydroxybenzoic acid can be biosynthesized from chorismate; which is mediated by the enzyme chorismate lyase. Finally, 4-Hydroxybenzoic acid and octaprenyl diphosphate can be converted into 3-octaprenyl-4-hydroxybenzoate through its interaction with the enzyme 4-hydroxybenzoate octaprenyltransferase. In humans, 4-hydroxybenzoic acid is involved in ubiquinone biosynthesis pathway. 4-Hydroxybenzoic acid, or p-hydroxybenzoic acid, is a phenolic derivative of benzoic acid. It a white crystalline solid that is slightly soluble in water and chloroform, but well soluble in alcohols, ether, and acetone.

PW_C000390

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Aminoadipic acid

Aminoadipic acid (2-aminoadipate) is a metabolite in the principal biochemical pathway of lysine. It is an intermediate in the metabolism (i.e. breakdown or degradation) of lysine and saccharopine. It antagonizes neuroexcitatory activity modulated by the glutamate receptor N-methyl-D-aspartate (NMDA). Aminoadipic acid has also been shown to inhibit the production of kynurenic acid, a broad spectrum excitatory amino acid receptor antagonist, in brain tissue slices (PMID: 8566117). Recent studies have shown that aminoadipic acid is elevated in prostate biopsy tissues from prostate cancer patients (PMID: 23737455). Mutations in DHTKD1 (dehydrogenase E1 and transketolase domain-containing protein 1) have been shown to cause human 2-aminoadipic aciduria and 2-oxoadipic aciduria via impaired decarboxylation of 2-oxoadipate to glutaryl-CoA, which is the last step in the lysine degradation pathway (PMID: 23141293). Aging, diabetes, sepsis, and renal failure are known to catalyze the oxidation of lysyl residues to form 2-aminoadipic acid in human skin collagen and potentially other tissues (PMID: 18448817). Proteolytic breakdown of these tissues can lead to the release of free 2-aminoadipic acid. Studies in rats indicate that aminoadipic acid (along with the three branched-chain amino acids - leucine, valine, and isoleucine) levels are elevated in the pre-diabetic phase and so aminoadipic acid may serve as a predictive biomarker for the development of diabetes (PMID: 15389298). Long-term hyperglycemia of endothelial cells can also lead to elevated levels of aminoadipate which is thought to be a sign of lysine breakdown through oxidative stress and reactive oxygen species (ROS) (PMID: 21961526). 2-Aminoadipate is a potential small-molecule marker of oxidative stress (PMID: 21647514). Therefore, depending on the circumstances aminoadipic acid can act as an acidogen, a diabetogen, an atherogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A diabetogen is a compound that can lead to type 2 diabetes. An atherogen is a compound that leads to atherosclerosis and cardiovascular disease. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of aminoadipic acid are associated with at least two inborn errors of metabolism including, 2-aminoadipic aciduria and 2-oxoadipic aciduria. Aminoadipic acid is an organic acid and 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 abnormalities, kidney abnormalities, liver damage, 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. As a diabetogen, serum aminoadipic levels appear to regulate glucose homeostasis and have been highly predictive of individuals who later develop diabetes (PMID: 24091325). In particular, aminoadipic acid lowers fasting plasma glucose levels and enhances insulin secretion from human islets. As an atherogen, aminoadipic acid has been found to be produced at high levels via protein lysine oxidation in atherosclerotic plaques (PMID: 28069522).

PW_C000391

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Capric acid

Capric acid is a member of the series of fatty acids found in oils and animal fats. The names of caproic, caprylic, and capric acids are all derived from the word caper (Latin for goat). These fatty acids are light yellowish transparent oily liquids with uncomfortable smells. They are used in organic synthesis, perfume manufacturing, medicine, lubricating grease, rubber, and dye (Chemicalland21).

PW_C000395

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β-D-Glucose

Beta-D-Glucose is a primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes. This group contains a benzene and also an ethylene group, being derived from styrolene. Coniferin, C16H22O8, occurs in the cambium of conifer wood. Emulsin converts it into glucose and coniferyl alcohol, while oxidation gives glycovanillin, which yields with emulsin glucose and vanillin. Syringin, which occurs in the bark of Syringe vulgaris, is a methoxyconiferin. Phloridzus occurs in the root-bark of various fruit trees; it hydrolyses to glucose and phloretin, which is the phloroglucin ester of paraoxyhydratropic acid. It is related to the pentosides naringin, C21HEOi1, which hydrolyses to rhamnose and naringenin, the phioroglucin ester of para-oxycinnamic acid, and hesperidin, which hydrolyses to rhamnose and hesperetin, the phloroglucin ester of meta-oxy-para-methoxycinnamic acid or isoferulic acid, C10H10O4. Classification of the glucosides is a matter of some difficulty. One based on the chemical constitution of the non-glucose part of the molecules has been proposed that frames four groups: (I) ethylene derivatives, (2) benzene derivatives, (3) styrolene derivatives, (4) anthracene derivatives. A group may also be made to include the cyanogenetic glucosides, i.e. those containing prussic acid. Other classifications follow a botanical classification, which has several advantages; in particular, plants of allied genera contain similar compounds. In this article the chemical classification will be followed, and only the more important compounds will be discussed here.

PW_C000396

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L-Arginine

Arginine is an essential amino acid that is physiologically active in the L-form. In mammals, arginine is formally classified as a semi-essential or conditionally essential amino acid, depending on the developmental stage and health status of the individual. Infants are unable to effectively synthesize arginine, making it nutritionally essential for infants. Adults, however, are able to synthesize arginine in the urea cycle. Arginine can be considered to be a basic amino acid as the part of the side chain nearest to the backbone is long, carbon-containing, and hydrophobic, whereas the end of the side chain is a complex guanidinium group. With a pKa of 12.48, the guanidinium group is positively charged in neutral, acidic, and even most basic environments. Because of the conjugation between the double bond and the nitrogen lone pairs, the positive charge is delocalized. This group is able to form multiple H-bonds. L-Arginine is an amino acid that has numerous functions in the body. It helps dispose of ammonia, is used to make compounds such as nitric oxide, creatine, L-glutamate, and L-proline, and it can be converted into glucose and glycogen if needed. In large doses, L-arginine also stimulates the release of the hormones growth hormone and prolactin. Arginine is a known inducer of mTOR (mammalian target of rapamycin) and is responsible for inducing protein synthesis through the mTOR pathway. mTOR inhibition by rapamycin partially reduces arginine-induced protein synthesis (PMID: 20841502). Catabolic disease states such as sepsis, injury, and cancer cause an increase in arginine utilization, which can exceed normal body production, leading to arginine depletion. Arginine also activates AMP kinase (AMPK) which then stimulates skeletal muscle fatty acid oxidation and muscle glucose uptake, thereby increasing insulin secretion by pancreatic beta-cells (PMID: 21311355). Arginine is found in plant and animal proteins, such as dairy products, meat, poultry, fish, and nuts. The ratio of L-arginine to lysine is also important: soy and other plant proteins have more L-arginine than animal sources of protein.

PW_C000397

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Chenodeoxycholic acid

Chenodeoxycholic acid is a bile acid. Bile acids are steroid acids found predominantly in bile of mammals. The distinction between different bile acids is minute, depends only on presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins, and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH and, consequently, require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties (e.g., membrane disruption) and there are a plethora of mechanisms to limit their accumulation in blood and tissues. (PMID: 11316487, 16037564, 12576301, 11907135). Usually conjugated with either glycine or taurine. It acts as a detergent to solubilize fats for intestinal absorption and is reabsorbed by the small intestine. It is used as cholagogue, a choleretic laxative, and to prevent or dissolve gallstones.

PW_C000412

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Caproic acid

Caproic acid is a colourless oily liquid that smells like cheese. It is a fatty acid found naturally in various animal fats and oils. Caproic acid is a medium chain triglyceride (MCT). MCTs are widely used for parenteral nutrition in individuals requiring supplemental nutrition, and are being more widely used in foods, drugs, and cosmetics (MCTs are essentially non-toxic). It is safe for human dietary consumption up to levels of 1g/kg (PMID: 10685018). Caproic acid is found to be associated with medium chain acyl-CoA dehydrogenase deficiency, which is an inborn error of metabolism.

PW_C000413

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Adenylsuccinic acid

Adenylsuccinic acid, also known as adenylosuccinate or aspartyl adenylate, belongs to the class of organic compounds known as purine ribonucleoside monophosphates. These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. Adenylsuccinic acid is slightly soluble (in water) and a moderately acidic compound (based on its pKa). Within the cell, adenylsuccinic acid is primarily located in the cytoplasm and mitochondria. In humans, adenylsuccinic acid is involved in the aspartate metabolism pathway, the azathioprine action pathway, the mercaptopurine action pathway, and the purine metabolism pathway. Adenylsuccinic acid is also involved in several metabolic disorders, some of which include myoadenylate deaminase deficiency, the lesch-nyhan syndrome (LNS) pathway, adenylosuccinate lyase deficiency, and the hypoacetylaspartia pathway. Adenylsuccinic acid is a substrate of the enzyme adenylosuccinase [EC 4.3.2.2] in purine metabolism pathway. The accumulation of adenylsuccinic acid in body fluids occurs due to a deficiency of adenylosuccinase. (KEGG; PMID 8412002).

PW_C000414

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Adenosine triphosphate

Adenosine triphosphate (ATP) is a nucleotide consisting of a purine base (adenine) attached to the first carbon atom of ribose (a pentose sugar). Three phosphate groups are esterified at the fifth carbon atom of the ribose. ATP is incorporated into nucleic acids by polymerases in the processes of DNA replication and transcription. ATP contributes to cellular energy charge and participates in overall energy balance, maintaining cellular homeostasis. ATP can act as an extracellular signaling molecule via interactions with specific purinergic receptors to mediate a wide variety of processes as diverse as neurotransmission, inflammation, apoptosis, and bone remodelling. Extracellular ATP and its metabolite adenosine have also been shown to exert a variety of effects on nearly every cell type in human skin, and ATP seems to play a direct role in triggering skin inflammatory, regenerative, and fibrotic responses to mechanical injury, an indirect role in melanocyte proliferation and apoptosis, and a complex role in Langerhans cell-directed adaptive immunity. During exercise, intracellular homeostasis depends on the matching of adenosine triphosphate (ATP) supply and ATP demand. Metabolites play a useful role in communicating the extent of ATP demand to the metabolic supply pathways. Effects as different as proliferation or differentiation, chemotaxis, release of cytokines or lysosomal constituents, and generation of reactive oxygen or nitrogen species are elicited upon stimulation of blood cells with extracellular ATP. The increased concentration of adenosine triphosphate (ATP) in erythrocytes from patients with chronic renal failure (CRF) has been observed in many studies but the mechanism leading to these abnormalities still is controversial. (PMID: 15490415, 15129319, 14707763, 14696970, 11157473).

PW_C000423

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Magnesium

Magnesium salts are essential in nutrition, being required for the activity of many enzymes, especially those concerned with oxidative phosphorylation. Physiologically, it exists as an ion in the body. It is a component of both intra- and extracellular fluids and is excreted in the urine and feces. Deficiency causes irritability of the nervous system with tetany, vasodilatation, convulsions, tremors, depression, and psychotic behavior. Magnesium ion in large amounts is an ionic laxative, and magnesium sulfate (Epsom salts) is sometimes used for this purpose. So-called "milk of magnesia" is a water suspension of one of the few insoluble magnesium compounds, magnesium hydroxide; the undissolved particles give rise to its appearance and name. Milk of magnesia is a mild base, and is commonly used as an antacid.

PW_C000424

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TG(10:0/10:0/10:0)[iso]

TG(10:0/10:0/10:0) or tricapric glyceride is a tridecanoic acid triglyceride or medium chain triglyceride. Triglycerides (TGs) are also known as triacylglycerols or triacylglycerides, meaning that they are glycerides in which the glycerol is esterified with three fatty acid groups (i.e. fatty acid tri-esters of glycerol). TGs may be divided into three general types with respect to their acyl substituents. They are simple or monoacid if they contain only one type of fatty acid, diacid if they contain two types of fatty acids and triacid if three different acyl groups. Chain lengths of the fatty acids in naturally occurring triglycerides can be of varying lengths and saturations but 16, 18 and 20 carbons are the most common. TG(10:0/10:0/10:0), in particular, consists of one chain of decanoic acid at the C-1 position, one chain of decanoic acid at the C-2 position and one chain of decanoic acid acid at the C-3 position. TGs are the main constituent of vegetable oil and animal fats. TGs are major components of very low density lipoprotein (VLDL) and chylomicrons, play an important role in metabolism as energy sources and transporters of dietary fat. They contain more than twice the energy (9 kcal/g) of carbohydrates and proteins. In the intestine, triglycerides are split into glycerol and fatty acids (this process is called lipolysis) with the help of lipases and bile secretions, which can then move into blood vessels. The triglycerides are rebuilt in the blood from their fragments and become constituents of lipoproteins, which deliver the fatty acids to and from fat cells among other functions. Various tissues can release the free fatty acids and take them up as a source of energy. Fat cells can synthesize and store triglycerides. When the body requires fatty acids as an energy source, the hormone glucagon signals the breakdown of the triglycerides by hormone-sensitive lipase to release free fatty acids. As the brain cannot utilize fatty acids as an energy source, the glycerol component of triglycerides can be converted into glucose for brain fuel when it is broken down. (www.cyberlipid.org, www.wikipedia.org). TAGs can serve as fatty acid stores in all cells, but primarily in adipocytes of adipose tissue. The major building block for the synthesis of triacylglycerides, in non-adipose tissue, is glycerol. Adipocytes lack glycerol kinase and so must use another route to TAG synthesis. Specifically, dihydroxyacetone phosphate (DHAP), which is produced during glycolysis, is the precursor for TAG synthesis in adipose tissue. DHAP can also serve as a TAG precursor in non-adipose tissues, but does so to a much lesser extent than glycerol. The use of DHAP for the TAG backbone depends on whether the synthesis of the TAGs occurs in the mitochondria and ER or the ER and the peroxisomes. The ER/mitochondria pathway requires the action of glycerol-3-phosphate dehydrogenase to convert DHAP to glycerol-3-phosphate. Glycerol-3-phosphate acyltransferase then esterifies a fatty acid to glycerol-3-phosphate thereby generating lysophosphatidic acid. The ER/peroxisome reaction pathway uses the peroxisomal enzyme DHAP acyltransferase to acylate DHAP to acyl-DHAP which is then reduced by acyl-DHAP reductase. The fatty acids that are incorporated into TAGs are activated to acyl-CoAs through the action of acyl-CoA synthetases. Two molecules of acyl-CoA are esterified to glycerol-3-phosphate to yield 1,2-diacylglycerol phosphate (also known as phosphatidic acid). The phosphate is then removed by phosphatidic acid phosphatase (PAP1), to generate 1,2-diacylglycerol. This diacylglycerol serves as the substrate for addition of the third fatty acid to make TAG. Intestinal monoacylglycerols, derived from dietary fats, can also serve as substrates for the synthesis of 1,2-diacylglycerols.
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