Reaction Process: WikiPathways:WP3580

Methionine de novo and salvage pathway related metabolites

find 17 related metabolites which is associated with chemical reaction(pathway) Methionine de novo and salvage pathway

Choline ⟶ Betaine

View the spectrum consensus network of the metabolites related with current reaction.

Putrescine

1,4-Diaminobutane, puriss., >=99.0\\% (GC)

C4H12N2 (88.1)


Putrescine is a four-carbon alkane-alpha,omega-diamine. It is obtained by the breakdown of amino acids and is responsible for the foul odour of putrefying flesh. It has a role as a fundamental metabolite and an antioxidant. It is a conjugate base of a 1,4-butanediammonium. Putrescine is a toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine. Putrescine is a solid. This compound belongs to the polyamines. These are compounds containing more than one amine group. Known drug targets of putrescine include putrescine-binding periplasmic protein, ornithine decarboxylase, and S-adenosylmethionine decarboxylase proenzyme. Putrescine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). 1,4-Diaminobutane is a natural product found in Eupatorium cannabinum, Populus tremula, and other organisms with data available. Putrescine is a four carbon diamine produced during tissue decomposition by the decarboxylation of amino acids. Polyamines, including putrescine, may act as growth factors that promote cell division; however, putrescine is toxic at high doses. Putrescine 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.Putrescine is a polyamine. Putrescine is related to cadaverine (another polyamine). Both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses. Putrescine and cadaverine are largely responsible for the foul odor of putrefying flesh, but also contribute to the odor of such processes as bad breath and bacterial vaginosis. Putrescine is also found in semen. Putrescine attacks s-adenosyl methionine and converts it to spermidine. Spermidine in turn attacks another s-adenosyl methionine and converts it to spermine. Putrescine is synthesized in small quantities by healthy living cells by the action of ornithine decarboxylase. The polyamines, of which putrescine is one of the simplest, appear to be growth factors necessary for cell division. Putrescine apparently has specific role in skin physiology and neuroprotection. Pharmacological interventions have demonstrated convincingly that a steady supply of polyamines is a prerequisite for cell proliferation to occur. Genetic engineering of polyamine metabolism in transgenic rodents has shown that polyamines play a role in spermatogenesis, skin physiology, promotion of tumorigenesis and organ hypertrophy as well as neuronal protection. Transgenic activation of polyamine catabolism not only profoundly disturbs polyamine homeostasis in most tissues, but also creates a complex phenotype affecting skin, female fertility, fat depots, pancreatic integrity and regenerative growth. Transgenic expression of ornithine decarboxylase antizyme has suggested that this unique protein may act as a general tumor suppressor. Homozygous deficiency of the key biosynthetic enzymes of the polyamines, ornithine and S-adenosylmethionine decarboxylase is not compatible with murine embryogenesis. (A3286, A3287). Putrescine is a metabolite found in or produced by Saccharomyces cerevisiae. A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine. Putrescine is a polyamine. Putrescine is related to cadaverine (another polyamine). Both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses. Putrescine and cadaverine are largely responsible for the foul odor of putrefying flesh, but also contribute to the odor of such processes as bad breath and bacterial vaginosis. Putrescine has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID:22626821). It is also found in semen. Putrescine attacks s-adenosyl methionine and converts it to spermidine. Spermidine in turn attacks another s-adenosyl methionine and converts it to spermine. Putrescine is synthesized in small quantities by healthy living cells by the action of ornithine decarboxylase. The polyamines, of which putrescine is one of the simplest, appear to be growth factors necessary for cell division. Putrescine apparently has specific role in skin physiology and neuroprotection. (PMID:15009201, 16364196). Pharmacological interventions have demonstrated convincingly that a steady supply of polyamines is a prerequisite for cell proliferation to occur. Genetic engineering of polyamine metabolism in transgenic rodents has shown that polyamines play a role in spermatogenesis, skin physiology, promotion of tumorigenesis and organ hypertrophy as well as neuronal protection. Transgenic activation of polyamine catabolism not only profoundly disturbs polyamine homeostasis in most tissues, but also creates a complex phenotype affecting skin, female fertility, fat depots, pancreatic integrity and regenerative growth. Transgenic expression of ornithine decarboxylase antizyme has suggested that this unique protein may act as a general tumor suppressor. Homozygous deficiency of the key biosynthetic enzymes of the polyamines, ornithine and S-adenosylmethionine decarboxylase is not compatible with murine embryogenesis. Putrescine can be found in Citrobacter, Corynebacterium, Cronobacter and Enterobacter (PMID:27872963) (https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12099). Putrescine is an organic chemical compound related to cadaverine; both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses. The two compounds are largely responsible for the foul odor of putrefying flesh, but also contribute to the odor of such processes as bad breath and bacterial vaginosis. They are also found in semen and some microalgae, together with related molecules like spermine and spermidine. A four-carbon alkane-alpha,omega-diamine. It is obtained by the breakdown of amino acids and is responsible for the foul odour of putrefying flesh. Acquisition and generation of the data is financially supported in part by CREST/JST. KEIO_ID B001

   

2-Oxo-4-methylthiobutanoic acid

2-Keto-4-methylthiobutyric acid, monosodium salt

C5H8O3S (148.0194)


2-oxo-4-methylthiobutanoate, also known as 2-keto-4-methylthiobutyric acid, 2-keto-4-methylthiobutyrate or 4-(methylsulfanyl)-2-oxobutanoic acid, is a member of the class of compounds known as thia- fatty acids. Thia-fatty acids are fatty acid derivatives obtained by insertion of a sulfur atom at specific positions in the chain. Thus, 2-oxo-4-methylthiobutanoate is a fatty acid lipid molecule. 2-oxo-4-methylthiobutanoate is slightly soluble (in water) and a weakly acidic compound (based on its pKa). 2-oxo-4-methylthiobutanoate can be synthesized from L-methionine and butyric acid. 2-oxo-4-methylthiobutanoate can also be synthesized into S-adenosyl-4-methylthio-2-oxobutanoic acid. 2-oxo-4-methylthiobutanoate can be found in a number of food items such as cloves, highbush blueberries, common beets, and cashew nuts. 2-oxo-4-methylthiobutanoate can be found in urine. Within the cell, 2-oxo-4-methylthiobutanoate is primarily located in the cytoplasm and in the membrane. 2-oxo-4-methylthiobutanoate has been found in all living species, from bacteria to humans. In humans, 2-oxo-4-methylthiobutanoate is found to be involved in several metabolic disorders, some of those are S-adenosylhomocysteine (SAH) hydrolase deficiency, methylenetetrahydrofolate reductase deficiency (MTHFRD), methionine adenosyltransferase deficiency, and glycine N-methyltransferase deficiency. 4-Methylthio-2-oxobutanoic acid is the direct precursor of methional, which is a potent inducer of apoptosis in a BAF3 murine lymphoid cell line which is interleukin-3 (IL3)-dependent (PMID: 7848263). 2-oxo-4-methylthiobutanoic acid, also known as 2-keto-4-methylthiobutyrate or 4-methylthio-2-oxobutanoate, is a member of the class of compounds known as thia fatty acids. Thia fatty acids are fatty acid derivatives obtained by insertion of a sulfur atom at specific positions in the chain. Thus, 2-oxo-4-methylthiobutanoic acid is considered to be a fatty acid lipid molecule. 2-oxo-4-methylthiobutanoic acid is slightly soluble (in water) and a weakly acidic compound (based on its pKa). 2-oxo-4-methylthiobutanoic acid can be synthesized from L-methionine and butyric acid. 2-oxo-4-methylthiobutanoic acid can also be synthesized into S-adenosyl-4-methylthio-2-oxobutanoic acid. 2-oxo-4-methylthiobutanoic acid can be found in a number of food items such as leek, hickory nut, brussel sprouts, and giant butterbur, which makes 2-oxo-4-methylthiobutanoic acid a potential biomarker for the consumption of these food products. 2-oxo-4-methylthiobutanoic acid can be found primarily in urine. 2-oxo-4-methylthiobutanoic acid exists in all living species, ranging from bacteria to humans. In humans, 2-oxo-4-methylthiobutanoic acid is involved in the methionine metabolism. 2-oxo-4-methylthiobutanoic acid is also involved in several metabolic disorders, some of which include s-adenosylhomocysteine (SAH) hydrolase deficiency, homocystinuria-megaloblastic anemia due to defect in cobalamin metabolism, cblg complementation type, glycine n-methyltransferase deficiency, and cystathionine beta-synthase deficiency.

   

5-methylthioadenosine (MTA)

(2R,3R,4S,5S)-2-(6-amino-9H-purin-9-yl)-5-[(methylsulfanyl)methyl]oxolane-3,4-diol

C11H15N5O3S (297.0896)


5-Methylthioadenosine, also known as MTA or thiomethyladenosine, belongs to the class of organic compounds known as 5-deoxy-5-thionucleosides. These are 5-deoxyribonucleosides in which the ribose is thio-substituted at the 5position by a S-alkyl group. 5-Methylthioadenosine is metabolized solely by MTA-phosphorylase, to yield 5-methylthioribose-1-phosphate and adenine, a crucial step in the methionine and purine salvage pathways, respectively. 5-Methylthioadenosine exists in all living species, ranging from bacteria to humans. 5-Methylthioadenosine (MTA) is a naturally occurring sulfur-containing nucleoside present in all mammalian tissues. Within humans, 5-methylthioadenosine participates in a number of enzymatic reactions. In particular, 5-methylthioadenosine and spermidine can be biosynthesized from S-adenosylmethioninamine and putrescine through the action of the enzyme spermidine synthase. In addition, 5-methylthioadenosine can be converted into 5-methylthioribose 1-phosphate and L-methionine; which is catalyzed by the enzyme S-methyl-5-thioadenosine phosphorylase. It is produced from S-adenosylmethionine mainly through the polyamine biosynthetic pathway, where it behaves as a powerful inhibitory product. For instance, 5-Methylthioadenosine has been shown to influence the regulation of gene expression, proliferation, differentiation, and apoptosis (PMID:15313459). In humans, 5-methylthioadenosine is involved in the metabolic disorder called hypermethioninemia. Outside of the human body, 5-Methylthioadenosine has been detected, but not quantified in several different foods, such as soursops, allspices, summer grapes, alaska wild rhubarbs, and breadfruits. Elevated excretion appears in children with severe combined immunodeficiency syndrome (SCID) (PMID:3987052). Evidence suggests that 5-Methylthioadenosine can affect cellular processes in many ways. 5-Methylthioadenosine can be found in human urine. 5-deoxy-5-methylthioadenosine, also known as S-methyl-5-thioadenosine or mta, is a member of the class of compounds known as 5-deoxy-5-thionucleosides. 5-deoxy-5-thionucleosides are 5-deoxyribonucleosides in which the ribose is thio-substituted at the 5position by a S-alkyl group. 5-deoxy-5-methylthioadenosine is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). 5-deoxy-5-methylthioadenosine can be found in a number of food items such as allspice, sesame, roselle, and bayberry, which makes 5-deoxy-5-methylthioadenosine a potential biomarker for the consumption of these food products. 5-deoxy-5-methylthioadenosine can be found primarily in blood and urine, as well as in human fibroblasts, platelet and prostate tissues. 5-deoxy-5-methylthioadenosine exists in all living species, ranging from bacteria to humans. In humans, 5-deoxy-5-methylthioadenosine is involved in a couple of metabolic pathways, which include methionine metabolism and spermidine and spermine biosynthesis. 5-deoxy-5-methylthioadenosine is also involved in several metabolic disorders, some of which include glycine n-methyltransferase deficiency, methionine adenosyltransferase deficiency, homocystinuria-megaloblastic anemia due to defect in cobalamin metabolism, cblg complementation type, and hypermethioninemia. 5'-Methylthioadenosine (5'-(Methylthio)-5'-deoxyadenosine) is a nucleoside generated from S-adenosylmethionine (SAM) during polyamine synthesis[1]. 5'-Methylthioadenosine suppresses tumors by inhibiting tumor cell proliferation, invasion, and the induction of apoptosis while controlling the inflammatory micro-environments of tumor tissue. 5'-Methylthioadenosine and its associated materials have striking regulatory effects on tumorigenesis[2]. 5'-Methylthioadenosine (5'-(Methylthio)-5'-deoxyadenosine) is a nucleoside generated from S-adenosylmethionine (SAM) during polyamine synthesis[1]. 5'-Methylthioadenosine suppresses tumors by inhibiting tumor cell proliferation, invasion, and the induction of apoptosis while controlling the inflammatory micro-environments of tumor tissue. 5'-Methylthioadenosine and its associated materials have striking regulatory effects on tumorigenesis[2]. 5'-Methylthioadenosine (5'-(Methylthio)-5'-deoxyadenosine) is a nucleoside generated from S-adenosylmethionine (SAM) during polyamine synthesis[1]. 5'-Methylthioadenosine suppresses tumors by inhibiting tumor cell proliferation, invasion, and the induction of apoptosis while controlling the inflammatory micro-environments of tumor tissue. 5'-Methylthioadenosine and its associated materials have striking regulatory effects on tumorigenesis[2].

   

Homocysteine

(2S)-2-amino-4-sulfanylbutanoic acid

C4H9NO2S (135.0354)


A high level of blood serum homocysteine is a powerful risk factor for cardiovascular disease. Unfortunately, one study which attempted to decrease the risk by lowering homocysteine was not fruitful. This study was conducted on nearly 5000 Norwegian heart attack survivors who already had severe, late-stage heart disease. No study has yet been conducted in a preventive capacity on subjects who are in a relatively good state of health.; Elevated levels of homocysteine have been linked to increased fractures in elderly persons. The high level of homocysteine will auto-oxidize and react with reactive oxygen intermediates and damage endothelial cells and has a higher risk to form a thrombus. Homocysteine does not affect bone density. Instead, it appears that homocysteine affects collagen by interfering with the cross-linking between the collagen fibers and the tissues they reinforce. Whereas the HOPE-2 trial showed a reduction in stroke incidence, in those with stroke there is a high rate of hip fractures in the affected side. A trial with 2 homocysteine-lowering vitamins (folate and B12) in people with prior stroke, there was an 80\\\\\\% reduction in fractures, mainly hip, after 2 years. Interestingly, also here, bone density (and the number of falls) were identical in the vitamin and the placebo groups.; Homocysteine is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with increased incidence of cardiovascular disease and Alzheimers disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. Pyridoxal, folic acid, riboflavin, and Vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 \\\\\\%, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocysteinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD. (PMID 17136938, 15630149); Homocysteine is an amino acid with the formula HSCH2CH2CH(NH2)CO2H. It is a homologue of the amino acid cysteine, differing by an additional methylene (-CH2-) group. It is biosynthesized from methionine by the removal of its terminal C? methyl group. Homocysteine can be recycled into methionine or converted into cysteine with the aid of B-vitamins.; Studies reported in 2006 have shown that giving vitamins [folic acid, B6 and B12] to reduce homocysteine levels may not quickly offer benefit, however a significant 25\\\\\\% reduction in stroke was found in the HOPE-2 study even in patients mostly with existing serious arterial decline although the overall death rate was not significantly changed by the intervention in the trial. Clearly, reducing homocysteine does not quickly repair existing... Homocysteine (CAS: 454-29-5) is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with an increased incidence of cardiovascular disease and Alzheimers disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. It has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Pyridoxal, folic acid, riboflavin, and vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 \\\\\\%, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocystinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD (PMID: 17136938 , 15630149). Moreover, homocysteine is found to be associated with cystathionine beta-synthase deficiency, cystathioninuria, methylenetetrahydrofolate reductase deficiency, and sulfite oxidase deficiency, which are inborn errors of metabolism. [Spectral] L-Homocysteine (exact mass = 135.0354) and L-Valine (exact mass = 117.07898) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Homocysteine is biosynthesized naturally via a multi-step process.[9] First, methionine receives an adenosine group from ATP, a reaction catalyzed by S-adenosyl-methionine synthetase, to give S-adenosyl methionine (SAM-e). SAM-e then transfers the methyl group to an acceptor molecule, (e.g., norepinephrine as an acceptor during epinephrine synthesis, DNA methyltransferase as an intermediate acceptor in the process of DNA methylation). The adenosine is then hydrolyzed to yield L-homocysteine. L-Homocysteine has two primary fates: conversion via tetrahydrofolate (THF) back into L-methionine or conversion to L-cysteine.[10] Biosynthesis of cysteine Mammals biosynthesize the amino acid cysteine via homocysteine. Cystathionine β-synthase catalyses the condensation of homocysteine and serine to give cystathionine. This reaction uses pyridoxine (vitamin B6) as a cofactor. Cystathionine γ-lyase then converts this double amino acid to cysteine, ammonia, and α-ketobutyrate. Bacteria and plants rely on a different pathway to produce cysteine, relying on O-acetylserine.[11] Methionine salvage Homocysteine can be recycled into methionine. This process uses N5-methyl tetrahydrofolate as the methyl donor and cobalamin (vitamin B12)-related enzymes. More detail on these enzymes can be found in the article for methionine synthase. Other reactions of biochemical significance Homocysteine can cyclize to give homocysteine thiolactone, a five-membered heterocycle. Because of this "self-looping" reaction, homocysteine-containing peptides tend to cleave themselves by reactions generating oxidative stress.[12] Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors.[13] It has been proposed that both homocysteine and its thiolactone may have played a significant role in the appearance of life on the early Earth.[14] L-Homocysteine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=454-28-4 (retrieved 2024-06-29) (CAS RN: 6027-13-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). DL-Homocysteine is a weak neurotoxin, and can affect the production of kynurenic acid in the brain. DL-Homocysteine is a weak neurotoxin, and can affect the production of kynurenic acid in the brain. L-Homocysteine, a homocysteine metabolite, is a homocysteine that has L configuration. L-Homocysteine induces upregulation of cathepsin V that mediates vascular endothelial inflammation in hyperhomocysteinaemia[1][2].

   

Methionine

(2S)-2-amino-4-(methylsulfanyl)butanoic acid

C5H11NO2S (149.051)


Methionine (Met), also known as L-methionine, is an alpha-amino acid. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Amino acids are organic compounds that contain amino (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid. Methionine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Methionine is found in all organisms ranging from bacteria to plants to animals. It is classified as an aliphatic, non-polar amino acid. Methionine is an essential amino acid (there are 9 essential amino acids), meaning the body cannot synthesize it, and it must be obtained from the diet. It is required for normal growth and development of humans, other mammals, and avian species. In addition to being a substrate for protein synthesis, methionine is an intermediate in transmethylation reactions, serving as the major methyl group donor in vivo, including the methyl groups for DNA and RNA intermediates. Methionine is a methyl acceptor for 5-methyltetrahydrofolate-homocysteine methyltransferase (methionine synthase), the only reaction that allows for the recycling of this form of folate, and is also a methyl acceptor for the catabolism of betaine. Methionine is the metabolic precursor for cysteine. Only the sulfur atom from methionine is transferred to cysteine; the carbon skeleton of cysteine is donated by serine (PMID: 16702340 ). There is a general consensus concerning normal sulfur amino acid (SAA) requirements. WHO recommendations amount to 13 mg/kg per 24 h in healthy adults. This amount is roughly doubled in artificial nutrition regimens. In disease or after trauma, requirements may be altered for methionine, cysteine, and taurine. Although in specific cases of congenital enzyme deficiency, prematurity, or diminished liver function, hypermethioninemia or hyperhomocysteinemia may occur, SAA supplementation can be considered safe in amounts exceeding 2-3 times the minimum recommended daily intake. Apart from some very specific indications (e.g. acetaminophen poisoning) the usefulness of SAA supplementation is not yet established (PMID: 16702341 ). Methionine is known to exacerbate psychopathological symptoms in schizophrenic patients, but there is no evidence of similar effects in healthy subjects. The role of methionine as a precursor of homocysteine is the most notable cause for concern. Acute doses of methionine can lead to acute increases in plasma homocysteine, which can be used as an index of the susceptibility to cardiovascular disease. Sufficiently high doses of methionine can actually result in death. Longer-term studies in adults have indicated no adverse consequences of moderate fluctuations in dietary methionine intake, but intakes higher than 5 times the normal amount resulted in elevated homocysteine levels. These effects of methionine on homocysteine and vascular function are moderated by supplements of vitamins B-6, B-12, C, and folic acid (PMID: 16702346 ). When present in sufficiently high levels, methionine can act as an atherogen and a metabotoxin. An atherogen is a compound that when present at chronically high levels causes atherosclerosis and cardiovascular disease. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of methionine are associated with at least ten inborn errors of metabolism, including cystathionine beta-synthase deficiency, glycine N-methyltransferase deficiency, homocystinuria, tyrosinemia, galactosemia, homocystinuria-megaloblastic anemia due to defects in cobalamin metabolism, methionine adenosyltransferase deficiency, methylenetetrahydrofolate reductase deficiency, and S-adenosylhomocysteine (SAH) hydrolase deficiency. Chronically elevated levels of methionine in infants can lead to intellectual disability and othe... [Spectral] L-Methionine (exact mass = 149.05105) and Adenosine (exact mass = 267.09675) and S-Adenosyl-L-homocysteine (exact mass = 384.12159) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] L-Methionine (exact mass = 149.05105) and Tyramine (exact mass = 137.08406) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. l-Methionine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=63-68-3 (retrieved 2024-07-01) (CAS RN: 63-68-3). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Methionine is the L-isomer of Methionine, an essential amino acid for human development. Methionine acts as a hepatoprotectant. L-Methionine is the L-isomer of Methionine, an essential amino acid for human development. Methionine acts as a hepatoprotectant.

   

Methionine sulfoxide

α-amino-γ-(methylsulfinyl)-Butyric acid

C5H11NO3S (165.046)


Methionine sulfoxide belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Methionine sulfoxide exists in all living species, ranging from bacteria to humans. Within humans, methionine sulfoxide participates in a number of enzymatic reactions. In particular, methionine sulfoxide can be biosynthesized from L-methionine through its interaction with the enzyme methionine-R-sulfoxide reductase B3. In addition, methionine sulfoxide can be biosynthesized from L-methionine through the action of the enzyme methionine-R-sulfoxide reductase b2, mitochondrial. In humans, methionine sulfoxide is involved in the metabolic disorder called hypermethioninemia. Methionine sulfoxide is an oxidation product of methionine with reactive oxygen species via 2-electron-dependent mechanism. Such oxidants can be generated from activated neutrophils; therefore, methionine sulfoxide can be regarded as a biomarker of oxidative stress in vivo. (PMID 12576054) [HMDB]. Methionine sulfoxide is found in many foods, some of which are romaine lettuce, white cabbage, dill, and yellow bell pepper. L-Methionine sulfoxide (H-Met(O)-OH), a metabolite of Methionine, induces M1/classical macrophage polarization, and modulates oxidative stress and purinergic signaling parameters[1]. Methionine sulfoxide is an oxidation product of methionine with reactive oxygen species and can be regarded as a biomarker of oxidative stress in vivo. Methionine sulfoxide is an oxidation product of methionine with reactive oxygen species and can be regarded as a biomarker of oxidative stress in vivo.

   

L-Ornithine

(2S)-2,5-diaminopentanoic acid

C5H12N2O2 (132.0899)


Ornithine, also known as (S)-2,5-diaminopentanoic acid or ornithine, (L)-isomer, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. Ornithine is soluble (in water) and a moderately acidic compound (based on its pKa). Ornithine can be found in a number of food items such as pine nut, lingonberry, turnip, and cassava, which makes ornithine a potential biomarker for the consumption of these food products. Ornithine can be found primarily in most biofluids, including urine, cerebrospinal fluid (CSF), feces, and saliva, as well as throughout most human tissues. Ornithine exists in all living species, ranging from bacteria to humans. In humans, ornithine is involved in few metabolic pathways, which include arginine and proline metabolism, glycine and serine metabolism, spermidine and spermine biosynthesis, and urea cycle. Ornithine is also involved in several metabolic disorders, some of which include ornithine transcarbamylase deficiency (OTC deficiency), prolidase deficiency (PD), citrullinemia type I, and arginine: glycine amidinotransferase deficiency (AGAT deficiency). Moreover, ornithine is found to be associated with cystinuria, alzheimers disease, leukemia, and uremia. Ornithine is a non-carcinogenic (not listed by IARC) potentially toxic compound. Ornithine is a drug which is used for nutritional supplementation, also for treating dietary shortage or imbalance. it has been claimed that ornithine improves athletic performance, has anabolic effects, has wound-healing effects, and is immuno-enhancing. Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl . L-Ornithine is metabolised to L-arginine. L-arginine stimulates the pituitary release of growth hormone. Burns or other injuries affect the state of L-arginine in tissues throughout the body. As De novo synthesis of L-arginine during these conditions is usually not sufficient for normal immune function, nor for normal protein synthesis, L-ornithine may have immunomodulatory and wound-healing activities under these conditions (by virtue of its metabolism to L-arginine) (DrugBank). Chronically high levels of ornithine are associated with at least 9 inborn errors of metabolism including: Cystathionine Beta-Synthase Deficiency, Hyperornithinemia with gyrate atrophy, Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, Hyperprolinemia Type II, Lysinuric Protein Intolerance, Ornithine Aminotransferase Deficiency, Ornithine Transcarbamylase Deficiency and Prolinemia Type II (T3DB). Ornithine or L-ornithine, also known as (S)-2,5-diaminopentanoic acid is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. L-ornithine is soluble (in water) and a moderately basic compound. Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. It is considered to be a non-essential amino acid. A non-essential amino acid is an amino acid that can be synthesized from central metabolic pathway intermediates in humans and is not required in the diet. L-Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine is a central part of the urea cycle, which allows for the disposal of excess nitrogen. Outside the human body, L-ornithine is abundant in a number of food items such as wild rice, brazil nuts, common oregano, and common grapes. L-ornithine can be found throughout most human tissues; and in most biofluids, some of which include blood, urine, cerebrospinal fluid (CSF), sweat, saliva, and feces. L-ornithine exists in all living species, from bacteria to plants to humans. L-Ornithine is also a precursor of citrulline and arginine. In order for ornithine that is produced in the cytosol to be converted to citrulline, it must first cross the inner mitochondrial membrane into the mitochondrial matrix where it is carbamylated by the enzyme known as ornithine transcarbamylase. This transfer is mediated by the mitochondrial ornithine transporter (SLC25A15; AF112968; ORNT1). Mutations in the mitochondrial ornithine transporter result in hyperammonemia, hyperornithinemia, homocitrullinuria (HHH) syndrome, a disorder of the urea cycle (PMID: 16256388). The pathophysiology of the disease may involve diminished ornithine transport into mitochondria, resulting in ornithine accumulation in the cytoplasm and reduced ability to clear carbamoyl phosphate and ammonia loads (OMIM 838970). In humans, L-ornithine is involved in a number of other metabolic disorders, some of which include, ornithine transcarbamylase deficiency (OTC deficiency), argininemia, and guanidinoacetate methyltransferase deficiency (GAMT deficiency). Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. Moreover, Ornithine is found to be associated with cystinuria, hyperdibasic aminoaciduria I, and lysinuric protein intolerance, which are inborn errors of metabolism. It has been claimed that ornithine improves athletic performance, has anabolic effects, has wound-healing effects, and is immuno-enhancing. L-Ornithine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=70-26-8 (retrieved 2024-07-01) (CAS RN: 70-26-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Ornithine ((S)-2,5-Diaminopentanoic acid) is a non-proteinogenic amino acid, is mainly used in urea cycle removing excess nitrogen in vivo. L-Ornithine shows nephroprotective[1][2]. L-Ornithine ((S)-2,5-Diaminopentanoic acid) is a non-proteinogenic amino acid, is mainly used in urea cycle removing excess nitrogen in vivo. L-Ornithine shows nephroprotective[1][2].

   

S-adenosylhomocysteine (SAH)

(2S)-2-Amino-4-({[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxytetrahydrofuran-2-yl]methyl}sulphanyl)butanoic acid

C14H20N6O5S (384.1216)


S-Adenosyl-L-homocysteine (SAH) is formed by the demethylation of S-adenosyl-L-methionine. S-Adenosylhomocysteine (AdoHcy or SAH) is also the immediate precursor of all of the homocysteine produced in the body. The reaction is catalyzed by S-adenosylhomocysteine hydrolase and is reversible with the equilibrium favoring formation of SAH. In vivo, the reaction is driven in the direction of homocysteine formation by the action of the enzyme adenosine deaminase which converts the second product of the S-adenosylhomocysteine hydrolase reaction, adenosine, to inosine. Except for methyl transfer from betaine and from methylcobalamin in the methionine synthase reaction, SAH is the product of all methylation reactions that involve S-adenosylmethionine (SAM) as the methyl donor. Methylation is significant in epigenetic regulation of protein expression via DNA and histone methylation. The inhibition of these SAM-mediated processes by SAH is a proven mechanism for metabolic alteration. Because the conversion of SAH to homocysteine is reversible, with the equilibrium favoring the formation of SAH, increases in plasma homocysteine are accompanied by an elevation of SAH in most cases. Disturbances in the transmethylation pathway indicated by abnormal SAH, SAM, or their ratio have been reported in many neurodegenerative diseases, such as dementia, depression, and Parkinsons disease (PMID:18065573, 17892439). Therefore, when present in sufficiently high levels, S-adenosylhomocysteine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of S-adenosylhomocysteine are associated with S-adenosylhomocysteine (SAH) hydrolase deficiency and adenosine deaminase deficiency. S-Adenosylhomocysteine forms when there are elevated levels of homocysteine and adenosine. S-Adenosyl-L-homocysteine is a potent inhibitor of S-adenosyl-L-methionine-dependent methylation reactions. It is toxic to immature lymphocytes and can lead to immunosuppression (PMID:221926). S-adenosylhomocysteine, also known as adohcy or sah, is a member of the class of compounds known as 5-deoxy-5-thionucleosides. 5-deoxy-5-thionucleosides are 5-deoxyribonucleosides in which the ribose is thio-substituted at the 5position by a S-alkyl group. S-adenosylhomocysteine is slightly soluble (in water) and a moderately acidic compound (based on its pKa). S-adenosylhomocysteine can be found in a number of food items such as rapini, european plum, rambutan, and pepper (c. pubescens), which makes S-adenosylhomocysteine a potential biomarker for the consumption of these food products. S-adenosylhomocysteine can be found primarily in blood, cerebrospinal fluid (CSF), feces, and urine, as well as throughout most human tissues. S-adenosylhomocysteine exists in all living species, ranging from bacteria to humans. In humans, S-adenosylhomocysteine is involved in several metabolic pathways, some of which include phosphatidylcholine biosynthesis PC(14:0/18:3(9Z,12Z,15Z)), phosphatidylcholine biosynthesis PC(22:4(7Z,10Z,13Z,16Z)/22:0), phosphatidylcholine biosynthesis PC(20:3(5Z,8Z,11Z)/22:2(13Z,16Z)), and phosphatidylcholine biosynthesis PC(18:3(6Z,9Z,12Z)/22:5(7Z,10Z,13Z,16Z,19Z)). S-adenosylhomocysteine is also involved in several metabolic disorders, some of which include 3-phosphoglycerate dehydrogenase deficiency, hawkinsinuria, non ketotic hyperglycinemia, and tyrosine hydroxylase deficiency. Moreover, S-adenosylhomocysteine is found to be associated with neurodegenerative disease and parkinsons disease. S-adenosylhomocysteine is a non-carcinogenic (not listed by IARC) potentially toxic compound. S-Adenosyl-L-homocysteine (SAH) is an amino acid derivative used in several metabolic pathways in most organisms. It is an intermediate in the synthesis of cysteine and adenosine . [Spectral] S-Adenosyl-L-homocysteine (exact mass = 384.12159) and Adenosine (exact mass = 267.09675) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] S-Adenosyl-L-homocysteine (exact mass = 384.12159) and Cytidine (exact mass = 243.08552) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Acquisition and generation of the data is financially supported in part by CREST/JST. COVID info from PDB, Protein Data Bank, WikiPathways Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS SAH (S-Adenosylhomocysteine) is an amino acid derivative and a modulartor in several metabolic pathways. It is an intermediate in the synthesis of cysteine and adenosine[1]. SAH is an inhibitor for METTL3-METTL14 heterodimer complex (METTL3-14) with an IC50 of 0.9 μM[2]. SAH (S-Adenosylhomocysteine) is an amino acid derivative and a modulartor in several metabolic pathways. It is an intermediate in the synthesis of cysteine and adenosine[1]. SAH is an inhibitor for METTL3-METTL14 heterodimer complex (METTL3-14) with an IC50 of 0.9 μM[2].

   

Choline

(2-hydroxyethyl)trimethylazanium

[C5H14NO]+ (104.1075)


Choline is a basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism. Choline is now considered to be an essential vitamin. While humans can synthesize small amounts (by converting phosphatidylethanolamine to phosphatidylcholine), it must be consumed in the diet to maintain health. Required levels are between 425 mg/day (female) and 550 mg/day (male). Milk, eggs, liver, and peanuts are especially rich in choline. Most choline is found in phospholipids, namely phosphatidylcholine or lecithin. Choline can be oxidized to form betaine, which is a methyl source for many reactions (i.e. conversion of homocysteine into methionine). Lack of sufficient amounts of choline in the diet can lead to a fatty liver condition and general liver damage. This arises from the lack of VLDL, which is necessary to transport fats away from the liver. Choline deficiency also leads to elevated serum levels of alanine amino transferase and is associated with increased incidence of liver cancer. Nutritional supplement. Occurs free and combined in many animal and vegetable foods with highest concentrations found in egg yolk, meat, fish, milk, cereaks and legumes Choline. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=62-49-7 (retrieved 2024-06-29) (CAS RN: 62-49-7). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).

   

S-Adenosylmethioninamine

{[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl}(3-aminopropyl)methylsulfanium

C14H23N6O3S+ (355.1552)


S-Adenosylmethioninamine is a biological sulfonium compound known as the major biological methyl donor. It is also a donor of methylene groups, amino groups, ribosyl groups and aminopropyl groups (PMID 15130560). S-Adenosylmethioninamine is a prodcut of enzyme adenosylmethionine decarboxylase [EC 4.1.1.50] in methionine metabolism pathway (KEGG). [HMDB] S-Adenosylmethioninamine is a biological sulfonium compound known as the major biological methyl donor. It is also a donor of methylene groups, amino groups, ribosyl groups and aminopropyl groups (PMID 15130560). S-Adenosylmethioninamine is a prodcut of enzyme adenosylmethionine decarboxylase [EC 4.1.1.50] in methionine metabolism pathway (KEGG).

   

5-Methylthioribose 1-phosphate

{[(2R,3R,4S,5S)-3,4-dihydroxy-5-[(methylsulfanyl)methyl]oxolan-2-yl]oxy}phosphonic acid

C6H13O7PS (260.012)


5-Methylthioribose 1-phosphate belongs to the class of organic compounds known as pentoses. These are monosaccharides in which the carbohydrate moiety contains five carbon atoms. 5-Methylthioribose 1-phosphate is an intermediate in methionine biosynthesis. It is converted from 5-deoxy-5-methylthioadenosine by 5-deoxy-5-methylthioadenosine phosphorylase. Then it is converted to methionine (PMID: 2153115). In the methionine salvage pathway, 5-methylthioribose 1-phosphate isomerase (M1Pi) catalyzes the conversion of 5-methylthioribose 1-phosphate (MTR-1-P) into 5-methylthioribulose 1-phosphate (MTRu-1-P). 5-Methylthioribose 1-phosphate is an intermediate in methionine biosynthesis. It is converted from 5-Deoxy-5-methylthioadenosine by 5-Deoxy-5-methylthioadenosine phosphorylase. Then it is converted to methionine (PMID 2153115). In the methionine salvage pathway 5-methylthioribose 1-phosphate isomerase (M1Pi) catalyzes the conversion of 5-methylthioribose 1-phosphate (MTR-1-P) to 5-methylthioribulose 1-phosphate (MTRu-1-P) [HMDB]

   

S-methyl-5-thio-D-ribulose 1-phosphate(2-)

{[3,4-dihydroxy-5-(methylsulphanyl)-2-oxopentyl]oxy}phosphonic acid

C6H13O7PS (260.012)


S-methyl-5-thio-D-ribulose 1-phosphate(2-) is also known as 1-phospho-5-S-Methylthioribulose or 1-PMT-Ribulose. S-methyl-5-thio-D-ribulose 1-phosphate(2-) is considered to be soluble (in water) and acidic

   

3-Methylthiopropionic acid

3-Methylthiopropionate sodium salt

C4H8O2S (120.0245)


3-methylthiopropionate is one of the metabolites of methionine (especially of D-methionine) and pharmacokinetics of 3-MTP in urine seems to contribute to the clinicopathological investigation of the liver cirrhosis. (PMID 3997054) [HMDB] 3-methylthiopropionate is one of the metabolites of methionine (especially of D-methionine) and pharmacokinetics of 3-MTP in urine seems to contribute to the clinicopathological investigation of the liver cirrhosis. (PMID 3997054). 3-(Methylthio)propionic acid is an intermediate in the methionine metabolism.

   

1,2-Dihydroxy-3-keto-5-methylthiopentene

(1Z)-1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one

C6H10O3S (162.0351)


At physiological pH, this molecule, 1,2-dihydroxy-3-keto-5-methylthiopentene, is a monoanion, 1,2-dihydroxy-3-keto-5-methylthiopentene anion. 1,2-dihydroxy-3-keto-5-methylthiopentene anion, an aci-reductone, is believed to be an unstable intermediate in the methionine salvage pathway in Klebsiella pneumoniae. (MetaCyc).

   

5-(Methylthio)-2,3-dioxopentyl phosphate

{[5-(methylsulfanyl)-2,3-dioxopentyl]oxy}phosphonic acid

C6H11O6PS (242.0014)


5-(Methylthio)-2,3-dioxopentyl phosphate, also known as 1-phospho-2,3-diketo-5-S-methylthiopentane or 2,3-diketo-5-methylthiopentyl-1-phosphate (DK-MTP-1-P), belongs to the class of organic compounds known as monoalkyl phosphates. These are organic compounds containing a phosphate group that is linked to exactly one alkyl chain. 5-(Methylthio)-2,3-dioxopentyl phosphate is slightly soluble (in water) and a moderately acidic compound (based on its pKa). 5-(Methylthio)-2,3-dioxopentyl phosphate exists in all eukaryotes, ranging from yeast to humans. 5-(Methylthio)-2,3-dioxopentyl phosphate is a metabolite involved in the cysteine and methionine metabolism pathway. It is a substrate for both E1 enolase-phosphatase and methylthioribulose-1-phosphate dehydratase. Outside of the human body, 5-(methylthio)-2,3-dioxopentyl phosphate can be found in a number of food items such as lime, pineapple, spearmint, and yautia. This makes 5-(methylthio)-2,3-dioxopentyl phosphate a potential biomarker for the consumption of these food products. 5-(methylthio)-2,3-dioxopentyl phosphate, also known as 1-phospho-2,3-diketo-5-S-methylthiopentane or 2,3-diketo-5-methylthio-1-phosphopentane, is a member of the class of compounds known as monoalkyl phosphates. Monoalkyl phosphates are organic compounds containing a phosphate group that is linked to exactly one alkyl chain. 5-(methylthio)-2,3-dioxopentyl phosphate is slightly soluble (in water) and a moderately acidic compound (based on its pKa). 5-(methylthio)-2,3-dioxopentyl phosphate can be found in a number of food items such as narrowleaf cattail, kumquat, ginseng, and gooseberry, which makes 5-(methylthio)-2,3-dioxopentyl phosphate a potential biomarker for the consumption of these food products. 5-(methylthio)-2,3-dioxopentyl phosphate exists in all eukaryotes, ranging from yeast to humans.

   

Betaine

(carboxymethyl)trimethylazanium

C5H11NO2 (117.079)


Betaine (CAS: 107-43-7), also known as N,N,N-trimethylglycine, was named after its discovery in sugar beet (Beta vulgaris) in the 19th century. It is a small N-trimethylated amino acid, existing in zwitterionic form at neutral pH. It is now often called glycine betaine to distinguish it from other betaines that are widely distributed in microorganisms, plants, and animals. Many naturally occurring betaines serve as organic osmolytes, substances synthesized or taken up from the environment by cells for protection against osmotic stress, drought, high salinity, or high temperature. Intracellular accumulation of betaines permits water retention in cells, thus protecting from the effects of dehydration (Wikipedia). Betaine functions as a methyl donor in that it carries and donates methyl functional groups to facilitate necessary chemical processes. In particular, it methylates homocysteine to methionine, also producing N,N-dimethylglycine. The donation of methyl groups is important to proper liver function, cellular replication, and detoxification reactions. Betaine also plays a role in the manufacture of carnitine and serves to protect the kidneys from damage. Betaine comes from either the diet or by the oxidation of choline. Betaine insufficiency is associated with metabolic syndrome, lipid disorders, and diabetes, and may have a role in vascular and other diseases (PMID: 20346934). Betaine is important in development, from the pre-implantation embryo to infancy. Betaine is also widely regarded as an anti-oxidant. Betaine has been shown to have an inhibitory effect on NO release in activated microglial cells and may be an effective therapeutic component to control neurological disorders (PMID: 22801281). As a drug, betaine hydrochloride has been used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also been used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and for gastrointestinal disturbances (Martindale, The Extra Pharmacopoeia, 30th Ed, p1341). Betaine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=107-43-7 (retrieved 2024-07-01) (CAS RN: 107-43-7). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).

   

S-Adenosylmethionine

[(3S)-3-amino-3-carboxypropyl]({[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl})methylsulfanium

C15H22N6O5S (398.1372)


S-adenosylmethionine, also known as sam or adomet, is a member of the class of compounds known as 5-deoxy-5-thionucleosides. 5-deoxy-5-thionucleosides are 5-deoxyribonucleosides in which the ribose is thio-substituted at the 5position by a S-alkyl group. S-adenosylmethionine is slightly soluble (in water) and a moderately acidic compound (based on its pKa). S-adenosylmethionine can be found in a number of food items such as common grape, half-highbush blueberry, jerusalem artichoke, and thistle, which makes S-adenosylmethionine a potential biomarker for the consumption of these food products. S-adenosylmethionine can be found primarily in blood, cerebrospinal fluid (CSF), feces, and urine, as well as throughout most human tissues. S-adenosylmethionine exists in all eukaryotes, ranging from yeast to humans. In humans, S-adenosylmethionine is involved in several metabolic pathways, some of which include phosphatidylcholine biosynthesis PC(22:1(13Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), phosphatidylcholine biosynthesis PC(22:0/18:3(9Z,12Z,15Z)), phosphatidylcholine biosynthesis PC(24:0/24:0), and phosphatidylcholine biosynthesis PC(20:5(5Z,8Z,11Z,14Z,17Z)/20:0). S-adenosylmethionine is also involved in several metabolic disorders, some of which include methylenetetrahydrofolate reductase deficiency (MTHFRD), 3-phosphoglycerate dehydrogenase deficiency, monoamine oxidase-a deficiency (MAO-A), and aromatic l-aminoacid decarboxylase deficiency. Moreover, S-adenosylmethionine is found to be associated with diabetes mellitus type 2 and neurodegenerative disease. S-adenosylmethionine is a non-carcinogenic (not listed by IARC) potentially toxic compound. S-Adenosyl methionine is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throughout the body, most SAM-e is produced and consumed in the liver. More than 40 methyl transfers from SAM-e are known, to various substrates such as nucleic acids, proteins, lipids and secondary metabolites. It is made from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase (EC 2.5.1.6). SAM was first discovered by Giulio Cantoni in 1952 . Significant first-pass metabolism in the liver. Approximately 50\\\% of S-Adenosylmethionine (SAMe) is metabolized in the liver. SAMe is metabolized to S-adenosylhomocysteine, which is then metabolized to homocysteine. Homocysteine can either be metabolized to cystathionine and then cysteine or to methionine. The cofactor in the metabolism of homocysteine to cysteine is vitamin B6. Cofactors for the metabolism of homocysteine to methionine are folic acid, vitamin B12 and betaine (T3DB). S-Adenosylmethionine (CAS: 29908-03-0), also known as SAM or AdoMet, is a physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in the treatment of chronic liver disease (From Merck, 11th ed). S-Adenosylmethionine is a natural substance present in the cells of the body. It plays a crucial biochemical role by donating a one-carbon methyl group in a process called transmethylation. S-Adenosylmethionine, formed from the reaction of L-methionine and adenosine triphosphate catalyzed by the enzyme S-adenosylmethionine synthetase, is the methyl-group donor in the biosynthesis of both DNA and RNA nucleic acids, phospholipids, proteins, epinephrine, melatonin, creatine, and other molecules.