Reaction Process: WikiPathways:WP1589
Folate-alcohol and cancer pathway hypotheses related metabolites
find 10 related metabolites which is associated with chemical reaction(pathway) Folate-alcohol and cancer pathway hypotheses
Cysteine ⟶ Cystathionine
5-Methyltetrahydrofolic acid
5 methyltetrahydrofolic acid (5-MTHF) is the most biologically active form of the B-vitamin known as folic acid, also known generically as folate. 5-MTHF functions, in concert with vitamin B12, as a methyl-group donor involved in the conversion of the amino acid homocysteine to methionine. Methyl (CH3) group donation is vital to many bodily processes, including serotonin, melatonin, and DNA synthesis. Therapeutically, 5-MTHF is instrumental in reducing homocysteine levels, preventing neural tube defects, and improving vascular endothelial function. Research on folate supplementation suggests it plays a key role in preventing cervical dysplasia and protecting against neoplasia in ulcerative colitis. Folic acid also shows promise as part of a nutritional protocol to treat vitiligo, and may reduce inflammation of the gingiva. Furthermore, certain neurological, cognitive, and psychiatric presentations may be secondary to folate deficiency. Such presentations include depression, peripheral neuropathy, myelopathy, restless legs syndrome, insomnia, dementia, forgetfulness, irritability, endogenous depression, organic psychosis, and schizophrenia-like syndromes. After ingestion, the process of conversion of folic acid to the metabolically active coenzyme forms is relatively complex. Synthesis of the active forms of folic acid requires several enzymes, adequate liver and intestinal function, and adequate supplies of riboflavin (B2), niacin (B3), pyridoxine (B6), zinc, vitamin C, and serine. After formation of the coenzyme forms of the vitamin in the liver, these metabolically active compounds are secreted into the small intestine with bile (the folate enterohepatic cycle), where they are reabsorbed and distributed to tissues throughout the body. Human pharmacokinetic studies indicate folic acid has high bioavailability, with large oral doses of folic acid substantially raising plasma levels in healthy subjects in a time and dose dependent manner. Red blood cells (RBCs) appear to be the storage depot for folic acid, as RBC levels remain elevated for periods in excess of 40 days following discontinuation of supplementation. Folic acid is poorly transported to the brain and rapidly cleared from the central nervous system. The primary methods of elimination of absorbed folic acid are fecal (through bile) and urinary. Despite the biochemical complexity of this process, evidence suggests oral supplementation with folic acid increases the bodys pool of 5-MTHF in healthy individuals. However, enzyme defects, mal-absorption, digestive system pathology, and liver disease can result in impaired ability to activate folic acid. In fact, some individuals have a severe congenital deficiency of the enzyme Methyl tetrahydrofolate reductase (5-MTHFR), which is needed to convert folic acid to 5-MTHF. Milder forms of this enzyme defect likely interact with dietary folate status to determine risk for some disease conditions. In individuals with a genetic defect of this enzyme (whether mild or severe), supplementation with 5- MTHF might be preferable to folic acid supplementation. (PMID: 17176169). 5 methyltetrahydrofolic acid (5-MTHF) is the most biologically active form of the B-vitamin folic acid, also known generically as folate. 5-MTHF functions, in concert with vitamin B12, as a methyl-group donor involved in the conversion of the amino acid homocysteine to methionine. Methyl (CH3) group donation is vital to many bodily processes, including serotonin, melatonin, and DNA synthesis. Therapeutically, 5-MTHF is instrumental in reducing homocysteine levels, preventing neural tube defects, and improving vascular endothelial function. Research on folate supplementation suggests it plays a key role in preventing cervical dysplasia and protecting against neoplasia in ulcerative colitis. Folic acid also shows promise as part of a nutritional protocol to treat vitiligo, and may reduce inflammation of the gingiva. Furthermore, certain neurological, cognitive, and psychiatric presentations may be secondary to folate deficiency. Such presentations include depression, peripheral neuropathy, myelopathy, restless legs syndrome, insomnia, dementia, forgetfulness, irritability, endogenous depression, organic psychosis, and schizophrenia-like syndromes. After ingestion, the process of conversion of folic acid to the metabolically active coenzyme forms is relatively complex. Synthesis of the active forms of folic acid requires several enzymes, adequate liver and intestinal function, and adequate supplies of riboflavin (B2), niacin (B3), pyridoxine (B6), zinc, vitamin C, and serine. After formation of the coenzyme forms of the vitamin in the liver, these metabolically active compounds are secreted into the small intestine with bile (the folate enterohepatic cycle), where they are reabsorbed and distributed to tissues throughout the body. Human pharmacokinetic studies indicate folic acid has high bioavailability, with large oral doses of folic acid substantially raising plasma levels in healthy subjects in a time and dose dependent manner. Red blood cells (RBCs) appear to be the storage depot for folic acid, as RBC levels remain elevated for periods in excess of 40 days following discontinuation of supplementation. Folic acid is poorly transported to the brain and rapidly cleared from the central nervous system. The primary methods of elimination of absorbed folic acid are fecal (through bile) and urinary. Despite the biochemical complexity of this process, evidence suggests oral supplementation with folic acid increases the bodys pool of 5-MTHF in healthy individuals. However, enzyme defects, mal-absorption, digestive system pathology, and liver disease can result in impaired ability to activate folic acid. In fact, some individuals have a severe congenital deficiency of the enzyme Methyl tetrahydrofolate reductase (5-MTHFR), which is needed to convert folic acid to 5-MTHF. Milder forms of this enzyme defect likely interact with dietary folate status to determine risk for some disease conditions. In individuals with a genetic defect of this enzyme (whether mild or severe), supplementation with 5- MTHF might be preferable to folic acid supplementation. (PMID: 17176169) [HMDB] 5-Methyltetrahydrofolic acid (5-Methyl THF) is a biologically active form of folic acid. 5-Methyltetrahydrofolic acid is a methylated derivate of tetrahydrofolate. 5-Methyltetrahydrofolic acid is the predominant natural dietary folate and the principal form of folate in plasma and cerebrospinal fluid[1]. Levomefolic acid (5-MTHF) is an orally active, brain-penetrant natural active form of folic acid and is one of the most widely used folic acid food supplements[1][2].
L-Cystathionine
Cystathionine is a dipeptide formed by serine and homocysteine. Cystathioninuria is a prominent manifestation of vitamin-B6 deficiency. The transsulfuration of methionine yields homocysteine, which combines with serine to form cystathionine, the proximate precursor of cysteine through the enzymatic activity of cystathionase. In conditions in which cystathionine gamma-synthase or cystathionase is deficient, for example, there is cystathioninuria. Although cystathionine has not been detected in normal human serum or plasma by most conventional methods, gas chromatographic/mass spectrometric methodology detected a mean concentration of cystathionine in normal human serum of 140 nM, with a range of 65 to 301 nM. Cystathionine concentrations in CSF have been 10, 1, and 0.5 uM, and "not detected". Only traces (i.e., <1 uM) of cystathionine are present in normal CSF.587. Gamma-cystathionase deficiency (also known as Cystathioninuria), which is an autosomal recessive disorder (NIH: 2428), provided the first instance in which, in a human, the major biochemical abnormality due to a defined enzyme defect was clearly shown to be alleviated by administration of large doses of pyridoxine. The response in gamma-cystathionase-deficient patients is not attributable to correction of a preexisting deficiency of this vitamin (OMMBID, Chap. 88). Isolated from Phallus impudicus (common stinkhorn) CONFIDENCE standard compound; INTERNAL_ID 146 KEIO_ID C019; [MS2] KO008910 KEIO_ID C047 KEIO_ID C019 Acquisition and generation of the data is financially supported in part by CREST/JST. CONFIDENCE standard compound; ML_ID 30 L-Cystathionine is a nonprotein thioether and is a key amino acid associated with the metabolic state of sulfur-containing amino acids. L-Cystathionine protects against Homocysteine-induced mitochondria-dependent apoptosis of vascular endothelial cells (HUVECs). L-Cystathionine plays an important role in cardiovascular protection[1][2]. L-Cystathionine is a nonprotein thioether and is a key amino acid associated with the metabolic state of sulfur-containing amino acids. L-Cystathionine protects against Homocysteine-induced mitochondria-dependent apoptosis of vascular endothelial cells (HUVECs). L-Cystathionine plays an important role in cardiovascular protection[1][2].
Homocysteine
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].
L-Methionine
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.
S-adenosylhomocysteine (SAH)
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].
L-Cysteine
Cysteine (Cys), also known as L-cysteine 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. L-alanine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Cysteine is found in all organisms ranging from bacteria to plants to animals. It is classified as an aliphatic, non-polar, sulfur-containing amino acid. Cysteine is an important source of sulfur in human metabolism, and although it is classified as a non-essential amino acid, cysteine may be essential for infants, the elderly, and individuals with certain metabolic disease or who suffer from malabsorption syndromes. Cysteine can occasionally be considered as an essential or conditionally essential amino acid. Cysteine is unique amongst the twenty natural amino acids as it contains a thiol group. Thiol groups can undergo oxidation/reduction (redox) reactions; when cysteine is oxidized it can form cystine, which is two cysteine residues joined by a disulfide bond. This reaction is reversible since the reduction of this disulphide bond regenerates two cysteine molecules. The disulphide bonds of cystine are crucial to defining the structures of many proteins. Cysteine is often involved in electron-transfer reactions, and help the enzyme catalyze its reaction. Cysteine is also part of the antioxidant glutathione. N-Acetyl-L-cysteine (NAC) is a form of cysteine where an acetyl group is attached to cysteines nitrogen atom and is sold as a dietary supplement. Cysteine is named after cystine, which comes from the Greek word kustis meaning bladder (cystine was first isolated from kidney stones). Oxidation of cysteine can produce a disulfide bond with another thiol and further oxidation can produce sulphfinic or sulfonic acids. The cysteine thiol group is also a nucleophile and can undergo addition and substitution reactions. Thiol groups become much more reactive when they are ionized, and cysteine residues in proteins have pKa values close to neutrality, so they are often in their reactive thiolate form in the cell. The thiol group also has a high affinity for heavy metals and proteins containing cysteine will bind metals such as mercury, lead, and cadmium tightly. Due to this ability to undergo redox reactions, cysteine has antioxidant properties. Cysteine is important in energy metabolism. As cystine, it is a structural component of many tissues and hormones. Cysteine has clinical uses ranging from treating baldness to psoriasis to preventing smokers hack. In some cases, oral cysteine therapy has proved excellent for treatment of asthmatics, enabling them to stop theophylline and other medications. Cysteine also enhances the effect of topically applied silver, tin, and zinc salts in preventing dental cavities. In the future, cysteine may play a role in the treatment of cobalt toxicity, diabetes, psychosis, cancer, and seizures (http://www.dcnutrition.com/AminoAcids/). Cysteine has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). [Spectral] L-Cysteine (exact mass = 121.01975) and D-2-Aminobutyrate (exact mass = 103.06333) 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-Cysteine (exact mass = 121.01975) and Creatine (exact mass = 131.06948) 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. Detoxicant, dietary supplement, dough strengthener, yeast nutrient for leavened bakery products. Flavouring agent. Enzymic browning inhibitor. L-Cysteine is found in many foods, some of which are bilberry, mugwort, cowpea, and sweet bay. L-(+)-Cysteine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=52-90-4 (retrieved 2024-07-01) (CAS RN: 52-90-4). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Cysteine is a conditionally essential amino acid, which acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), glutathione and taurine. L-Cysteine suppresses ghrelin and reduces appetite in rodents and humans[1]. L-Cysteine is a conditionally essential amino acid, which acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), glutathione and taurine. L-Cysteine suppresses ghrelin and reduces appetite in rodents and humans[1].
Acetaldehyde
Acetaldehyde, also known as ethanal, belongs to the class of organic compounds known as short-chain aldehydes. These are an aldehyde with a chain length containing between 2 and 5 carbon atoms. Acetaldehyde exists in all living species, ranging from bacteria to humans. Within humans, acetaldehyde participates in a number of enzymatic reactions. In particular, acetaldehyde can be biosynthesized from ethanol which is mediated by the enzyme alcohol dehydrogenase 1B. Acetaldehyde can also be converted to acetic acid by the enzyme aldehyde dehydrogenase (mitochondrial) and aldehyde dehydrogenase X (mitochondrial). The main method of production is the oxidation of ethylene by the Wacker process, which involves oxidation of ethylene using a homogeneous palladium/copper system: 2 CH2CH2 + O2 → 2 CH3CHO. In the 1970s, the world capacity of the Wacker-Hoechst direct oxidation process exceeded 2 million tonnes annually. In humans, acetaldehyde is involved in disulfiram action pathway. Acetaldehyde is an aldehydic, ethereal, and fruity tasting compound. Outside of the human body, acetaldehyde is found, on average, in the highest concentration in a few different foods, such as sweet oranges, pineapples, and mandarin orange (clementine, tangerine) and in a lower concentration in . acetaldehyde has also been detected, but not quantified in several different foods, such as malabar plums, malus (crab apple), rose hips, natal plums, and medlars. This could make acetaldehyde a potential biomarker for the consumption of these foods. In condensation reactions, acetaldehyde is prochiral. Acetaldehyde is formally rated as a possible carcinogen (by IARC 2B) and is also a potentially toxic compound. Acetaldehyde has been found to be associated with several diseases such as alcoholism, ulcerative colitis, nonalcoholic fatty liver disease, and crohns disease; also acetaldehyde has been linked to the inborn metabolic disorders including aldehyde dehydrogenase deficiency (III) sulfate is used to reoxidize the mercury back to the mercury. Acetaldehyde was first observed by the Swedish pharmacist/chemist Carl Wilhelm Scheele (1774); it was then investigated by the French chemists Antoine François, comte de Fourcroy and Louis Nicolas Vauquelin (1800), and the German chemists Johann Wolfgang Döbereiner (1821, 1822, 1832) and Justus von Liebig (1835). At room temperature, acetaldehyde (CH3CHO) is more stable than vinyl alcohol (CH2CHOH) by 42.7 kJ/mol: Overall the keto-enol tautomerization occurs slowly but is catalyzed by acids. The level at which an average consumer could detect acetaldehyde is still considerably lower than any toxicity. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. Acetaldehyde is also created by thermal degradation or ultraviolet photo-degradation of some thermoplastic polymers during or after manufacture. The water industry generally recognizes 20–40 ppb as the taste/odor threshold for acetaldehyde. The level at which an average consumer could detect acetaldehyde is still considerably lower than any toxicity. Flavouring agent and adjuvant used to impart orange, apple and butter flavours; component of food flavourings added to milk products, baked goods, fruit juices, candy, desserts and soft drinks [DFC]
5,10-Methylene-THF
5,10-Methylene-THF is an intermediate in glycine, serine and threonine metabolism and one carbon metabolism. 5,10-CH2-THF can also be used as a coenzyme in the biosynthesis of thymidine. More specifically it is the C1-donor in the reactions catalyzed by thymidylate synthase and thymidylate synthase (FAD). It also acts as a coenzyme in the synthesis of serine from glycine via the enzyme serine hydroxymethyl transferase. 5,10-Methylene-THF is a substrate for Methylenetetrahydrofolate reductase. This enzyme converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. This reaction is required for the multistep process that converts the amino acid homocysteine to methionine. The body uses methionine to make proteins and other important compounds. 5,10-CH2-THF is a substrate for many enzymes including Bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase (mitochondrial), Aminomethyltransferase (mitochondrial), Serine hydroxymethyltransferase (mitochondrial), Methylenetetrahydrofolate reductase, C-1-tetrahydrofolate synthase (cytoplasmic), Serine hydroxymethyltransferase (cytosolic) and Thymidylate synthase. 5,10-Methylene-THF is an intermediate in the metabolism of Methane and the metabolism of Nitrogen. It is a substrate for Bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase (mitochondrial), Aminomethyltransferase (mitochondrial), Serine hydroxymethyltransferase (mitochondrial), Methylenetetrahydrofolate reductase, C-1-tetrahydrofolate synthase (cytoplasmic), Serine hydroxymethyltransferase (cytosolic) and Thymidylate synthase. [HMDB] COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Ethanol
Ethanol is a clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in alcoholic beverages. Indeed, ethanol has widespread use as a solvent of substances intended for human contact or consumption, including scents, flavorings, colorings, and medicines. Ethanol has a depressive effect on the central nervous system and because of its psychoactive effects, it is considered a drug. Ethanol has a complex mode of action and affects multiple systems in the brain, most notably it acts as an agonist to the GABA receptors. Death from ethanol consumption is possible when blood alcohol level reaches 0.4\\%. A blood level of 0.5\\% or more is commonly fatal. Levels of even less than 0.1\\% can cause intoxication, with unconsciousness often occurring at 0.3-0.4 \\%. Ethanol is metabolized by the body as an energy-providing carbohydrate nutrient, as it metabolizes into acetyl CoA, an intermediate common with glucose metabolism, that can be used for energy in the citric acid cycle or for biosynthesis. Ethanol within the human body is converted into acetaldehyde by alcohol dehydrogenase and then into acetic acid by acetaldehyde dehydrogenase. The product of the first step of this breakdown, acetaldehyde, is more toxic than ethanol. Acetaldehyde is linked to most of the clinical effects of alcohol. It has been shown to increase the risk of developing cirrhosis of the liver,[77] multiple forms of cancer, and alcoholism. Industrially, ethanol is produced both as a petrochemical, through the hydration of ethylene, and biologically, by fermenting sugars with yeast. Small amounts of ethanol are endogenously produced by gut microflora through anaerobic fermentation. However most ethanol detected in biofluids and tissues likely comes from consumption of alcoholic beverages. Absolute ethanol or anhydrous alcohol generally refers to purified ethanol, containing no more than one percent water. Absolute alcohol is not intended for human consumption. It often contains trace amounts of toxic benzene (used to remove water by azeotropic distillation). Consumption of this form of ethanol can be fatal over a short time period. Generally absolute or pure ethanol is used as a solvent for lab and industrial settings where water will disrupt a desired reaction. Pure ethanol is classed as 200 proof in the USA and Canada, equivalent to 175 degrees proof in the UK system. Ethanol is a general biomarker for the consumption of alcohol. Ethanol is also a metabolite of Hansenula and Saccharomyces (PMID: 14613880) (https://ac.els-cdn.com/S0079635206800470/1-s2.0-S0079635206800470-main.pdf?_tid=4d340044-3230-4141-88dd-deec4d2e35bd&acdnat=1550288012_0c4a20fe963843426147979d376cf624). Intoxicating constituent of all alcoholic beverages. It is used as a solvent and vehicle for food dressings and flavourings. Antimicrobial agent, e.g for pizza crusts prior to baking. extraction solvent for foodstuffs. Widely distributed in fruits and other foods V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AZ - Nerve depressants V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AB - Antidotes D - Dermatologicals > D08 - Antiseptics and disinfectants > D08A - Antiseptics and disinfectants D002491 - Central Nervous System Agents > D002492 - Central Nervous System Depressants C78272 - Agent Affecting Nervous System > C29756 - Sedative and Hypnotic D000890 - Anti-Infective Agents D012997 - Solvents
Acetate
A monocarboxylic acid anion resulting from the removal of a proton from the carboxy group of acetic acid. Acetate, also known as acetic acid or ethanoate, is a member of the class of compounds known as carboxylic acids. Carboxylic acids are compounds containing a carboxylic acid group with the formula -C(=O)OH. Acetate is soluble (in water) and a weakly acidic compound (based on its pKa). Acetate can be found in a number of food items such as pitanga, soursop, green bean, and beech nut, which makes acetate a potential biomarker for the consumption of these food products. Acetate is a non-carcinogenic (not listed by IARC) potentially toxic compound. An acetate is a salt formed by the combination of acetic acid with an alkaline, earthy, or metallic base. "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula C2H3O2−. The neutral molecules formed by the combination of the acetate ion and a positive ion (called a cation) are also commonly called "acetates" (hence, acetate of lead, acetate of aluminum, etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion CH3CO2−, or CH3COO− . In cases of skin or eye exposure, the area should be flushed with water and burns covered with dry, sterile dressings after decontamination. If ingested, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution. Watch for signs of respiratory insufficiency and assist respiration if necessary (A569) (T3DB).
