Reaction Process: BioCyc:CALBI_PWY-801

cysteine and homocysteine interconversion related metabolites

find 9 related metabolites which is associated with chemical reaction(pathway) cysteine and homocysteine interconversion

H2O + cystathionine ⟶ 2-oxobutanoate + L-cysteine + ammonia

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

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].

   

L-Serine

(2S)-2-amino-3-hydroxypropanoic acid

C3H7NO3 (105.0426)


Serine (Ser) or L-serine 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-serine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Serine is found in all organisms ranging from bacteria to plants to animals. It is classified as a polar, uncharged (at physiological pH), aliphatic amino acid. In humans, serine is a nonessential amino acid that can be easily derived from glycine. 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. Like all the amino acid building blocks of protein and peptides, serine can become essential under certain conditions, and is thus important in maintaining health and preventing disease. L-Serine may be derived from four possible sources: dietary intake; biosynthesis from the glycolytic intermediate 3-phosphoglycerate; from glycine; and by protein and phospholipid degradation. Little data is available on the relative contributions of each of these four sources of l-serine to serine homoeostasis. It is very likely that the predominant source of l-serine will be very different in different tissues and during different stages of human development. In the biosynthetic pathway, the glycolytic intermediate 3-phosphoglycerate is converted into phosphohydroxypyruvate, in a reaction catalyzed by 3-phosphoglycerate dehydrogenase (3- PGDH; EC 1.1.1.95). Phosphohydroxypyruvate is metabolized to phosphoserine by phosphohydroxypyruvate aminotransferase (EC 2.6.1.52) and, finally, phosphoserine is converted into l-serine by phosphoserine phosphatase (PSP; EC 3.1.3.3). In liver tissue, the serine biosynthetic pathway is regulated in response to dietary and hormonal changes. Of the three synthetic enzymes, the properties of 3-PGDH and PSP are the best documented. Hormonal factors such as glucagon and corticosteroids also influence 3-PGDH and PSP activities in interactions dependent upon the diet. L-serine is the predominant source of one-carbon groups for the de novo synthesis of purine nucleotides and deoxythymidine monophosphate. It has long been recognized that, in cell cultures, L-serine is a conditional essential amino acid, because it cannot be synthesized in sufficient quantities to meet the cellular demands for its utilization. In recent years, L-serine and the products of its metabolism have been recognized not only to be essential for cell proliferation, but also to be necessary for specific functions in the central nervous system. The findings of altered levels of serine and glycine in patients with psychiatric disorders and the severe neurological abnormalities in patients with defects of L-serine synthesis underscore the importance of L-serine in brain development and function. (PMID 12534373). [Spectral] L-Serine (exact mass = 105.04259) and D-2-Aminobutyrate (exact mass = 103.06333) and 4-Aminobutanoate (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. Dietary supplement. L-Serine is found in many foods, some of which are cold cut, mammee apple, coho salmon, and carrot. L-Serine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=56-45-1 (retrieved 2024-07-01) (CAS RN: 56-45-1). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Serine ((-)-Serine; (S)-Serine), one of the so-called non-essential amino acids, plays a central role in cellular proliferation. L-Serine ((-)-Serine; (S)-Serine), one of the so-called non-essential amino acids, plays a central role in cellular proliferation.

   

L-Cysteine

(2R)-2-amino-3-sulfanylpropanoic acid

C3H7NO2S (121.0197)


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].

   

Alpha-ketobutyrate

2-oxobutanoic acid

C4H6O3 (102.0317)


3-methyl pyruvic acid, also known as alpha-ketobutyric acid or 2-oxobutyric acid, belongs to short-chain keto acids and derivatives class of compounds. Those are keto acids with an alkyl chain the contains less than 6 carbon atoms. Thus, 3-methyl pyruvic acid is considered to be a fatty acid lipid molecule. 3-methyl pyruvic acid is soluble (in water) and a weakly acidic compound (based on its pKa). 3-methyl pyruvic acid can be found in a number of food items such as pepper (c. baccatum), triticale, european plum, and black walnut, which makes 3-methyl pyruvic acid a potential biomarker for the consumption of these food products. 3-methyl pyruvic acid can be found primarily in blood, cerebrospinal fluid (CSF), saliva, and urine. 3-methyl pyruvic acid exists in all living species, ranging from bacteria to humans. In humans, 3-methyl pyruvic acid is involved in several metabolic pathways, some of which include methionine metabolism, homocysteine degradation, threonine and 2-oxobutanoate degradation, and propanoate metabolism. 3-methyl pyruvic acid is also involved in several metabolic disorders, some of which include dimethylglycine dehydrogenase deficiency, methylenetetrahydrofolate reductase deficiency (MTHFRD), s-adenosylhomocysteine (SAH) hydrolase deficiency, and hyperglycinemia, non-ketotic. 2-Ketobutyric acid, also known as alpha-ketobutyrate or 2-oxobutyrate, belongs to the class of organic compounds known as short-chain keto acids and derivatives. These are keto acids with an alkyl chain the contains less than 6 carbon atoms. 2-Ketobutyric acid is a substance that is involved in the metabolism of many amino acids (glycine, methionine, valine, leucine, serine, threonine, isoleucine) as well as propanoate metabolism and C-5 branched dibasic acid metabolism. It is also one of the degradation products of threonine. It can be converted into propionyl-CoA (and subsequently methylmalonyl CoA, which can be converted into succinyl CoA, a citric acid cycle intermediate), and thus enter the citric acid cycle. More specifically, 2-ketobutyric acid is a product of the lysis of cystathionine. 2-Oxobutanoic acid is a product in the enzymatic cleavage of cystathionine.

   

Pyruvate

alpha-Ketopropanoic acid

C3H4O3 (88.016)


Pyruvic acid, also known as 2-oxopropanoic acid or alpha-ketopropionic acid, belongs to alpha-keto acids and derivatives class of compounds. Those are organic compounds containing an aldehyde substituted with a keto group on the adjacent carbon. Thus, pyruvic acid is considered to be a fatty acid lipid molecule. Pyruvic acid is soluble (in water) and a moderately acidic compound (based on its pKa). Pyruvic acid can be synthesized from propionic acid. Pyruvic acid is also a parent compound for other transformation products, including but not limited to, 4-hydroxy-3-iodophenylpyruvate, 3-acylpyruvic acid, and methyl pyruvate. Pyruvic acid can be found in a number of food items such as kumquat, groundcherry, coconut, and prunus (cherry, plum), which makes pyruvic acid a potential biomarker for the consumption of these food products. Pyruvic acid can be found primarily in most biofluids, including sweat, blood, urine, and feces, as well as throughout most human tissues. Pyruvic acid exists in all living species, ranging from bacteria to humans. In humans, pyruvic acid is involved in several metabolic pathways, some of which include glycogenosis, type IB, glycolysis, urea cycle, and gluconeogenesis. Pyruvic acid is also involved in several metabolic disorders, some of which include non ketotic hyperglycinemia, pyruvate dehydrogenase complex deficiency, fructose-1,6-diphosphatase deficiency, and 4-hydroxybutyric aciduria/succinic semialdehyde dehydrogenase deficiency. Moreover, pyruvic acid is found to be associated with anoxia, schizophrenia, fumarase deficiency, and meningitis. Pyruvic acid is a non-carcinogenic (not listed by IARC) potentially toxic compound. Pyruvic acid is a drug which is used for nutritional supplementation, also for treating dietary shortage or imbalanc. Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through a reaction with acetyl-CoA. It can also be used to construct the amino acid alanine and can be converted into ethanol or lactic acid via fermentation . Those taking large doses of supplemental pyruvate—usually greater than 5 grams daily—have reported gastrointestinal symptoms, including abdominal discomfort and bloating, gas and diarrhea. One child receiving pyruvate intravenously for restrictive cardiomyopathy died (DrugBank). Pyruvate serves as a biological fuel by being converted to acetyl coenzyme A, which enters the tricarboxylic acid or Krebs cycle where it is metabolized to produce ATP aerobically. Energy can also be obtained anaerobically from pyruvate via its conversion to lactate. Pyruvate injections or perfusions increase contractile function of hearts when metabolizing glucose or fatty acids. This inotropic effect is striking in hearts stunned by ischemia/reperfusion. The inotropic effect of pyruvate requires intracoronary infusion. Among possible mechanisms for this effect are increased generation of ATP and an increase in ATP phosphorylation potential. Another is activation of pyruvate dehydrogenase, promoting its own oxidation by inhibiting pyruvate dehydrogenase kinase. Pyruvate dehydrogenase is inactivated in ischemia myocardium. Yet another is reduction of cytosolic inorganic phosphate concentration. Pyruvate, as an antioxidant, is known to scavenge such reactive oxygen species as hydrogen peroxide and lipid peroxides. Indirectly, supraphysiological levels of pyruvate may increase cellular reduced glutathione (T3DB). Pyruvic acid or pyruvate is a simple alpha-keto acid. It is a three-carbon molecule containing a carboxylic acid group and a ketone functional group. Pyruvate is the simplest alpha-keto acid and according to official nomenclature by IUPAC, it is called alpha-keto propanoic acid. Like other keto acids, pyruvic acid can tautomerize from its ketone form to its enol form, containing a double bond and an alcohol. Pyruvate is found in all living organisms ranging from bacteria to plants to humans. It is intermediate compound in the metabolism of carbohydrates, proteins, and fats. Pyruvate is a key intermediate in several metabolic pathways throughout the cell. In particular, pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through a reaction with acetyl-CoA. Pyruvic acid supplies energy to cells through the citric acid cycle (TCA or Krebs cycle) when oxygen is present (aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking (lactic acid). In glycolysis, phosphoenolpyruvate (PEP) is converted to pyruvate by pyruvate kinase. This reaction is strongly exergonic and irreversible. In gluconeogenesis, it takes two enzymes, pyruvate carboxylase and PEP carboxykinase, to catalyze the reverse transformation of pyruvate to PEP. Pyruvic acid is also a metabolite of Corynebacterium (PMID: 27872963). Pyruvic acid. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=127-17-3 (retrieved 2024-07-01) (CAS RN: 127-17-3). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Pyruvic acid is an intermediate metabolite in the metabolism of carbohydrates, proteins, and fats. Pyruvic acid is an intermediate metabolite in the metabolism of carbohydrates, proteins, and fats.

   

Acetic acid

Acetic acid

C2H4O2 (60.0211)


Acetic acid is a two-carbon, straight-chain fatty acid. It is the smallest short-chain fatty acid (SCFA) and one of the simplest carboxylic acids. is an acidic, colourless liquid and is the main component in vinegar. Acetic acid has a sour taste and pungent smell. It is an important chemical reagent and industrial chemical that is used in the production of plastic soft drink bottles, photographic film; and polyvinyl acetate for wood glue, as well as many synthetic fibres and fabrics. In households diluted acetic acid is often used as a cleaning agent. In the food industry acetic acid is used as an acidity regulator. Acetic acid is found in all organisms, from bacteria to plants to humans. The acetyl group, derived from acetic acid, is fundamental to the biochemistry of virtually all forms of life. When bound to coenzyme A (to form acetylCoA) it is central to the metabolism of carbohydrates and fats. However, the concentration of free acetic acid in cells is kept at a low level to avoid disrupting the control of the pH of the cell contents. Acetic acid is produced and excreted in large amounts by certain acetic acid bacteria, notably the Acetobacter genus and Clostridium acetobutylicum. These bacteria are found universally in foodstuffs, water, and soil. Due to their widespread presence on fruit, acetic acid is produced naturally as fruits and many other sugar-rich foods spoil. Several species of anaerobic bacteria, including members of the genus Clostridium and Acetobacterium can convert sugars to acetic acid directly. However, Clostridium bacteria are less acid-tolerant than Acetobacter. Even the most acid-tolerant Clostridium strains can produce acetic acid in concentrations of only a few per cent, compared to Acetobacter strains that can produce acetic acid in concentrations up to 20\\%. Acetic acid is also a component of the vaginal lubrication of humans and other primates, where it appears to serve as a mild antibacterial agent. Acetic acid can be found in other biofluids such as urine at low concentrations. Urinary acetic acid is produced by bacteria such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus (PMID: 22292465). Acetic acid concentrations greater than 30 uM/mM creatinine in the urine can indicate a urinary tract infection, which typically suggests the presence of E. coli or Klebshiella pneumonia in the urinary tract. (PMID: 24909875) Acetic acid is also produced by other bacteria such as Akkermansia, Bacteroidetes, Bifidobacterium, Prevotella and Ruminococcus (PMID: 20444704; PMID: 22292465). G - Genito urinary system and sex hormones > G01 - Gynecological antiinfectives and antiseptics > G01A - Antiinfectives and antiseptics, excl. combinations with corticosteroids > G01AD - Organic acids S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives D019995 - Laboratory Chemicals > D007202 - Indicators and Reagents D000890 - Anti-Infective Agents > D000900 - Anti-Bacterial Agents It is used for smoking meats and fish C254 - Anti-Infective Agent KEIO_ID A029

   

O-acetylhomoserine

O-Acetyl-L-homoserine hydrochloride

C6H11NO4 (161.0688)


Acetylhomoserine is found in pulses. Acetylhomoserine is found in Pisum sativum (peas) Acquisition and generation of the data is financially supported in part by CREST/JST. Found in green tissues of pea (Pisum sativum)

   

Water

oxidane

H2O (18.0106)


Water is a chemical substance that is essential to all known forms of life. It appears colorless to the naked eye in small quantities, though it is actually slightly blue in color. It covers 71\\% of Earths surface. Current estimates suggest that there are 1.4 billion cubic kilometers (330 million m3) of it available on Earth, and it exists in many forms. It appears mostly in the oceans (saltwater) and polar ice caps, but it is also present as clouds, rain water, rivers, freshwater aquifers, lakes, and sea ice. Water in these bodies perpetually moves through a cycle of evaporation, precipitation, and runoff to the sea. Clean water is essential to human life. In many parts of the world, it is in short supply. From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions) in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes. Water is also central to photosynthesis and respiration. Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process (cellular respiration). Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H+, that is, a proton) donor, can be neutralized by a base, a proton acceptor such as hydroxide ion (OH-) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7. Stomach acid (HCl) is useful to digestion. However, its corrosive effect on the esophagus during reflux can temporarily be neutralized by ingestion of a base such as aluminum hydroxide to produce the neutral molecules water and the salt aluminum chloride. Human biochemistry that involves enzymes usually performs optimally around a biologically neutral pH of 7.4. (Wikipedia). Water, also known as purified water or dihydrogen oxide, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Water can be found in a number of food items such as caraway, oxheart cabbage, alaska wild rhubarb, and japanese walnut, which makes water a potential biomarker for the consumption of these food products. Water can be found primarily in most biofluids, including ascites Fluid, blood, cerebrospinal fluid (CSF), and lymph, as well as throughout all human tissues. Water exists in all living species, ranging from bacteria to humans. In humans, water is involved in several metabolic pathways, some of which include cardiolipin biosynthesis CL(20:4(5Z,8Z,11Z,14Z)/18:0/20:4(5Z,8Z,11Z,14Z)/18:2(9Z,12Z)), cardiolipin biosynthesis cl(i-13:0/i-15:0/i-20:0/i-24:0), cardiolipin biosynthesis CL(18:0/18:0/20:4(5Z,8Z,11Z,14Z)/22:5(7Z,10Z,13Z,16Z,19Z)), and cardiolipin biosynthesis cl(a-13:0/i-18:0/i-13:0/i-19:0). Water is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis tg(i-21:0/i-13:0/21:0), de novo triacylglycerol biosynthesis tg(22:0/20:0/i-20:0), de novo triacylglycerol biosynthesis tg(a-21:0/i-20:0/i-14:0), and de novo triacylglycerol biosynthesis tg(i-21:0/a-17:0/i-12:0). Water is a drug which is used for diluting or dissolving drugs for intravenous, intramuscular or subcutaneous injection, according to instructions of the manufacturer of the drug to be administered [fda label]. Water plays an important role in the world economy. Approximately 70\\% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving .

   

ammonia

N-acetyl-α-D-glucosamine 1-phosphate

H3N (17.0265)


An azane that consists of a single nitrogen atom covelently bonded to three hydrogen atoms. Ammonia, also known as nh3 or ammonia solution, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Ammonia can be found in a number of food items such as rose hip, yardlong bean, cereals and cereal products, and ceylon cinnamon, which makes ammonia a potential biomarker for the consumption of these food products. Ammonia can be found primarily in blood, cellular cytoplasm, cerebrospinal fluid (CSF), and urine, as well as throughout all human tissues. Ammonia exists in all eukaryotes, ranging from yeast to humans. In humans, ammonia is involved in several metabolic pathways, some of which include glucose-alanine cycle, phenylalanine and tyrosine metabolism, homocysteine degradation, and d-arginine and d-ornithine metabolism. Ammonia is also involved in several metabolic disorders, some of which include ureidopropionase deficiency, hyperornithinemia-hyperammonemia-homocitrullinuria [hhh-syndrome], non ketotic hyperglycinemia, and beta-mercaptolactate-cysteine disulfiduria. Moreover, ammonia is found to be associated with 3-Hydroxy-3-methylglutaryl-CoA lyase deficiency, 3-Methyl-crotonyl-glycinuria, citrullinemia type I, and short bowel syndrome. Ammonia is a non-carcinogenic (not listed by IARC) potentially toxic compound. Ammonia or azane is a compound of nitrogen and hydrogen with the formula NH3. The simplest pnictogen hydride, ammonia is a colourless gas with a characteristic pungent smell. It is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products . Acute Exposure: EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration. (z)-n-coumaroyl-5-hydroxyanthranilic acid is a member of the class of compounds known as avenanthramides. Avenanthramides are a group of phenolic alkaloids consisting of conjugate of three phenylpropanoids (ferulic, caffeic, or p-coumaric acid) and anthranilic acid (z)-n-coumaroyl-5-hydroxyanthranilic acid is practically insoluble (in water) and a weakly acidic compound (based on its pKa). (z)-n-coumaroyl-5-hydroxyanthranilic acid can be found in cereals and cereal products and oat, which makes (z)-n-coumaroyl-5-hydroxyanthranilic acid a potential biomarker for the consumption of these food products.