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Lactic acid is an organic acid. It is a chiral molecule, consisting of two optical isomers, L-lactic acid and D-lactic acid, with the L-isomer being the most common in living organisms. Lactic acid plays a role in several biochemical processes and is produced in the muscles during intense activity. In animals, L-lactate is constantly produced from pyruvate via the enzyme lactate dehydrogenase (LDH) in a process of fermentation during normal metabolism and exercise. It does not increase in concentration until the rate of lactate production exceeds the rate of lactate removal. This is governed by a number of factors, including monocarboxylate transporters, lactate concentration, the isoform of LDH, and oxidative capacity of tissues. The concentration of blood lactate is usually 1-2 mmol/L at rest, but can rise to over 20 mmol/L during intense exertion. There are some indications that lactate, and not glucose, is preferentially metabolized by neurons in the brain of several mammalian species, including mice, rats, and humans. Glial cells, using the lactate shuttle, are responsible for transforming glucose into lactate, and for providing lactate to the neurons. Lactate measurement in critically ill patients has been traditionally used to stratify patients with poor outcomes. However, plasma lactate levels are the result of a finely tuned interplay of factors that affect the balance between its production and its clearance. When the oxygen supply does not match its consumption, organisms adapt in many different ways, up to the point when energy failure occurs. Lactate, being part of the adaptive response, may then be used to assess the severity of the supply/demand imbalance. In such a scenario, the time to intervention becomes relevant: early and effective treatment may allow tissues and cells to revert to a normal state, as long as the oxygen machinery (i.e. mitochondria) is intact. Conversely, once the mitochondria are deranged, energy failure occurs even in the presence of normoxia. The lactate increase in critically ill patients may, therefore, be viewed as an early marker of a potentially reversible state (PMID: 16356243). When present in sufficiently high levels, lactic acid can act as an oncometabolite, an immunosuppressant, an acidogen, and a metabotoxin. An oncometabolite is a compound that promotes tumor growth and survival. An immunosuppressant reduces or arrests the activity of the immune system. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of lactic acid are associated with at least a dozen inborn errors of metabolism, including 2-methyl-3-hydroxybutyryl CoA dehydrogenase deficiency, biotinidase deficiency, fructose-1,6-diphosphatase deficiency, glycogen storage disease type 1A (GSD1A) or Von Gierke disease, glycogenosis type IB, glycogenosis type IC, glycogenosis type VI, Hers disease, lactic acidemia, Leigh syndrome, methylmalonate semialdehyde dehydrogenase deficiency, pyruvate decarboxylase E1 component deficiency, pyruvate dehydrogenase complex deficiency, pyruvate dehydrogenase deficiency, and short chain acyl CoA dehydrogenase deficiency (SCAD deficiency). Locally high concentrations of lactic acid or lactate are found near many tumors due to the upregulation of lactate dehydrogenase (PMID: 15279558). Lactic acid produced by tumors through aerobic glycolysis acts as an immunosuppressant and tumor promoter (PMID: 23729358). Indeed, lactic acid has been found to be a key player or regulator in the development and malignant progression of a variety of cancers (PMID: 22084445). A number of studies have demonstrated that malignant transformation is associated with an increase in aerobic cellular lactate excretion. Lactate concentrations in various carcinomas (e.g. uterine cervix, head and neck, colorectal region) at first diagnosis of the disease, can be relatively low or extremely high (up to 40 µmol/g) in different individual tumors or within the same lesion (PMID: 15279558). High molar concentrations of lactate are correlated with a high incidence of distant metastasis. Low lactate tumors (< median of approximately 8 µmol/g) are associated with both an overall longer and disease-free survival compared to high lactate lesions (lactate > approximately 8 µmol/g). Lactate-induced secretion of hyaluronan by tumor-associated fibroblasts creates a milieu favourable for cell migration and metastases (PMID: 22084445). An acidic environment (pH 6-6.5), which is common in many tumors, allows tumor cells to evade the immune response, and therefore allows them to grow unchecked. Locally high concentrations of lactic acid are known to markedly impede the function of normal immune cells and will lead to a loss of T-cell function of human tumor-infiltrating lymphocytes (PMID: 22084445). Lactic acid is also an organic acid and acts as a general acidogen. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart abnormalities, kidney abnormalities, liver damage, seizures, coma, and possibly death. These are also the characteristic symptoms of the untreated IEMs mentioned above. Many affected children with organic acidemias experience intellectual disability or delayed development. Lactic acid is also a microbial metabolite, urinary lactic acid is produced by Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus (PMID: 22292465), Bacillus, Corynebacterium, Rhizopus and Saccharomyces cerevisiae (PMID: 26360870).

Lactic acid is an organic acid. It is a chiral molecule, consisting of two optical isomers, L-lactic acid and D-lactic acid, with the L-isomer being the most common in living organisms. Lactic acid plays a role in several biochemical processes and is produced in the muscles during intense activity. D-Lactic acid is the end product of the enzyme glyoxalase II (or hydroxyacyl-glutathione hydrolase) (EC 3.1.2.6), which converts the intermediate substrate S-lactoyl-glutathione to reduced glutathione and D-lactate (OMIM: 138790). Lactic acid is a microbial metabolite found in Aerococcus, Bacillus, Carnobacterium, Corynebacterium, Enterococcus, Escherichia, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Rhizopus, Saccharomyces, Streptococcus, Tetragenococcus, Vagococcus and Weissella (PMID:26287368; PMID:26360870).

3-Hydroxypropionic acid is a carboxylic acid. It is an intermediate in the breakdown of branched-chain amino acids and propionic acid from the gut. Typically it originates from propionyl-CoA and a defect in the enzyme propionyl carboxylase. This leads to a buildup in propionyl-CoA in the mitochondria.  Such a buildup can lead to a disruption of the esterified CoA:free CoA ratio and ultimately to mitochondrial toxicity. Detoxification of these metabolic end products occurs via the transfer of the propionyl moiety to carnitine-forming propionyl-carnitine, which is then transferred across the inner mitochondrial membrane. 3-Hydroxypropionic acid is then released as the free acid. As an industrial chemical, it is used in the production of various chemicals such as acrylates in industry. When present in sufficiently high levels, 3-hydroxypropionic acid can act as an acidogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of hydroxypropionic acid are associated with many inborn errors of metabolism including biotinidase deficiency, malonic aciduria, methylmalonate semialdehyde dehydrogenase deficiency, methylmalonic aciduria, methylmalonic aciduria due to cobalamin-related disorders, and propionic acidemia. Hydroxypropionic acid is an organic acid. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. Infants with acidosis have symptoms that include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart, liver, and kidney abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of the IEMs mentioned above. Many affected children with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. 3-Hydroxypropionic acid is also a microbial metabolite found in Escherichia, Klebsiella and Saccharomyces (PMID: 26360870).

A 2-hydroxy monocarboxylic acid that is propanoic acid in which one of the alpha-hydrogens is replaced by a hydroxy group." []

Dimethyl carbonate is used for cold sterilisation of beverages. Effective against typical beverage-spoiling microorganisms, like yeasts and fermentative bacteria Dimethyl carbonate, often abbreviated DMC, is a flammable clear liquid boiling at 90 °C. It has recently found use as a methylating reagent. Its main benefit over other methylating reagents such as iodomethane and dimethyl sulfate is its lesser toxicity and its biodegradability. Also, it is now prepared from catalytic oxidative carbonylation of methanol with carbon monoxide and oxygen, instead of from phosgene making its production non-toxic and environmentally friendly. This allows dimethyl carbonate to be considered a green reagent

Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colourless crystalline solid that is an intermediate compound in carbohydrate metabolism. The word "glyceraldehyde" comes from combining glycerine and aldehyde, as glyceraldehyde is merely glycerine with one hydroxide changed to an aldehyde. Glyceraldehyde is produced from the action of the enzyme glyceraldehyde dehydrogenase, which converts glycerol to glyceraldehyde using NADP as a cofactor. When present at sufficiently high levels, glyceraldehyde can be a cytotoxin and a mutagen. A cytotoxin is a compound that kills cells. A mutagen is a compound that causes mutations in DNA. Glyceraldehyde is a highly reactive compound that can modify and cross-link proteins. Glyceraldehyde-modified proteins appear to be cytotoxic, depress intracellular glutathione levels, and induce reactive oxygen species (ROS) production (PMID:14981296). Glyceraldehyde has been shown to cause chromosome damage to human cells in culture and is mutagenic in the Ames bacterial test.

Methoxyacetic acid belongs to the family of Carboxylic Acids. These are compounds containing a carboxylic acid group with the formula -C(=O)OH.

1,1-Dihydroxypropan-2-one is a natural product found in Homo sapiens, Catharanthus roseus, and other organisms with data available.

Dihydroxyacetone (also known as DHA) is a ketotriose compound. Its addition to blood preservation solutions results in better maintenance of 2,3-diphosphoglycerate levels during storage. It is readily phosphorylated to dihydroxyacetone phosphate by triokinase in erythrocytes. In combination with naphthoquinones, it acts as a sunscreening agent. Dihydroxyacetone is the simplest of all ketoses and, having no chiral centre, is the only one that has no optical activity. Dihydroxyacetone is a simple non-toxic sugar. It is often derived from plant sources such as sugar beets and sugar cane, by the fermentation of glycerin. Dihydroxyacetone is a white crystalline powder which is water soluble.

Oxalic acid is a strong dicarboxylic acid occurring in many plants and vegetables. It is produced in the body by metabolism of glyoxylic acid or ascorbic acid. It is not metabolized but excreted in the urine. It is used as an analytical reagent and general reducing agent (Pubchem). Oxalic acid (IUPAC name: ethanedioic acid, formula H2C2O4) is a dicarboxylic acid with structure (HOOC)-(COOH). Because of the joining of two carboxyl groups, this is one of the strongest organic acids. It is also a reducing agent. The anions of oxalic acid as well as its salts and esters are known as oxalates (Wikipedia). Bodily oxalic acid may also be synthesized via the metabolism of either glyoxylic acid or unused ascorbic acid (vitamin C), which is a serious health consideration for long term megadosers of vitamin C supplements. 80% of kidney stones are formed from calcium oxalate. Some Aspergillus species produce oxalic acid, which reacts with blood or tissue calcium to precipitate calcium oxalate. There is some preliminary evidence that the administration of probiotics can affect oxalic acid excretion rates (and presumably oxalic acid levels as well) (Wikipedia). Oxalic acid is found to be associated with fumarase deficiency and primary hyperoxaluria I, which are inborn errors of metabolism. Oxalic acid is a marker for yeast overgrowth from Aspergillus, Penicillum and/or Candida. Can also be elevated due to exposures from vitamin C or ethylene glycol poisoning. Oxalate is elevated in the urine of children with autism. (PMID: 21911305). Oxalic acid has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821).

The D-enantiomer of glyceraldehyde." []

The L-enantiomer of glyceraldehyde." []

Isobutyric acid is a carboxylic or short chain fatty acid with characteristic sweat-like smell. Small amount of isobutyrate is generated via microbial (gut) metabolism. Small amounts may also be found in certain foods or fermented beverages. There is anosmia (genetic inability to smell) for the odor of isobutyric acid with a frequency of about 2.5%. (OMIM 207000). Isobutyric acid is slightly soluble in water but much more soluble in ethanol, ether and organic solvents. Isobutyric acid can affect people if breathed in and may be absorbed through the skin. Contact can irritate and burn the skin and eyes. Breathing Isobutyric acid can irritate the nose, throat and lungs causing coughing, wheezing and/or shortness of breath.

Beta-alaninamide is an amino acid amide compound consisting of propionamide having a 3-amino substituent. It is a conjugate base of a beta-alaninium amide.

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 crohn's 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.

Formaldehyde is a highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717) -- Pubchem; The chemical compound formaldehyde (also known as methanal), is a gas with a pungent smell. It is the simplest aldehyde. Its chemical formula is H2CO. Formaldehyde was first synthesized by the Russian chemist Aleksandr Butlerov in 1859 but was conclusively identified by August Wilhelm van Hofmann in 1867. Although formaldehyde is a gas at room temperature, it is readily soluble in water, and it is most commonly sold as a 37% solution in water called by trade names such as formalin or formol. In water, formaldehyde polymerizes, and formalin actually contains very little formaldehyde in the form of H2CO monomer. Usually, these solutions contain a few percent methanol to limit the extent of polymerization. Formaldehyde exhibits most of the general chemical properties of the aldehydes, except that is generally more reactive than other aldehydes. Formaldehyde is a potent electrophile. It can participate in electrophilic aromatic substitution reactions with aromatic compounds and can undergo electrophilic addition reactions with alkenes. In the presence of basic catalysts, formaldehyde undergoes a Cannizaro reaction to produce formic acid and methanol. Because formaldehyde resins are used in many construction materials, including plywood, carpet, and spray-on insulating foams, and because these resins slowly give off formaldehyde over time, formaldehyde is one of the more common indoor air pollutants. At concentrations above 0.1 mg/kg in air, inhaled formaldehyde can irritate the eyes and mucous membranes, resulting in watery eyes, headache, a burning sensation in the throat, and difficulty breathing. -- Wikipedia.

A methyl ketone that is butan-2-one substituted by a hydroxy group at position 3." []

Transparent crystals or white crystalline solid with a pleasant odor resembling the odor of chloroform. Melts at 62 °C; boils at 115 °C without polymerization. The cyclic trimer of formaldehyde. 1,3,5-trioxane is a saturated organic heteromonocyclic parent that is cyclohexane in which the carbon atoms at positions 1, 3 and 5 are replaced by oxygen atoms. It is a trioxane and a saturated organic heteromonocyclic parent.

cis-2,3-Dimethylthiirane is a component of food flavours.

1-Deoxy-L-erythritol is a constituent of the fruit of Carum ajowan (ajowan).

Tetrahydrothiophene appears as a water-white liquid. About the same density as water and insoluble in water. Vapors heavier than air. Used as a solvent and to make other chemicals. Tetrahydrothiophene is a saturated organic heteromonocyclic parent and a member of tetrahydrothiophenes.

1-Hydroxy-2-butanone is found in coffee and coffee products. 1-Hydroxy-2-butanone is a constituent of coffee and various edible mushrooms. 1-Hydroxy-2-butanone is a flavouring ingredient

1-Propene, 1-(methylthio)-, (E)- belongs to the family of Thioethers. These are compounds containing the ester derivative of thiocarboxylic acid,with the general structure R-S-R' (R,R'=alkyl,aryl)

A triol that is butane carrying three hydroxy substituents at position 1, 2 and 4." []

(Z)-1-(Methylthio)-1-propene belongs to the class of organic compounds known as thioethers. These are compounds containing the ester derivative of thiocarboxylic acid,with the general structure R-S-R' (R,R'=alkyl,aryl).

Trihydroxybutane belongs to the class of organic compounds known as polyols. These are organic compounds containing more than one hydroxyl groups.