Classification Term: 170027
脂肪酸和共轭物 (ontology term: 02b6411c98fc65ae915798985b2e04f5)
found 18 associated metabolites at sub_class metabolite taxonomy ontology rank level.
Ancestor: 脂质和类脂分子
Child Taxonomies: There is no child term of current ontology term.
3-hydroxy-3-methylglutarate
3-Hydroxymethylglutaric acid is an "off-product" intermediate in the leucine degradation process. It is produced by defective or inefficient versions of 3-hydroxy-3-methylglutaryl-CoA lyase, an enzyme that normally catalyzes the conversion of 3-hydroxy-3-methylglutaryl-CoA to acetyl-CoA and acetoacetate. If this enzyme is defective, 3-hydroxy-3-methylglutaryl-CoA will accumulate in the mitochondria. Increased concentrations of 3-hydroxy-3-methylglutaryl-CoA can lead to a disruption of the esterified CoA:free CoA ratio and ultimately to mitochondrial toxicity. Detoxification of these CoA end products occurs via the transfer of the 3-hydroxymethylglutaryl moiety to carnitine, forming 3-hydroxymethylglutaric-carnitine, which is then transferred across the inner mitochondrial membrane where 3-hydroxymethylglutaric acid is released as the free acid. 3-Hydroxymethylglutaric acid has been found to accumulate in the urine of patients affected by 3-Hydroxy-3-methylglutaric aciduria, a rare inborn error of metabolism (OMIM: 246450). 3-Hydroxy-3-methylglutaric aciduria is caused by significantly reduced enzyme activity of the intramitochondrial 3-hydroxy-3-methylglutaryl-CoA lyase (EC 4.1.3.4), the enzyme that catalyzes the final step of leucine degradation. This enzyme also plays a key role in ketone body formation. The profile of urinary organic acids for individuals with 3-hydroxy-3-methylglutaric aciduria is different from that of the other identified defects of leucine degradation, such as maple syrup urine disease (OMIM: 248600), isovaleric acidemia (OMIM: 243500), and methylcrotonylglycinemia (OMIM: 210200). The urinary organic acid profile of 3-hydroxy-3-methylglutaric aciduria includes elevated concentrations of 3-hydroxy-3-isovaleric, 3-hydroxy-3-methylglutaric, 3-methylglutaconic, and 3-methylglutaric acids (PMID: 10916782, 9658458, 3063529). Clinical manifestations of 3-hydroxy-3-methylglutaric aciduria include hepatomegaly, lethargy, coma, and apnea. Biochemically, there is a characteristic absence of ketosis with hypoglycemia, acidosis, hypertransaminasemia, and variable hyperammonemia. Therefore, when present in sufficiently high concentrations, 3-hydroxymethylglutaric 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. As noted above, chronically high levels of 3-hydroxymethylglutaric acid are associated with the inborn error of metabolism 3-hydroxy-3-methylglutaryl-CoA lyase deficiency. 3-Hydroxymethylglutaric 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. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart, liver, and kidney abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of the untreated IEMs mentioned above. Many affected children with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. 3-hydroxymethylglutaric acid, also known as meglutol or dicrotalic acid, is a member of the class of compounds known as hydroxy fatty acids. Hydroxy fatty acids are fatty acids in which the chain bears a hydroxyl group. 3-hydroxymethylglutaric acid is soluble (in water) and a weakly acidic compound (based on its pKa). 3-hydroxymethylglutaric acid can be synthesized from glutaric acid. 3-hydroxymethylglutaric acid is also a parent compound for other transformation products, including but not limited to, viscumneoside VII, viscumneoside IV, and yanuthone D. 3-hydroxymethylglutaric acid can be found in flaxseed, which makes 3-hydroxymethylglutaric acid a potential biomarker for the consumption of this food product. 3-hydroxymethylglutaric acid can be found primarily in saliva and urine. 3-hydroxymethylglutaric acid is a non-carcinogenic (not listed by IARC) potentially toxic compound. Chronically high levels of 3-hydroxymethylglutaric acid are associated with the inborn error of metabolism: 3-Hydroxy-3-Methylglutaryl-CoA Lyase Deficiency (T3DB). Meglutol is an antilipidemic agent that lowers cholesterol, triglycerides, and serum beta-lipoproteins and phospholipids, and inhibits hydroxymethylglutaryl-CoA reductase activity, which is the rate-limiting enzyme in cholesterol biosynthesis. Meglutol is an antilipidemic agent that lowers cholesterol, triglycerides, and serum beta-lipoproteins and phospholipids, and inhibits hydroxymethylglutaryl-CoA reductase activity, which is the rate-limiting enzyme in cholesterol biosynthesis.
12,13-DiHOME
12,13-DHOME (CAS: 263399-35-5), also known as 12,13-dihydroxy-9-octadecenoic acid or 12,13-DiHOME, is the epoxide hydrolase metabolite of the leukotoxin 12,13-EpOME. 12,13-EpOME acts as a protoxin, with the corresponding epoxide hydrolase 12,13-DHOME specifically exerting toxicity. Both the EpOME and the DHOME are shown to have neutrophil chemotactic activity. 12,13-DHOME suppress the neutrophil respiratory burst by a mechanism distinct from that of respiratory burst inhibitors such as cyclosporin H or lipoxin A4, which inhibit multiple aspects of neutrophil activation. 12,13-DHOME is a derivative of the linoleic acid diol that has been reported to be toxic in human tissue preparations. 12,13-DHOME is a naturally occurring proliferator-activated receptor (PPAR) gamma2 ligand, which stimulates adipocytes and inhibits osteoblast differentiation (PMID: 17435320, 12021203, 12127265). 12,13-DHOME is the epoxide hydrolase metabolite of the leukotoxin12,13-EpOME. 12,13-EpOMEs act as a protoxin, with the corresponding epoxide hydrolase 12,13-DiHOME specifically exerting toxicity. Both the EpOME and the DiHOME are shown to have neutrophil chemotactic activity. 12,13-DiHOME suppress the neutrophil respiratory burst by a mechanism distinct from that of respiratory burst inhibitors such as cyclosporin H or lipoxin A4,which inhibit multiple aspects of neutrophil activation. 12,13-DHOME is a derivative of linoleic acid diol that have been reported to be toxic in humans tissue preparations. 12,13-DHOME is a naturally occurring proliferator-activated receptor (PPAR) gamma2 ligand, which stimulates adipocytes and inhibits osteoblast differentiation. (PMID: 17435320, 12021203, 12127265) [HMDB]
Citramalate
Citramalic acid, also known as 2-Methylmalic acid, is an analog of malic acid. The structure of citramalic acid is similar to the structure of malic acid except it has an extra CH3 group on position 2. It is also classified as a 2-hydroxydicarboxylic acid. Citramalic acid exists in two isomers, L-citramalic acid and D-citramalic acid. The L-isomer is more biologically relevant isomer. Citramalic acid is found in almost all living organisms from microbes to plants to humans although citramalate is primarily produced from bacteria. L-citramalic acid was first isolated from the peel of apples in 1954 (PMID: 13160011). It has also been isolated in wine and other ripening fruit (PMID: 13807713). Citramalic acid can inhibit the production of malic acid. Citramalic acid is also an important microbial metabolite and has been found to be a byproduct of Saccharomyces yeast species, as well as Propionibacterium acnes and Aspergillus niger (PMID: 31827810) (http://drweyrich.weyrich.com/labs/oat.html) (PMID: 7628083). Citramalic acid is a component of the C5-branched dibasic acid metabolism pathway. It can be broken down by the enzyme citramalate lyase, which converts citramalate to acetate and pyruvate. Citramalate synthase is an enzyme found in bacteria that synthesizes citramalic acid from acetyl-CoA, pyruvate and water. Citramalic acid may have a useful role in medical diagnoses. It has been found in the urine of two brothers with autistic features (PMID: 7628083). Citramalic acid can also be used as a urinary marker for gut dysbiosis (PMID: 31669633). Dysbiosis is a disorder of the bacterial flora of the human digestive tract. It is usually diagnosed clinically by direct detection of an abnormal pattern of the intestinal microbiota. Constituent of apple peel. (R)-2-Hydroxy-2-methylbutanedioic acid is found in pomes.
9,10-DiHOME
9,10-Dihydroxy-12-octadecenoic acid (CAS: 263399-34-4), also known as 9,10-DHOME, is a derivative of linoleic acid diol and has been reported to be toxic in humans tissue preparations. 9,10-DHOME is a naturally occurring proliferator-activated receptor (PPAR) gamma2 ligand, which stimulates adipocytes and inhibits osteoblast differentiation. 9,10-DHOME is the epoxide hydrolase metabolite of the leukotoxin 9,10-EpOME. 9,10-EpOME act as a protoxin, with the corresponding epoxide hydrolase metabolite 9,10-DHOME, specifically exerting toxicity. Both 9,10-EpOME and 9,10-DHOME are shown to have neutrophil chemotactic activity. 9,10-DHOME suppresses the neutrophil respiratory burst by a mechanism distinct from that of respiratory burst inhibitors such as cyclosporin H or lipoxin A4, which inhibit multiple aspects of neutrophil activation (PMID: 12021203, 12127265, 17435320). 9,10-DHOME is found in fruits and can be isolated from the seeds of Cucurbita pepo. 9,10-DHOME is a derivative of linoleic acid diol that have been reported to be toxic in humans tissue preparations. 9,10-DHOME is a naturally occurring proliferator-activated receptor (PPAR) gamma2 ligand, which stimulates adipocytes and inhibits osteoblast differentiation. 9,10-DHOME is the epoxide hydrolase metabolite of the leukotoxin 9,10--EpOME. 9,10-EpOMEs act as a protoxin, with the corresponding epoxide hydrolase 9,10-DiHOME specifically exerting toxicity. Both the 9,10-EpOME and the 9,10-DiHOME are shown to have neutrophil chemotactic activity. 9,10-DiHOME suppress the neutrophil respiratory burst by a mechanism distinct from that of respiratory burst inhibitors such as cyclosporin H or lipoxin A4,which inhibit multiple aspects of neutrophil activation. (PMID: 12021203, 12127265, 17435320) [HMDB]
Pantoate
Pantoic acid (along with beta-alanine) is used to synthesize pantothenic acid (vitamin B5) in most microorganisms and plants. Pantothenic acid is a structural component of coenzyme A (CoA) which is involved in essential biological processes such as the citric acid cycle (TCA cycle) and the synthesis of carbohydrates, proteins, and fat. Pantothenic acid is found widespread in foods but especially in egg yolk, offal, fish, whole-grains, legumes, mushrooms, avocados, broccoli, and royal jelly (from bees).
2-Hydroxy-2-methylbutyric acid
2-Hydroxy-2-methylbutyric acid, also known as (+/-)-2-hydroxy-2-methylbutanoate or 2-methyl-2-hydroxybutyric acid, belongs to the class of organic compounds known as hydroxy fatty acids. These are fatty acids in which the chain bears a hydroxyl group. 2-Hydroxy-2-methylbutyric acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. 2-Hydroxy-2-methylbutyric acid is an unusual metabolite found in the urine of patients with 2-hydroxyglutaric aciduria and maple syrup urine disease. 2-Hydroxy-2-methylbutyric acid is also a secondary metabolite found in human urine after exposure to the gasoline additive tert-amyl-Me-ether (TAME). (PMID 11504147, 10828258, 9260660, 11482739) [HMDB] (±)-2-Hydroxy-2-methylbutyric acid. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=3739-30-8 (retrieved 2024-07-02) (CAS RN: 3739-30-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). 2-Hydroxy-2-methylbutanoic acid, an unusual metabolite, is associated with 2-hydroxyglutaric aciduria and maple syrup urine disease.
3-Hydroxyvaleric acid
3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia. (PMID: 630060) [HMDB] 3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia. (PMID: 630060). 3-Hydroxyvaleric acid is a 5-carbon ketone body. 3-Hydroxyvaleric acid is anaplerotic, meaning it can refill the pool of TCA cycle intermediates.
Ethylmalonate
Ethylmalonic acid, also known as alpha-carboxybutyric acid or ethylmalonate, is a member of the class of compounds known as branched fatty acids. Branched fatty acids are fatty acids containing one or more branched chains. Ethylmalonic acid is soluble (in water) and a moderately acidic compound (based on its pKa). Ethylmalonic acid can be synthesized from malonic acid, and can be synthesized into (S)-ethylmalonyl-CoA and (R)-ethylmalonyl-CoA. Ethylmalonic acid can be found in blood, cerebrospinal fluid (CSF), and urine, as well as in human fibroblasts, prostate, and skeletal muscle tissues. Moreover, ethylmalonic acid is found to be associated with anorexia nervosa and malonyl-CoA decarboxylase deficiency. Ethylmalonic acid is a non-carcinogenic (not listed by IARC) potentially toxic compound. Chronically high levels of ethylmalonic acid are associated with at least two inborn errors of metabolism, including short-chain acyl-CoA dehydrogenase deficiency (SCAD deficiency) and ethylmalonic encephalopathy. Ethylmalonic acid is identified in the urine of patients with short-chain acyl-CoA dehydrogenase deficiency, which is a fatty acid metabolism disorder. When present at sufficiently high levels, ethylmalonic 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. Ethylmalonic 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. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart abnormalities, kidney abnormalities, liver damage, seizures, coma, and possibly death. These are also the characteristic symptoms of the untreated IEMs mentioned above. Many affected children with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. Ethylmalonic acid is identified in the urine of patients with short-chain acyl-coenzyme A dehydrogenase deficiency, which is a fatty acid metabolism disorder. [HMDB] Ethylmalonic acid is non-carcinogenic potentially toxic and associated with anorexia nervosa and malonyl-CoA decarboxylase deficiency.
Deoxycarnitine
4-Trimethylammoniobutanoic acid, also known as gamma-butyrobetaine (GBB) or 3-dehydroxycarnitine, is a highly water-soluble derivative of gamma-aminobutyric acid (GABA). It is also a precursor of L-carnitine. It is a substrate of gamma butyrobetaine hydroxylase/dioxygenase (also known as BBOX) which catalyzes the formation of L-carnitine from gamma-butyrobetaine, the last step in the L-carnitine biosynthesis pathway. Carnitine is essential for the transport of activated fatty acids across the mitochondrial membrane during mitochondrial beta-oxidation. Numerous disorders have been described that lead to disturbances in energy production and in intermediary metabolism which are characterized by the production and excretion of unusual acylcarnitines. A mutation in the gene coding for carnitine-acylcarnitine translocase, or the OCTN2 transporter aetiologically, causes a carnitine deficiency that results in poor intestinal absorption of dietary L-carnitine, impaired reabsorption by the kidney, and increased urinary loss. Determination of the qualitative pattern of acylcarnitines can be of diagnostic and therapeutic importance. The betaine structure of carnitine requires special analytical procedures for recording. The ionic nature of L-carnitine causes a high water solubility which decreases with increasing chain length of the ester group in the acylcarnitines. Therefore, the distribution of L-carnitine and acylcarnitines in various organs is defined by their function and their physicochemical properties as well. High-performance liquid chromatography (HPLC) permits screening for free and total carnitine, as well as complete quantitative acylcarnitine determination, including the long-chain acylcarnitine profile (PMID: 17508264, Monatshefte fuer Chemie (2005), 136(8), 1279-1291., Int J Mass Spectrom. 1999;188:39-52.). 3-Dehydroxycarnitine is an acylcarnitine. Numerous disorders have been described that lead to disturbances in energy production and in intermediary metabolism in the organism which are characterized by the production and excretion of unusual acylcarnitines. A mutation in the gene coding for carnitine-acylcarnitine translocase or the OCTN2 transporter aetiologically causes a carnitine deficiency that results in poor intestinal absorption of dietary L-carnitine, its impaired reabsorption by the kidney and, consequently, in increased urinary loss of L-carnitine. Determination of the qualitative pattern of acylcarnitines can be of diagnostic and therapeutic importance. The betaine structure of carnitine requires special analytical procedures for recording. The ionic nature of L-carnitine causes a high water solubility which decreases with increasing chain length of the ester group in the acylcarnitines. Therefore, the distribution of L-carnitine and acylcarnitines in various organs is defined by their function and their physico-chemical properties as well. High performance liquid chromatography (HPLC) permits screening for free and total carnitine, as well as complete quantitative acylcarnitine determination, including the long-chain acylcarnitine profile. (PMID: 17508264, Monatshefte fuer Chemie (2005), 136(8), 1279-1291., Int J Mass Spectrom. 1999;188:39-52.) [HMDB] COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Nicotinamide adenine dinucleotide phosphate
C21H28N7O17P3 (743.0754508000001)
Nicotinamide adenine dinucleotide phosphate (NADP) is a coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled with a pyrophosphate linkage to 5-phosphate adenosine 2,5-bisphosphate. NADP serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage (Dorland, 27th ed). This extra phosphate is added by the enzyme NAD+ kinase and removed via NADP+ phosphatase. NADP is also known as TPN (triphosphopyridine nucleotide) and it is an important cofactor used in anabolic reactions in all forms of cellular life. Examples include the Calvin cycle, cholesterol synthesis, fatty acid elongation, and nucleic acid synthesis (Wikipedia). NADP, a nicotinamide adenine dinucleotide, is a redox cofactor. NADP is a key cofactor for electron transfer in the metabolism, being alternately oxidized (NADP+) and reduced (NADPH). NADPH is the universal electron donor in cellular reductive biosyntheses and detoxification processes, and also plays a key role in oxidative defense system[1][2][3]. NADP, a nicotinamide adenine dinucleotide, is a redox cofactor. NADP is a key cofactor for electron transfer in the metabolism, being alternately oxidized (NADP+) and reduced (NADPH)[1][2].
9Z-Eicosenoic acid
Cis-gadoleic acid, also known as (Z)-eicos-9-enoic acid or 9c-eicosensaeure, is a member of the class of compounds known as long-chain fatty acids. Long-chain fatty acids are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. Thus, cis-gadoleic acid is considered to be a fatty acid lipid molecule. Cis-gadoleic acid is practically insoluble (in water) and a weakly acidic compound (based on its pKa). Cis-gadoleic acid can be found in a number of food items such as breakfast cereal, allium (onion), carrot, and sugar substitute, which makes cis-gadoleic acid a potential biomarker for the consumption of these food products. Cis-gadoleic acid can be found primarily in blood and feces. 9Z-Eicosenoic acid, also known as gadoleic acid, is a member of the class of compounds known as long-chain fatty acids. Long-chain fatty acids are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. 9Z-Eicosenoic acid is practically insoluble (in water) and a weakly acidic compound (based on its pKa). 9Z-Eicosenoic acid can be found in a number of food items such as lemon, sugar, garlic, and mung bean, which makes 9Z-eicosenoic acid a potential biomarker for the consumption of these food products. 9Z-Eicosenoic acid can be found in feces, blood, and urine. Gondoic acid (cis-11-Eicosenoic acid), a monounsaturated long-chain fatty acid, is contained in a variety of plant oils and nuts[1]. Gondoic acid (cis-11-Eicosenoic acid), a monounsaturated long-chain fatty acid, is contained in a variety of plant oils and nuts[1].
Hexadecadienoate (16:2n6)
7Z,10Z-Hexadecadienoic acid is a conjugated dienoic fatty acid metabolite of conjugated linoleic acid (CLA). CLAs are a naturally occurring group of positional and geometric isomers of linoleic acid, with potential beneficial effects on atherosclerosis, carcinogenesis or obesity in human. Although the molecular mechanisms are largely unknown, it has been proposed that the anti-atherogenic actions comprise reduction of membrane-bound arachidonic acid and peroxisome proliferator-activated receptor (PPAR)-γ-dependent inhibition of Nuclear Factor kappa B (NF-κB) activation and subsequently reduced prostanoid release. (PMID 16275160).
Arachidonic acid
A long-chain fatty acid that is a C20, polyunsaturated fatty acid having four (Z)-double bonds at positions 5, 8, 11 and 14. COVID info from WikiPathways Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS Arachidonic acid is an essential fatty acid and a major constituent of biomembranes. Arachidonic acid is an essential fatty acid and a major constituent of biomembranes.
2-Hydroxy-2-methylbutyric acid
A branched-chain fatty acid that is 2-methylbutyric acid substituted at C-2 by a hydroxy group. 2-Hydroxy-2-methylbutanoic acid, an unusual metabolite, is associated with 2-hydroxyglutaric aciduria and maple syrup urine disease.
Caproate (6:0)
A C6, straight-chain saturated fatty acid. Caproic acid, also known as hexanoic acid, is the carboxylic acid derived from hexane with the chemical formula CH3(CH2)4COOH. It is a colorless oily liquid with an odor that is fatty, cheesy, waxy, and like that of goats[1] or other barnyard animals. It is a fatty acid found naturally in various animal fats and oils, and is one of the chemicals that gives the decomposing fleshy seed coat of the ginkgo its characteristic unpleasant odor.[3] It is also one of the components of vanilla and cheese. The primary use of caproic acid is in the manufacture of its esters for use as artificial flavors, and in the manufacture of hexyl derivatives, such as hexylphenols.[1] Salts and esters of caproic acid are known as caproates or hexanoates. Several progestin medications are caproate esters, such as hydroxyprogesterone caproate and gestonorone caproate. Two other acids are named after goats: caprylic acid (C8) and capric acid (C10). Along with caproic acid, they account for 15\% of the fat in goat's milk. Caproic, caprylic, and capric acids (capric is a crystal- or wax-like substance, whereas the other two are mobile liquids) are not only used for the formation of esters, but also commonly used "neat" in: butter, milk, cream, strawberry, bread, beer, nut, and other flavors. Hexanoic acid. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=142-62-1 (retrieved 2024-07-16) (CAS RN: 142-62-1). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
11-Aminoundecanoic acid
11-Aminoundecanoic acid is an organic compound with the formula H2N(CH2)10CO2H. This white solid is classified as an amine and a fatty acid. 11-Aminoundecanoic acid is a precursor to Nylon-11.[1] As practiced by Arkema, 11-aminoundecanoic acid is prepared industrially from undecylenic acid, which is derived from castor oil.[2] The synthesis proceeds in four separate reactions: 1. Transesterification of castor oil to methyl ricinoleate: Crude castor oil consists of about 80\% triglycerides, from the ricinoleic acid, itself representing about 90\% of the oil.[3] It is quantitatively transesterified with methanol to methyl ricinoleate (the methyl ester of ricinoleic acid) in the presence of the basic sodium methoxide at 80 °C within 1 h reaction time in a stirred reactor. At the end of the reaction, the resulting glycerol separates and the liquid methyl ester is washed with water to remove residual glycerol. 2. Pyrolysis of methylricinoleate to heptanal and methyl undecenoate: Methylricinoleate is evaporated at 250 °C, mixed with hot steam (600 °C) in a 1:1 ratio and decomposed in a cracking furnace at 400 - 575 °C at a retention time of about 10 seconds into its cleavage products heptanal and methyl undecenoate. The cleavage of the aliphatic chain occurs in this variant of the steam cracking selectively between the hydroxymethylene and the allyl-methylene group. Besides heptanal and methyl undecenoate, a mixture of methyl esters of saturated and unsaturated C18-carboxylic acids is obtained. This mixture is known under the trade name Esterol and is used as a lubricant additive. 3. Hydrolysis of methyl undecenoate to 10-undecenoic acid The hydrolysis of the methyl ester with sodium hydroxide proceeds at 25 °C within 30 min with quantitative yield. After acidification with hydrochloric acid, solid 10-undecenoic acid (undecylenic acid) is obtained. 4. Hydrobromination of 10-undecenoic acid to 11-bromoundecanoic acid The undecenoic acid is dissolved in toluene and, in the presence of the radical initiator benzoyl peroxide (BPO), gaseous hydrogen bromide is added, in contrary to the Markovnikov rule ("anti-Markovnikov"). When cooled to 0 °C, the fast and highly exothermic reaction produces 11-bromoundecanoic acid in 95\% yield - the Markovnikov product 10-bromoundecanoic acid is produced in small quantities as a by-product. Toluene and unreacted hydrogen bromide are extracted under reduced pressure and reused. 5. Bromine exchange of 11-bromoundecanoic acid to 11-aminoundecanoic acid 11-Bromodecanoic acid is mixed at 30 °C with a large excess of 40\% aqueous ammonia solution. When the reaction is complete, water is added and the mixture is heated to 100 °C to remove the excess ammonia. The acid can be recrystallized from water. For further purification, the hydrochloride of 11-aminoundecanoic acid, which is available by acidification with hydrochloric acid, can be recrystallized from a methanol/ethyl acetate mixture. Aminoundecanoic acid. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=2432-99-7 (retrieved 2024-07-01) (CAS RN: 2432-99-7). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
3-Hydroxypentanoic acid
A short-chain fatty acid that is valeric acid in which one of the methylene hydrogens at position 3 has been replaced by a hydroxy group.