Exact Mass: 119.0531
Exact Mass Matches: 119.0531
Found 184 metabolites which its exact mass value is equals to given mass value 119.0531,
within given mass tolerance error 0.01 dalton. Try search metabolite list with more accurate mass tolerance error
0.001 dalton.
L-Threonine
L-threonine is an optically active form of threonine having L-configuration. It has a role as a nutraceutical, a micronutrient, a Saccharomyces cerevisiae metabolite, a plant metabolite, an Escherichia coli metabolite, a human metabolite, an algal metabolite and a mouse metabolite. It is an aspartate family amino acid, a proteinogenic amino acid, a threonine and a L-alpha-amino acid. It is a conjugate base of a L-threoninium. It is a conjugate acid of a L-threoninate. It is an enantiomer of a D-threonine. It is a tautomer of a L-threonine zwitterion. An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins. L-Threonine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). Threonine is an essential amino acid in humans (provided by food), Threonine is an important residue of many proteins, such as tooth enamel, collagen, and elastin. An important amino acid for the nervous system, threonine also plays an important role in porphyrin and fat metabolism and prevents fat buildup in the liver. Useful with intestinal disorders and indigestion, threonine has also been used to alleviate anxiety and mild depression. (NCI04) Threonine is an essential amino acid in humans. It is abundant in human plasma, particularly in newborns. Severe deficiency of threonine causes neurological dysfunction and lameness in experimental animals. Threonine is an immunostimulant which promotes the growth of thymus gland. It also can probably promote cell immune defense function. This amino acid has been useful in the treatment of genetic spasticity disorders and multiple sclerosis at a dose of 1 gram daily. It is highly concentrated in meat products, cottage cheese and wheat germ. The threonine content of most of the infant formulas currently on the market is approximately 20\\\\\\% higher than the threonine concentration in human milk. Due to this high threonine content the plasma threonine concentrations are up to twice as high in premature infants fed these formulas than in infants fed human milk. The whey proteins which are used for infant formulas are sweet whey proteins. Sweet whey results from cheese production. Threonine catabolism in mammals appears to be due primarily (70-80\\\\\\%) to the activity of threonine dehydrogenase (EC 1.1.1.103) that oxidizes threonine to 2-amino-3-oxobutyrate, which forms glycine and acetyl CoA, whereas threonine dehydratase (EC 4.2.1.16) that catabolizes threonine into 2-oxobutyrate and ammonia, is significantly less active. Increasing the threonine plasma concentrations leads to accumulation of threonine and glycine in the brain. Such accumulation affects the neurotransmitter balance which may have consequences for the brain development during early postnatal life. Thus, excessive threonine intake during infant feeding should be avoided. (A3450). An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins. See also: Amlisimod (monomer of) ... View More ... Threonine (Thr) or L-threonine 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-threonine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Threonine 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. Threonine is sometimes considered as a branched chain amino acid. Threonine was actually the last of the 20 amino acids to be discovered (in 1938). It was named threonine because it was similar in structure to threonic acid, a four-carbon monosaccharide. Threonine is an essential amino acid in humans, meaning the body cannot synthesize it and that it must be obtained from the diet. Foods high in threonine include cottage cheese, poultry, fish, meat, lentils, black turtle bean and sesame seeds. Adult humans require about 20 mg/kg body weight/day. In plants and microorganisms, threonine is synthesized from aspartic acid via alpha-aspartyl-semialdehyde and homoserine. In proteins, the threonine residue is susceptible to numerous posttranslational modifications. The hydroxyl side-chain can undergo O-linked glycosylation and phosphorylation through the action of a threonine kinase. Threonine is abundant in human plasma, particularly in newborns. Severe deficiency of threonine causes neurological dysfunction and lameness in experimental animals. Threonine is an immunostimulant which promotes the growth of thymus gland. It also can probably promote cell immune defense function. The threonine content of most of the infant formulas currently on the market is approximately 20\\\\\\% higher than the threonine concentration in human milk. Due to this high threonine content the plasma threonine concentrations are up to twice as high in premature infants fed these formulas than in infants fed human milk. The whey proteins which are used for infant formulas are sweet whey proteins. Sweet whey results from cheese production. Increasing the threonine plasma concentrations leads to accumulation of threonine and glycine in the brain. Such accumulation affects the neurotransmitter balance which may have consequences for the brain development during early postnatal life. Thus, excessive threonine intake during infant feeding should be avoided. (PMID 9853925). Threonine is metabolized in at least two ways. In many animals it is converted to pyruvate via threonine dehydrogenase. An intermediate in this pathway can undergo thiolysis with CoA to produce acetyl-CoA and glycine. In humans the gene for threonine dehydrogenase is an inactive pseudogene, so threonine is converted to alpha-ketobutyrate. From wide variety of protein hydrolysates. Dietary supplement, nutrient L-Threonine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=72-19-5 (retrieved 2024-07-01) (CAS RN: 72-19-5). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). DL-Threonine, an essential amino acid, has the potential to treat hypostatic leg ulceration[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
L-Homoserine
L-homoserine, also known as 2-amino-4-hydroxybutanoic acid or isothreonine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. L-homoserine is soluble (in water) and a moderately acidic compound (based on its pKa). L-homoserine can be found in common pea, which makes L-homoserine a potential biomarker for the consumption of this food product. L-homoserine can be found primarily in blood, feces, and urine, as well as in human prostate tissue. L-homoserine exists in all living species, ranging from bacteria to humans. In humans, L-homoserine is involved in the methionine metabolism. L-homoserine is also involved in several metabolic disorders, some of which include glycine n-methyltransferase deficiency, hypermethioninemia, cystathionine beta-synthase deficiency, and methylenetetrahydrofolate reductase deficiency (MTHFRD). Homoserine (also called isothreonine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2OH. L-Homoserine is not one of the common amino acids encoded by DNA. It differs from the proteinogenic amino acid serine by insertion of an additional -CH2- unit into the backbone. Homoserine, or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine . Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group, allowing it to chemically react to form a five-membered ring. This occurs at the point that amino acids normally join to their neighbours in a peptide bond. Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by living things. Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (wikipedia). Homoserine is also a microbial metabolite. L-Homoserine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=672-15-1 (retrieved 2024-07-02) (CAS RN: 672-15-1). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine. L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine.
2-Methylserine
Acquisition and generation of the data is financially supported in part by CREST/JST. KEIO_ID M025
4-Amino-3-hydroxybutyrate
4-Amino-3-hydroxybutyrate belongs to the class of organic compounds known as hydroxy fatty acids. These are fatty acids in which the chain bears a hydroxyl group.
L-Allothreonine
L-allothreonine is the L-enantiomer of allothreonine. It has a role as an Escherichia coli metabolite and a Saccharomyces cerevisiae metabolite. It is an enantiomer of a D-allothreonine. It is a tautomer of a L-allothreonine zwitterion. Allothreonine is the substrate of the enzyme Serine hydroxymethyltransferase1 (SHMT, EC 2.1.2.1), a human cytoplasmic mRNA binding protein. SHMT uses pyridoxal 5-phosphate (PLP) and tetrahydropteroylglutamate (H4PteGlu) as coenzymes and catalyzes the reversible interconversion of serine and glycine. In addition to these physiological reactions, SHMT also catalyzes, in the absence of H4PteGlu, the retroaldol cleavage of several 3-hydroxyamino acids, such as allothreonine. Allothreonine is a plant metabolite that appears in the human diet in variable concentrations depending on: plant species, physiological changes during plant growth, senescence, and reactions to environmental stress or to changes due to plant transformation (PMID:10858298, 10952545). Allothreonine is the substrate of the enzyme Serine hydroxymethyltransferase1 (SHMT, EC 2.1.2.1), a human cytoplasmic mRNA binding protein. SHMT uses pyridoxal 5-phosphate (PLP) and tetrahydropteroylglutamate (H4PteGlu) as coenzymes and catalyzes the reversible interconversion of serine and glycine. In addition to these physiological reactions, SHMT also catalyzes, in the absence of H4PteGlu, the retroaldol cleavage of several 3-hydroxyamino acids, such as allothreonine. Allothreonine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=144-98-9 (retrieved 2024-07-15) (CAS RN: 144-98-9). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). D-Allothreonine is the D type stereoisomer of Allothreonine. D-Allothreonine is a peptido-lipid derived from bacteria. D-Allothreonine, amide-linked to the D-galacturonic acid, is also a constituent in the polysaccharide[1][2]. L-Allothreonine (H-allo-Thr-OH) is an endogenous metabolite.
L-Threonine
An optically active form of threonine having L-configuration. MS2 deconvoluted using MS2Dec from all ion fragmentation data, MetaboLights identifier MTBLS1040; AYFVYJQAPQTCCC_STSL_0105_Threonine_8000fmol_180506_S2_LC02_MS02_275; Spectrum acquired as described in Naz et al 2017 PMID 28641411. Preparation and submission to MassBank of North America by Chaleckis R. and Tada I. MS2 deconvoluted using CorrDec from all ion fragmentation data, MetaboLights identifier MTBLS1040; Spectrum acquired as described in Naz et al 2017 PMID 28641411. Preparation and submission to MassBank of North America by Chaleckis R. and Tada I. CONFIDENCE standard compound; INTERNAL_ID 10 DL-Threonine, an essential amino acid, has the potential to treat hypostatic leg ulceration[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
Threonine #
2-amino-3-hydroxybutanoic acid is an alpha-amino acid that is butanoic acid substituted by an amino group at position 2 and a hydroxy group at position 3. It has a role as a plant metabolite. An alpha-amino acid that is butanoic acid substituted by an amino group at position 2 and a hydroxy group at position 3. D-Allothreonine is the D type stereoisomer of Allothreonine. D-Allothreonine is a peptido-lipid derived from bacteria. D-Allothreonine, amide-linked to the D-galacturonic acid, is also a constituent in the polysaccharide[1][2]. DL-Threonine, an essential amino acid, has the potential to treat hypostatic leg ulceration[1]. L-Allothreonine (H-allo-Thr-OH) is an endogenous metabolite. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
Aminoethoxyacetic acid
Aminoethoxyacetic acid is a metabolite of linezolid. Linezolid is a synthetic antibiotic used for the treatment of serious infections caused by Gram-positive bacteria that are resistant to several other antibiotics. A member of the oxazolidinone class of drugs, linezolid is active against most Gram-positive bacteria that cause disease, including streptococci, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). (Wikipedia)
Hydroxyethyl glycine
Hydroxyethyl glycine is a metabolite of linezolid. Linezolid is a synthetic antibiotic used for the treatment of serious infections caused by Gram-positive bacteria that are resistant to several other antibiotics. A member of the oxazolidinone class of drugs, linezolid is active against most Gram-positive bacteria that cause disease, including streptococci, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). (Wikipedia)
2-Aminoethyl carbamimidothioate
D020011 - Protective Agents > D011837 - Radiation-Protective Agents
D-Threonine
Alpha-amino-beta-hydroxybutyric acid, also known as α-amino-β-hydroxybutyrate, is a member of the class of compounds known as alpha amino acids. Alpha amino acids are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Alpha-amino-beta-hydroxybutyric acid is soluble (in water) and a moderately acidic compound (based on its pKa). Alpha-amino-beta-hydroxybutyric acid can be found in peanut, which makes alpha-amino-beta-hydroxybutyric acid a potential biomarker for the consumption of this food product.
3-dimethylsulfoniopropionaldehyde
3-dimethylsulfoniopropionaldehyde, also known as dmsp-aldehyde, is a member of the class of compounds known as alpha-hydrogen aldehydes. Alpha-hydrogen aldehydes are aldehydes with the general formula HC(H)(R)C(=O)H, where R is an organyl group. 3-dimethylsulfoniopropionaldehyde is slightly soluble (in water) and an extremely weak acidic compound (based on its pKa). 3-dimethylsulfoniopropionaldehyde can be found in a number of food items such as chinese chestnut, welsh onion, dandelion, and parsnip, which makes 3-dimethylsulfoniopropionaldehyde a potential biomarker for the consumption of these food products.
Threonine
COVID info from PDB, Protein Data Bank Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS DL-Threonine, an essential amino acid, has the potential to treat hypostatic leg ulceration[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
1H-Benzotriazole
CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 2978; ORIGINAL_PRECURSOR_SCAN_NO 2976 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 2990; ORIGINAL_PRECURSOR_SCAN_NO 2988 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 2960; ORIGINAL_PRECURSOR_SCAN_NO 2958 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 2969; ORIGINAL_PRECURSOR_SCAN_NO 2967 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6248; ORIGINAL_PRECURSOR_SCAN_NO 6246 ORIGINAL_ACQUISITION_NO 6248; ORIGINAL_PRECURSOR_SCAN_NO 6246; CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6290; ORIGINAL_PRECURSOR_SCAN_NO 6288 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6292; ORIGINAL_PRECURSOR_SCAN_NO 6290 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6308; ORIGINAL_PRECURSOR_SCAN_NO 6305 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6318; ORIGINAL_PRECURSOR_SCAN_NO 6317 CONFIDENCE standard compound; INTERNAL_ID 634; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 6317; ORIGINAL_PRECURSOR_SCAN_NO 6314 CONFIDENCE standard compound; INTERNAL_ID 2414 CONFIDENCE Reference Standard (Level 1); INTERNAL_ID 1078 CONFIDENCE standard compound; INTERNAL_ID 4050 CONFIDENCE standard compound; INTERNAL_ID 4177 CONFIDENCE standard compound; INTERNAL_ID 8197 CONFIDENCE standard compound; EAWAG_UCHEM_ID 166
3-dimethylsulfoniopropionaldehyde
A sulfonium compound that is dimethysulfonium with a 3-oxopropyl substituent.
Benzotriazole
CONFIDENCE standard compound; INTERNAL_ID 2 CONFIDENCE standard compound; INTERNAL_ID 8799 CONFIDENCE Reference Standard (Level 1)
Threonine
An alpha-amino acid in which one of the hydrogens attached to the alpha-carbon of glycine is substituted by a 1-hydroxyethyl group. Acquisition and generation of the data is financially supported by the Max-Planck-Society L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1]. L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
L-β-homoserine
Acquisition and generation of the data is financially supported in part by CREST/JST.
D-β-homoserine
Acquisition and generation of the data is financially supported in part by CREST/JST.
Homoserine
An alpha-amino acid that is glycine substituted at the alpha-position by a 2-hydroxyethyl group. Homoserine, also known as L-isomer of homoserine or 2-amino-4-hydroxybutanoic acid, is a member of the class of compounds known as alpha amino acids. Alpha amino acids are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Homoserine is soluble (in water) and a moderately acidic compound (based on its pKa). Homoserine can be found in common pea and ginkgo nuts, which makes homoserine a potential biomarker for the consumption of these food products. Homoserine (also called isothreonine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2OH. L-Homoserine is not one of the common amino acids encoded by DNA. It differs from the proteinogenic amino acid serine by insertion of an additional -CH2- unit into the backbone. Homoserine, or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine . L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine. L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine.
L-Allothreonine
The L-enantiomer of allothreonine. L-Allothreonine (H-allo-Thr-OH) is an endogenous metabolite.
L-Homoserine
The L-enantiomer of homoserine. L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine. L-Homoserine is a non - protein amino acid, which is an important biosynthetic intermediate of threonine, methionine and lysine.
Allothreonine
D-Allothreonine is the D type stereoisomer of Allothreonine. D-Allothreonine is a peptido-lipid derived from bacteria. D-Allothreonine, amide-linked to the D-galacturonic acid, is also a constituent in the polysaccharide[1][2]. L-Allothreonine (H-allo-Thr-OH) is an endogenous metabolite.
O-Methylserine
A serine derivative that is L-serine with a methyl group replacing the hydrogen on the hydroxy side chain.
Kinase(Phosphorylating), Protein Serine or Threonine
D-Allothreonine
The D-enantiomer of allothreonine. It occurs as a component of peptido-lipids in certain bacteria. D-Allothreonine is the D type stereoisomer of Allothreonine. D-Allothreonine is a peptido-lipid derived from bacteria. D-Allothreonine, amide-linked to the D-galacturonic acid, is also a constituent in the polysaccharide[1][2].
2-Amino-2-hydroxybutanoic acid
An alpha-amino acid that is butanoic acid substituted by an amino and a hydroxy group at position 2.
D-Threonine
An optically active form of threonine having D-configuration. DL-Threonine, an essential amino acid, has the potential to treat hypostatic leg ulceration[1].
L-threonine zwitterion
Zwitterionic form of L-threonine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3.
2-methyl-L-serine zwitterion
An amino acid zwitterion obtained from the transfer of a proton from the carboxy group to the amino group of 2-methyl-L-serine. Major species at pH 7.3.
D-threonine zwitterion
A D-alpha-amino acid zwitterion that is D-threonine in which a proton has been transferred from the carboxy group to the amino group. It is the major species at pH 7.3.
D-allothreonine zwitterion
A D-alpha-amino acid zwitterion that is D-allothreonine in which a proton has been transferred from the carboxy group to the amino group. It is the major species at pH 7.3.
D-homoserine zwitterion
A D-alpha-amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of D-homoserine; major species at pH 7.3.
gamma-Amino-beta-hydroxybutyric acid
A gamma-amino acid comprising 4-aminobutyric acid having a 2-hydroxy substituent.
