Threonic acid

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l-Threonic acid
L-threonic acid.png
IUPAC name
(2R,3S)-2,3,4-Trihydroxybutanoic acid
Other names
3D model (JSmol)
PubChem CID
Molar mass 136.103 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Threonic acid is a sugar acid derived from threose. The l-isomer is a metabolite of ascorbic acid (vitamin C). [1] One study suggested that because l-threonate inhibits DKK1 expression in vitro, it may have potential in treatment of androgenic alopecia. [2]

Sugar acid

Sugar acids are monosaccharides with a carboxyl group.

Threose chemical compound

Threose is a four-carbon monosaccharide with molecular formula C4H8O4. It has a terminal aldehyde group rather than a ketone in its linear chain, and so is considered part of the aldose family of monosaccharides. The threose name can be used to refer to both the D- and L-stereoisomers, and more generally to the racemic mixture (D/L-, equal parts D- and L-) as well as to the more generic threose structure (absolute stereochemistry unspecified).

In chemistry, isomers are ions or molecules with identical formulas but distinct structures. Isomers do not necessarily share similar properties. Two main forms of isomerism are structural isomerism and stereoisomerism.

Related Research Articles

Vitamin C nutrient found in citrus fruits and other foods

Vitamin C, also known as ascorbic acid and l-ascorbic acid, is a vitamin found in various foods and sold as a dietary supplement. It is used to prevent and treat scurvy. Vitamin C is an essential nutrient involved in the repair of tissue and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant.

Tetrahydrobiopterin chemical compound

Tetrahydrobiopterin (BH4, THB), also known as sapropterin, is a cofactor of the three aromatic amino acid hydroxylase enzymes, used in the degradation of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT), melatonin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and is a cofactor for the production of nitric oxide (NO) by the nitric oxide synthases. Chemically, its structure is that of a reduced pteridine derivative.

Dehydroascorbic acid (DHA) is an oxidized form of ascorbic acid. It is actively imported into the endoplasmic reticulum of cells via glucose transporters. It is trapped therein by reduction back to ascorbate by glutathione and other thiols. The (free) chemical radical semidehydroascorbic acid (SDA) also belongs to the group of oxidized ascorbic acids.

L-gulonolactone oxidase is an enzyme that produces vitamin C, but is non-functional in Haplorrhini, in some bats, and in guinea pigs. It catalyzes the reaction of L-gulono-1,4-lactone with oxygen to L-xylo-hex-3-gulonolactone and hydrogen peroxide. It uses FAD as a cofactor. The L-xylo-hex-3-gulonolactone (2-keto-gulono-gamma-lactone) is able to convert to hexuronic acid spontaneously, without enzymatic action.

Phytol is an acyclic diterpene alcohol that can be used as a precursor for the manufacture of synthetic forms of vitamin E and vitamin K1. In ruminants, the gut fermentation of ingested plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats. In shark liver it yields pristane.

Kynurenine chemical compound

l-Kynurenine is a metabolite of the amino acid l-tryptophan used in the production of niacin.

Sodium ascorbate chemical compound

Sodium ascorbate is one of a number of mineral salts of ascorbic acid (vitamin C). The molecular formula of this chemical compound is C6H7NaO6. As the sodium salt of ascorbic acid, it is known as a mineral ascorbate. It has not been demonstrated to be more bioavailable than any other form of vitamin C supplement.

CYP2C9 protein-coding gene in the species Homo sapiens

Cytochrome P450 2C9 is an enzyme that in humans is encoded by the CYP2C9 gene.

Kynurenic acid chemical compound

Kynurenic acid is a product of the normal metabolism of amino acid L-tryptophan. It has been shown that kynurenic acid possesses neuroactive activity. It acts as an antiexcitotoxic and anticonvulsant, most likely through acting as an antagonist at excitatory amino acid receptors. Because of this activity, it may influence important neurophysiological and neuropathological processes. As a result, kynurenic acid has been considered for use in therapy in certain neurobiological disorders. Conversely, increased levels of kynurenic acid have also been linked to certain pathological conditions.

Retinoid X receptor gamma protein-coding gene in the species Homo sapiens

Retinoic acid receptor gamma (RXR-gamma), also known as NR2B3 is a nuclear receptor that in humans is encoded by the RXRG gene.

GPR31 protein-coding gene in the species Homo sapiens

G-protein coupled receptor 31 also known as 12-(S)-HETE receptor is a protein that in humans is encoded by the GPR31 gene. The human gene is located on chromosome 6q27 and encodes a G-protein coupled receptor protein composed of 319 amino acids.

Leukotriene B<sub>4</sub> receptor 2 protein-coding gene in the species Homo sapiens

Leukotriene B4 receptor 2, also known as BLT2, BLT2 receptor, and BLTR2, is a Integral membrane protein that is encoded by the LTB4R2 gene in humans and the Ltbr2 gene in mice.

DKK1 protein-coding gene in the species Homo sapiens

Dickkopf-related protein 1 is a protein that in humans is encoded by the DKK1 gene.

KCNK9 protein-coding gene in the species Homo sapiens

Potassium channel subfamily K member 9 is a protein that in humans is encoded by the KCNK9 gene.

12-Hydroxyeicosatetraenoic acid chemical compound

12-Hydroxyeicosatetraenoic acid (12-HETE) is a derivative of the 20 carbon polyunsaturated fatty acid, arachidonic acid, containing a Hydroxyl residue at carbon 12 and a 5Z,8Z,10E,14Z Cis–trans isomerism configuration in its four double bonds. It was first found as a product of arachidonic acid metabolism made by human and bovine platelets through their 12S-lipoxygenase enzyme(s). However, the term 12-HETE is ambiquous in that it has been used to indicate not only the initially detected "S" stereoisomer, 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid, made by platelets, but also the later detected "R" stereoisomer, 12(R)-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid made by other tissues through their 12R-lipoxygenase enzyme, ALOX12B. The two isomers, either directly or after being further metabolized, have been suggested to be involved in a variety of human physiological and pathological reactions. Unlike hormones which are secreted by cells, travel in the circulation to alter the behavior of distant cells, and thereby act as Endocrine signalling agents, these arachidonic acid metabolites act locally as Autocrine signalling and/or Paracrine signaling agents to regulate the behavior of their cells of origin or of nearby cells, respectively. In these roles, they may amplify or dampen, expand or contract cellular and tissue responses to disturbances.

Human Metabolome Database database of human metabolites

The Human Metabolome Database (HMDB) is a comprehensive, high-quality, freely accessible, online database of small molecule metabolites found in the human body. Created by the Human Metabolome Project funded by Genome Canada. One of the first dedicated metabolomics databases, the HMDB facilitates human metabolomics research, including the identification and characterization of human metabolites using NMR spectroscopy, GC-MS spectrometry and LC/MS spectrometry. To aid in this discovery process, the HMDB contains three kinds of data: 1) chemical data, 2) clinical data, and 3) molecular biology/biochemistry data. The chemical data includes 41,514 metabolite structures with detailed descriptions along with nearly 10,000 NMR, GC-MS and LC/MS spectra.

L-galactonolactone dehydrogenase (EC, galactonolactone dehydrogenase, L-galactono-gamma-lactone dehydrogenase, L-galactono-gamma-lactone:ferricytochrome-c oxidoreductase, GLDHase, GLDase) is an enzyme with systematic name L-galactono-1,4-lactone:ferricytochrome-c oxidoreductase. This enzyme catalyses the following chemical reaction

12-Hydroxyheptadecatrienoic acid Chemical compound

12-Hydroxyheptadecatrenoic acid is a 17 carbon metabolite of the 20 carbon polyunsaturated fatty acid, arachidonic acid. It was first detected and structurally defined by P. Wlodawer, Bengt I. Samuelsson, and M. Hamberg as a product of arachidonic acid metabolism made by microsomes isolated from sheep seminal vesicle glands and by intact human platelets. 12-HHT is less ambiguously termed 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid to indicate the S stereoisomerism of its 12-hydroxyl residue and the Z, E, and E cis-trans isomerism of its three double bonds. The metabolite was for many years thought to be merely a biologically inactive byproduct of prostaglandin synthesis. More recent studies, however, have attached potentially important activity to it.

13-Hydroxyoctadecadienoic acid chemical compound

13-Hydroxyoctadecadienoic acid (13-HODE) is the commonly used term for 13(S)-hydroxy-9Z,11E-octadecadienoic acid. The production of 13(S)-HODE is often accompanied by the production of its stereoisomer, 13(R)-hydroxy-9Z,11E-octadecadienoic acid. The adjacent figure gives the structure for the (S) stereoisomer of 13-HODE. Two other naturally occurring 13-HODEs that may accompany the production of 13(S)-HODE are its cis-trans isomers viz., 13(S)-hydroxy-9E,11E-octadecadienoic acid and 13(R)-hydroxy-9E,11E-octadecadienoic acid. Studies credit 13(S)-HODE with a range of clinically relevant bioactivities; recent studies have assigned activities to 13(R)-HODE that differ from those of 13(S)-HODE; and other studies have proposed that one or more of these HODEs mediate physiological and pathological responses, are markers of various human diseases, and/or contribute to the progression of certain diseases in humans. Since, however, many studies on the identification, quantification, and actions of 13(S)-HODE in cells and tissues have employed methods that did not distinguish between these isomers, 13-HODE is used here when the actual isomer studied is unclear.

Intravenous ascorbic acid

Intravenous Ascorbic Acid, is a type of therapy that delivers soluble ascorbic acid directly into the bloodstream, either administered via injection or infusion. Intravenous ascorbic acid is used as a dietary supplement for nutritional deficiencies and also, as complementary therapy to cancer treatments. The efficacy of intravenous ascorbic acid as a cancer treatment has been a controversial topic since the emergence of misleading data in the 1970s; however, new research in the 21st century has shown promising potential in oncological therapeutic treatments.


  1. S Englard and S Seifter (1986). "The Biochemical Functions of Ascorbic Acid". Annual Review of Nutrition. 6: 365–406. doi:10.1146/ PMID   3015170.
  2. Kwack, M. H.; Ahn, J. S.; Kim, M. K.; Kim, J. C.; Sun, Y. K. (2010). "Preventable effect of L-threonate, an ascorbate metabolite, on androgen-driven balding via repression of dihydrotestosteroneinduced dickkopf-1 expression in human hair dermal papilla cells". BMB Reports. 43 (10): 688–692. doi:10.5483/BMBRep.2010.43.10.688. PMID   21034532.