Gene Association: CSAD

UniProt Search: CSAD (PROTEIN_CODING)
Function Description: cysteine sulfinic acid decarboxylase

found 19 associated metabolites with current gene based on the text mining result from the pubmed database.

Taurine

2-aminoethanesulfonic acid

C2H7NO3S (125.0147)


Essential nutrient obtained from diet and by in vivo synthysis from methionine and cysteine. Present in meats, fish, legumes, human milk, molluscs and other foods. Dietary supplement, e.g. in Red Bull drink. Taurine is a sulfur amino acid like methionine, cystine, cysteine and homocysteine. It is a lesser-known amino acid because it is not incorporated into the structural building blocks of protein. Yet taurine is an essential amino acid in pre-term and newborn infants of humans and many other species. Adults can synthesize their own taurine, yet are probably dependent in part on dietary taurine. Taurine is abundant in the brain, heart, breast, gallbladder and kidney and has important roles in health and disease in these organs. Taurine has many diverse biological functions serving as a neurotransmitter in the brain, a stabilizer of cell membranes and a facilitator in the transport of ions such as sodium, potassium, calcium and magnesium. Taurine is highly concentrated in animal and fish protein, which are good sources of dietary taurine. It can be synthesized by the body from cysteine when vitamin B6 is present. Deficiency of taurine occurs in premature infants and neonates fed formula milk, and in various disease states. Inborn errors of taurine metabolism have been described. OMIM 168605, an unusual neuropsychiatric disorder inherited in an autosomal dominant fashion through 3 generations of a family. Symptoms began late in the fifth decade in 6 affected persons and death occurred after 4 to 6 years. The earliest and most prominent symptom was mental depression not responsive to antidepressant drugs or electroconvulsive therapy. Sleep disturbances, exhaustion and marked weight loss were features. Parkinsonism developed later, and respiratory failure occurred terminally. OMIM 145350 describes congestive cardiomyopathy and markedly elevated urinary taurine levels (about 5 times normal). Other family members had late or holosystolic mitral valve prolapse and elevated urinary taurine values (about 2.5 times normal). In 2 with mitral valve prolapse, congestive cardiomyopathy eventually developed while the amounts of urinary taurine doubled. Taurine, after GABA, is the second most important inhibitory neurotransmitter in the brain. Its inhibitory effect is one source of taurines anticonvulsant and antianxiety properties. It also lowers glutamic acid in the brain, and preliminary clinical trials suggest taurine may be useful in some forms of epilepsy. Taurine in the brain is usually associated with zinc or manganese. The amino acids alanine and glutamic acid, as well as pantothenic acid, inhibit taurine metabolism while vitamins A and B6, zinc and manganese help build taurine. Cysteine and B6 are the nutrients most directly involved in taurine synthesis. Taurine levels have been found to decrease significantly in many depressed patients. One reason that the findings are not entirely clear is because taurine is often elevated in the blood of epileptics who need it. It is often difficult to distinguish compensatory changes in human biochemistry from true metabolic or deficiency disease. Low levels of taurine are found in retinitis pigmentosa. Taurine deficiency in experimental animals produces degeneration of light-sensitive cells. Therapeutic applications of taurine to eye disease are likely to be forthcoming. Taurine has many important metabolic roles. Supplements can stimulate prolactin and insulin release. The parathyroid gland makes a peptide hormone called glutataurine (glutamic acid-taurine), which further demonstrates taurines role in endocrinology. Taurine increases bilirubin and cholesterol excretion in bile, critical to normal gallbladder function. It seems to inhibit the effect of morphine and potentiates the effects of opiate antagonists. Low plasma taurine levels have been found in a variety of conditions, i.e., depression, hypertension, hypothyroidism, gout, institutionalized patients, infertility, obesity, kidney fa... Taurine is a sulfur amino acid like methionine, cystine, cysteine, and homocysteine. It is a lesser-known amino acid because it is not incorporated into the structural building blocks of protein. Yet taurine is an essential amino acid in pre-term and newborn infants of humans and many other species. Adults can synthesize their own taurine, yet are probably dependent, in part, on dietary taurine. Taurine is abundant in the brain, heart, breast, gallbladder, and kidney and has important roles in health and disease in these organs. Taurine has many diverse biological functions including serving as a neurotransmitter in the brain, a stabilizer of cell membranes, and a facilitator in the transport of ions such as sodium, potassium, calcium, and magnesium. Taurine is highly concentrated in animal and fish protein, which are good sources of dietary taurine. It can be synthesized by the body from cysteine when vitamin B6 is present. Deficiency of taurine occurs in premature infants, neonates fed formula milk, and various disease states. Several inborn errors of taurine metabolism have been described. Perry syndrome is an unusual neuropsychiatric disorder inherited in an autosomal dominant fashion through three generations of a family. Symptoms began late in the fifth decade in 6 affected persons and death occurred after 4 to 6 years. The earliest and most prominent symptom was mental depression that was not responsive to antidepressant drugs or electroconvulsive therapy. Sleep disturbances, exhaustion, and marked weight loss were features. Parkinsonism developed later, and respiratory failure occurred terminally (OMIM: 168605). Hypertaurinuric cardiomyopathy describes congestive cardiomyopathy and markedly elevated urinary taurine levels (about 5 times normal). Other family members had late or holosystolic mitral valve prolapse and elevated urinary taurine values (about 2.5 times normal). In two with mitral valve prolapse, congestive cardiomyopathy eventually developed while the amounts of urinary taurine doubled (OMIM: 145350). Taurine, after GABA, is the second most important inhibitory neurotransmitter in the brain. Its inhibitory effect is one source of taurines anticonvulsant and antianxiety properties. It also lowers glutamic acid in the brain, and preliminary clinical trials suggest taurine may be useful in some forms of epilepsy. Taurine in the brain is usually associated with zinc or manganese. The amino acids alanine and glutamic acid, as well as pantothenic acid, inhibit taurine metabolism while vitamins A and B6, zinc, and manganese help build taurine. Cysteine and B6 are the nutrients most directly involved in taurine synthesis. Taurine levels have been found to decrease significantly in many depressed patients. One reason that the findings are not entirely clear is that taurine is often elevated in the blood of epileptics who need it. It is often difficult to distinguish compensatory changes in human biochemistry from true metabolic or deficiency disease. Low levels of taurine are found in retinitis pigmentosa. Taurine deficiency in experimental animals produces degeneration of light-sensitive cells. Therapeutic applications of taurine to eye disease are likely to be forthcoming. Taurine has many important metabolic roles. Supplements can stimulate prolactin and insulin release. The parathyroid gland makes a peptide hormone called glutataurine (glutamic acid-taurine), which further demonstrates taurines role in endocrinology. Taurine increases bilirubin and cholesterol excretion in bile, critical to normal gallbladder function. It seems to inhibit the effect of morphine and potentiates the effects of opiate antagonists. Low plasma taurine levels have been found in a variety of conditions, i.e. depression, hypertension, hypothyroidism, gout, institutionalized patients, infertility, obesity, kidney failure, and others (http://www.dcnutrition.com/AminoAcids/). Moreover, taurine is found to be associated with maple syrup uri... Large white crystals or white powder. Taurine is an amino sulfonic acid that is the 2-amino derivative of ethanesulfonic acid. It is a naturally occurring amino acid derived from methionine and cysteine metabolism. An abundant component of fish- and meat-based foods, it has been used as an oral supplement in the treatment of disorders such as cystic fibrosis and hypertension. It has a role as a human metabolite, an antioxidant, a mouse metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a glycine receptor agonist, a nutrient and a radical scavenger. It is a conjugate acid of a 2-aminoethanesulfonate. It is a tautomer of a taurine zwitterion. Taurine, whose chemical name is 2-aminoethanesulfonic acid, is one of the most abundant amino acids in several organs. It plays important role in essential biological processes. This conditional amino acid can be either be manufactured by the body or obtained in the diet mainly by the consumption of fish and meat. The supplements containing taurine were FDA approved by 1984 and they are hypertonic injections composed by cristalline amino acids. Taurine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids. See also: ... View More ... An amino sulfonic acid that is the 2-amino derivative of ethanesulfonic acid. It is a naturally occurring amino acid derived from methionine and cysteine metabolism. An abundant component of fish- and meat-based foods, it has been used as an oral supplement in the treatment of disorders such as cystic fibrosis and hypertension. [Spectral] Taurine (exact mass = 125.01466) and L-Threonine (exact mass = 119.05824) and 4-Hydroxy-L-proline (exact mass = 131.05824) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] Taurine (exact mass = 125.01466) and L-Glutamate (exact mass = 147.05316) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Taurine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=107-35-7 (retrieved 2024-06-29) (CAS RN: 107-35-7). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Taurine, a sulphur-containing amino acid and an organic osmolyte involved in cell volume regulation, provides a substrate for the formation of bile salts, and plays a role in the modulation of intracellular free calcium concentration. Taurine has the ability to activate autophagy in adipocytes[1][2][3]. Taurine, a sulphur-containing amino acid and an organic osmolyte involved in cell volume regulation, provides a substrate for the formation of bile salts, and plays a role in the modulation of intracellular free calcium concentration. Taurine has the ability to activate autophagy in adipocytes[1][2][3].

   

S-Methylcysteine

S-Methyl-L-cysteine, substrate for methionine sulfoxide reductase A

C4H9NO2S (135.0354)


S-methylcysteine is a cysteine derivative that is L-cysteine in which the hydrogen attached to the sulfur is replaced by a methyl group. It has a role as a human urinary metabolite and a plant metabolite. It is a tautomer of a S-methylcysteine zwitterion. S-Methyl-L-cysteine is a natural product that acts as a substrate in the catalytic antioxidant system mediated by methionine sulfoxide reductase A (MSRA), with antioxidative, neuroprotective, and anti-obesity activities.

   

3-Sulfinoalanine

(2R)-2-amino-3-[(R)-sulfino]propanoic acid

C3H7NO4S (153.0096)


3-Sulfinoalanine or cysteinesulfinic acid is a N-methyl-D-aspartate agonist. It is a product of cysteine dioxygenase or CDO [EC 1.13.11.20]. In humans cysteine catabolism is tightly regulated via regulation of cysteine dioxygenase (CDO) levels in the liver, with the turnover of CDO protein being dramatically decreased when intracellular cysteine levels increase. This occurs in response to changes in the intracellular cysteine concentration via changes in the rate of CDO ubiquitination and degradation. Expressed at high levels in the liver with lower levels in the kidney, brain, and lung, cysteine dioxygenase catalyzes the addition of molecular oxygen to the sulfhydryl group of cysteine, yielding cysteinesulfinic acid. The oxidative catabolism of cysteine to cysteinesulfinate by CDO represents an irreversible loss of cysteine from the free amino acid pool. Once generated, cysteinesulfinate is shuttled into several pathways including hypotaurine/taurine synthesis, sulfite/sulfate production, and the generation of pyruvate. [HMDB] 3-Sulfinoalanine or cysteinesulfinic acid is an N-methyl-D-aspartate agonist. It is a product of cysteine dioxygenase or CDO (EC 1.13.11.20). In humans, cysteine catabolism is tightly regulated via regulation of cysteine dioxygenase (CDO) levels in the liver, with the turnover of CDO protein being dramatically decreased when intracellular cysteine levels increase. This occurs in response to changes in the intracellular cysteine concentration via changes in the rate of CDO ubiquitination and degradation. Expressed at high levels in the liver with lower levels in the kidney, brain, and lung, cysteine dioxygenase catalyzes the addition of molecular oxygen to the sulfhydryl group of cysteine, yielding cysteinesulfinic acid. The oxidative catabolism of cysteine to cysteinesulfinate by CDO represents an irreversible loss of cysteine from the free amino acid pool. Once generated, cysteinesulfinate is shuttled into several pathways including hypotaurine/taurine synthesis, sulfite/sulfate production, and the generation of pyruvate. [Spectral] 3-Sulfino-L-alanine (exact mass = 153.00958) and L-Isoleucine (exact mass = 131.09463) and alpha-D-Glucose 6-phosphate (exact mass = 260.02972) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] 3-Sulfino-L-alanine (exact mass = 153.00958) and alpha-D-Glucose 6-phosphate (exact mass = 260.02972) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] 3-Sulfino-L-alanine (exact mass = 153.00958) and sn-Glycerol 3-phosphate (exact mass = 172.01367) 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. KEIO_ID C015 L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1]. L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1].

   

Hypotaurine

2-aminoethane-1-sulfinic acid

C2H7NO2S (109.0197)


Hypotaurine belongs to the class of organic compounds known as sulfinic acids. Sulfinic acids are compounds containing a sulfinic acid functional group, with the general structure RS(=O)OH (R = organyl, not H). Hypotaurine exists in all living species, ranging from bacteria to humans. Within humans, hypotaurine participates in a number of enzymatic reactions. In particular, hypotaurine can be biosynthesized from cysteamine; which is catalyzed by the enzyme 2-aminoethanethiol dioxygenase. In addition, hypotaurine can be biosynthesized from 3-sulfinoalanine through its interaction with the enzyme cysteine sulfinic acid decarboxylase. In humans, hypotaurine is involved in taurine and hypotaurine metabolism. [Spectral] Hypotaurine (exact mass = 109.01975) and Cytosine (exact mass = 111.04326) 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. Hypotaurine is a product of enzyme cysteamine dioxygenase [EC 1.13.11.19] in taurine and hypotaurine metabolism pathway (KEGG). It may function as an antioxidant and a protective agent under physiological conditions (PMID 14992269). [HMDB] Hypotaurine (2-aminoethanesulfinic acid), an intermediate in taurine biosynthesis from cysteine in astrocytes, is an endogenous inhibitory amino acid of the glycine receptor. Antioxidant[1].

   

Cysteic acid

2-Amino-3-sulfopropionic acid

C3H7NO5S (169.0045)


Cysteic acid is a crystalline amino acid formed in the oxidation of cysteine; it is a precursor of taurine. A crystalline amino acid formed in the oxidation of cysteine; it is a precursor of taurine. [HMDB]

   

Beta-Alanine

Omega-aminopropionic acid

C3H7NO2 (89.0477)


beta-Alanine is the only naturally occurring beta-amino acid - an amino acid in which the amino group is at the beta-position from the carboxylate group. It is formed in vivo by the degradation of dihydrouracil and carnosine. It is a component of the naturally occurring peptides carnosine and anserine and also of pantothenic acid (vitamin B-5), which itself is a component of coenzyme A. Under normal conditions, beta-alanine is metabolized into acetic acid. beta-Alanine can undergo a transanimation reaction with pyruvate to form malonate-semialdehyde and L-alanine. The malonate semialdehyde can then be converted into malonate via malonate-semialdehyde dehydrogenase. Malonate is then converted into malonyl-CoA and enter fatty acid biosynthesis. Since neuronal uptake and neuronal receptor sensitivity to beta-alanine have been demonstrated, beta-alanine may act as a false transmitter replacing gamma-aminobutyric acid. When present in sufficiently high levels, beta-alanine can act as a neurotoxin, a mitochondrial toxin, and a metabotoxin. A neurotoxin is a compound that damages the brain or nerve tissue. A mitochondrial toxin is a compound that damages mitochondria and reduces cellular respiration as well as oxidative phosphorylation. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of beta-alanine are associated with at least three inborn errors of metabolism, including GABA-transaminase deficiency, hyper-beta-alaninemia, and methylmalonate semialdehyde dehydrogenase deficiency. beta-Alanine is a central nervous system (CNS) depressant and is an inhibitor of GABA transaminase. The associated inhibition of GABA transaminase and displacement of GABA from CNS binding sites can also lead to GABAuria (high levels of GABA in the urine) and convulsions. In addition to its neurotoxicity, beta-alanine reduces cellular levels of taurine, which are required for normal respiratory chain function. Cellular taurine depletion is known to reduce respiratory function and elevate mitochondrial superoxide generation, which damages mitochondria and increases oxidative stress (PMID: 27023909). Individuals suffering from mitochondrial defects or mitochondrial toxicity typically develop neurotoxicity, hypotonia, respiratory distress, and cardiac failure. beta-Alanine is a biomarker for the consumption of meat, especially red meat. Widely distributed in plants including algae, fungi and many higher plants. Flavouring ingredient β-Alanine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=107-95-9 (retrieved 2024-07-01) (CAS RN: 107-95-9). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer. β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer. β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer.

   

1-Pyrroline-5-carboxylic acid

delta-1-Pyrroline-5-carboxylate, 14C-labeled, (+-)-isomer

C5H7NO2 (113.0477)


1-Pyrroline-5-carboxylic acid (CAS: 2906-39-0) is an enamine or an imino acid that forms upon the spontaneous dehydration of L-glutamate gamma-semialdehyde in aqueous solutions. The stereoisomer (S)-1-pyrroline-5-carboxylate is an intermediate in glutamate metabolism, arginine degradation, and proline biosynthesis and degradation. It can also be converted into or be formed from three amino acids: L-glutamate, L-ornithine, and L-proline. In particular, it is synthesized via the oxidation of proline by pyrroline-5-carboxylate reductase 1 (PYCR1) (EC 1.5.1.2) or by proline dehydrogenase (PRODH) (EC 1.5.99.8). It is hydrolyzed into L-glutamate by delta-1-pyrroline-5-carboxylate dehydrogenase (ALDH4A1) (EC 1.5.1.12). It is also one of the few metabolites that can act as a precursor to other metabolites of both the urea cycle and the tricarboxylic acid (TCA) cycle. Under certain conditions, pyrroline-5-carboxylate can act as a neurotoxin and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of pyrroline-5-carboxylate are associated with at least five inborn errors of metabolism, including hyperprolinemia type I, hyperprolinemia type II, iminoglycinuria, prolinemia type II, and pyruvate carboxylase deficiency. Hyperprolinemia type II results in high levels of pyrroline-5-carboxylate. People with hyperprolinemia type II have signs and symptoms that vary in severity, but they are more likely than type I to have seizures or intellectual disability. Pyrroline-5-carboxylate is highly reactive and excess quantities have been shown to cause cell death and apoptosis (PMID: 15548746). (s)-1-pyrroline-5-carboxylate, also known as delta-1-pyrroline-5-carboxylate, (+-)-isomer, belongs to alpha amino acids and derivatives class of compounds. Those are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof (s)-1-pyrroline-5-carboxylate is soluble (in water) and a moderately acidic compound (based on its pKa). (s)-1-pyrroline-5-carboxylate can be found in a number of food items such as beech nut, mango, oyster mushroom, and other bread, which makes (s)-1-pyrroline-5-carboxylate a potential biomarker for the consumption of these food products (s)-1-pyrroline-5-carboxylate may be a unique E.coli metabolite.

   

L-Cysteinesulfinic acid

2-amino-3-sulfinopropanoic acid

C3H7NO4S (153.0096)


L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1]. L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1].

   

S-methylcysteine

S-methylcysteine, hydrochloride, (L-Cys)-isomer

C4H9NO2S (135.0354)


Methylcysteine is one of the identified number of bioactive substances in garlic that are water soluble (PMID 16484549). It has been suggested that the use of these organosulfur agents derived from garlic could protect partially oxidized and glycated LDL or plasma against further oxidative and glycative deterioration, which might benefit patients with diabetic-related vascular diseases (PMID 15161248). It may also exert some chemopreventive effects on chemical carcinogenesis. However, it should be borne in mind that may also demonstrate promotion potential, depending on the organ examined (PMID 9591199). Methylcystein is a biomarker for the consumption of dried and cooked beans. S-n-methylcysteine, also known as (2r)-2-amino-3-(methylsulfanyl)propanoic acid or 3-(methylthio)-L-alanine, is a member of the class of compounds known as L-cysteine-s-conjugates. L-cysteine-s-conjugates are compounds containing L-cysteine where the thio-group is conjugated. S-n-methylcysteine is soluble (in water) and a moderately acidic compound (based on its pKa). S-n-methylcysteine can be found in soft-necked garlic, which makes S-n-methylcysteine a potential biomarker for the consumption of this food product. S-n-methylcysteine can be found primarily in blood and urine. S-Methyl-L-cysteine is a natural product that acts as a substrate in the catalytic antioxidant system mediated by methionine sulfoxide reductase A (MSRA), with antioxidative, neuroprotective, and anti-obesity activities.

   

S-N-Methylcysteine

S-methylcysteine, hydrochloride, (L-Cys)-isomer

C4H9NO2S (135.0354)


S-n-methylcysteine, also known as (2r)-2-amino-3-(methylsulfanyl)propanoic acid or 3-(methylthio)-L-alanine, is a member of the class of compounds known as L-cysteine-s-conjugates. L-cysteine-s-conjugates are compounds containing L-cysteine where the thio-group is conjugated. S-n-methylcysteine is soluble (in water) and a moderately acidic compound (based on its pKa). S-n-methylcysteine can be found in soft-necked garlic, which makes S-n-methylcysteine a potential biomarker for the consumption of this food product. S-n-methylcysteine can be found primarily in blood and urine. S-Methyl-L-cysteine is a natural product that acts as a substrate in the catalytic antioxidant system mediated by methionine sulfoxide reductase A (MSRA), with antioxidative, neuroprotective, and anti-obesity activities.

   

L-Cysteic acid

(2R)-2-Amino-3-sulphopropanoic acid

C3H7NO5S (169.0045)


Cysteinesulfonic acid, also known as (2r)-2-amino-3-sulfopropanoic acid or 3-sulfoalanine, 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. Cysteinesulfonic acid is soluble (in water) and an extremely strong acidic compound (based on its pKa). Cysteinesulfonic acid can be found in a number of food items such as roman camomile, pili nut, chicory, and garden tomato, which makes cysteinesulfonic acid a potential biomarker for the consumption of these food products.

   

2-Aminoethanesulfinic acid

2-Aminoethanesulfinic acid

C2H7NO2S (109.0197)


An aminosulfinic acid comprising ethylamine having the sulfo group at the 2-position. Hypotaurine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=300-84-5 (retrieved 2024-07-15) (CAS RN: 300-84-5). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Hypotaurine (2-aminoethanesulfinic acid), an intermediate in taurine biosynthesis from cysteine in astrocytes, is an endogenous inhibitory amino acid of the glycine receptor. Antioxidant[1].

   

L-Cysteinesulfinic acid

L-Cysteinesulfinic acid

C3H7NO4S (153.0096)


L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1]. L-Cysteinesulfinic acid is a potent agonist at several rat metabotropic glutamate receptors (mGluRs) with pEC50s of 3.92, 4.6, 3.9, 2.7, 4.0, and 3.94 for mGluR1, mGluR5, mGluR2, mGluR4, mGluR6, and mGluR8, respectively[1].

   

Taurine

Taurine

C2H7NO3S (125.0147)


Taurine, a sulphur-containing amino acid and an organic osmolyte involved in cell volume regulation, provides a substrate for the formation of bile salts, and plays a role in the modulation of intracellular free calcium concentration. Taurine has the ability to activate autophagy in adipocytes[1][2][3]. Taurine, a sulphur-containing amino acid and an organic osmolyte involved in cell volume regulation, provides a substrate for the formation of bile salts, and plays a role in the modulation of intracellular free calcium concentration. Taurine has the ability to activate autophagy in adipocytes[1][2][3].

   

β-alanine

beta-alanine

C3H7NO2 (89.0477)


A naturally-occurring beta-amino acid comprising propionic acid with the amino group in the 3-position. β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer. β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer. β-Alanine is a non-essential amino acid that is shown to be metabolized into carnosine, which functions as an intracellular buffer.

   

Cysteic Acid

dl-cysteic acid

C3H7NO5S (169.0045)


An amino sulfonic acid that is the sulfonic acid analogue of cysteine.

   

S-Methyl-L-cysteine

S-Methyl-L-cysteine

C4H9NO2S (135.0354)


S-Methyl-L-cysteine is a natural product that acts as a substrate in the catalytic antioxidant system mediated by methionine sulfoxide reductase A (MSRA), with antioxidative, neuroprotective, and anti-obesity activities.

   

furoic acid

L-Cysteic acid

C3H7NO5S (169.0045)


The L-enantiomer of cysteic acid.

   

(S)-1-Pyrroline-5-carboxylate

(S)-1-Pyrroline-5-carboxylate

C5H7NO2 (113.0477)