Classification Term: 2176
Cysteine and derivatives (ontology term: CHEMONTID:0004313)
Compounds containing cysteine or a derivative thereof resulting from reaction of cysteine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom." []
found 58 associated metabolites at no_class-level_7 metabolite taxonomy ontology rank level.
Ancestor: Alpha amino acids and derivatives
Child Taxonomies: L-cysteine-S-conjugates
L-Cysteine
Cysteine (Cys), also known as L-cysteine 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-alanine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Cysteine is found in all organisms ranging from bacteria to plants to animals. It is classified as an aliphatic, non-polar, sulfur-containing amino acid. Cysteine is an important source of sulfur in human metabolism, and although it is classified as a non-essential amino acid, cysteine may be essential for infants, the elderly, and individuals with certain metabolic disease or who suffer from malabsorption syndromes. Cysteine can occasionally be considered as an essential or conditionally essential amino acid. Cysteine is unique amongst the twenty natural amino acids as it contains a thiol group. Thiol groups can undergo oxidation/reduction (redox) reactions; when cysteine is oxidized it can form cystine, which is two cysteine residues joined by a disulfide bond. This reaction is reversible since the reduction of this disulphide bond regenerates two cysteine molecules. The disulphide bonds of cystine are crucial to defining the structures of many proteins. Cysteine is often involved in electron-transfer reactions, and help the enzyme catalyze its reaction. Cysteine is also part of the antioxidant glutathione. N-Acetyl-L-cysteine (NAC) is a form of cysteine where an acetyl group is attached to cysteines nitrogen atom and is sold as a dietary supplement. Cysteine is named after cystine, which comes from the Greek word kustis meaning bladder (cystine was first isolated from kidney stones). Oxidation of cysteine can produce a disulfide bond with another thiol and further oxidation can produce sulphfinic or sulfonic acids. The cysteine thiol group is also a nucleophile and can undergo addition and substitution reactions. Thiol groups become much more reactive when they are ionized, and cysteine residues in proteins have pKa values close to neutrality, so they are often in their reactive thiolate form in the cell. The thiol group also has a high affinity for heavy metals and proteins containing cysteine will bind metals such as mercury, lead, and cadmium tightly. Due to this ability to undergo redox reactions, cysteine has antioxidant properties. Cysteine is important in energy metabolism. As cystine, it is a structural component of many tissues and hormones. Cysteine has clinical uses ranging from treating baldness to psoriasis to preventing smokers hack. In some cases, oral cysteine therapy has proved excellent for treatment of asthmatics, enabling them to stop theophylline and other medications. Cysteine also enhances the effect of topically applied silver, tin, and zinc salts in preventing dental cavities. In the future, cysteine may play a role in the treatment of cobalt toxicity, diabetes, psychosis, cancer, and seizures (http://www.dcnutrition.com/AminoAcids/). Cysteine has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). [Spectral] L-Cysteine (exact mass = 121.01975) and D-2-Aminobutyrate (exact mass = 103.06333) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] L-Cysteine (exact mass = 121.01975) and Creatine (exact mass = 131.06948) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Detoxicant, dietary supplement, dough strengthener, yeast nutrient for leavened bakery products. Flavouring agent. Enzymic browning inhibitor. L-Cysteine is found in many foods, some of which are bilberry, mugwort, cowpea, and sweet bay. L-(+)-Cysteine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=52-90-4 (retrieved 2024-07-01) (CAS RN: 52-90-4). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Cysteine is a conditionally essential amino acid, which acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), glutathione and taurine. L-Cysteine suppresses ghrelin and reduces appetite in rodents and humans[1]. L-Cysteine is a conditionally essential amino acid, which acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), glutathione and taurine. L-Cysteine suppresses ghrelin and reduces appetite in rodents and humans[1].
S-Carboxymethyl-L-cysteine
S-carboxymethylcysteine (carbocisteine) is the most frequently prescribed mucoactive agent for long-term COPD (chronic obstructive pulmonary disease) use in a number of countries. In addition to its mucoregulatory activity, carbocisteine exhibits free-radical scavenging and anti-inflammatory properties. S-Carboxymethyl-L-cysteine can be found in root vegetables and has been isolated from radish seedlings. S-carboxymethyl-L-cysteine can be detectable in urine especially after the processing of chlorinated compounds by gut microlfora. R - Respiratory system > R05 - Cough and cold preparations > R05C - Expectorants, excl. combinations with cough suppressants > R05CB - Mucolytics Acquisition and generation of the data is financially supported in part by CREST/JST. C78273 - Agent Affecting Respiratory System > C74536 - Mucolytic Agent D019141 - Respiratory System Agents > D005100 - Expectorants D000890 - Anti-Infective Agents KEIO_ID A059
Thiocysteine
The reactive species in the phosphofructokinase modulation system could be considered thiocysteine (R-S-S-) or cystine trisulfide (R-S-S-S-R) produced from cystine in the presence of gamma-Cystathionase (CST, EC 4.4.1.1). The desulfuration reaction of cystine in vivo produces thiocysteine containing a bound sulfur atom. Persulfide generated from L-cysteine inactivates tyrosine aminotransferase. Thiocysteine is the reactive (unstable) intermediate of thiocystine which functions as a persulfide in transferring its sulfane sulfur to thiophilic acceptors. Thiocystine conversion to unstable thiocysteine is accelerated by sulfhydryl compounds, or reagents that cleave sulfur-sulfur bonds to yield sulfhydryl groups. Thiocystine is proposed as the storage form of sulfane sulfur in biological systems. Liver cytosols contain factors that produce an inhibitor of tyrosine aminotransferase in 3 steps: initial oxidation of cysteine to form cystine; desulfurization of cystine catalyzed by cystathionase to form the persulfide, thiocysteine; and reaction of thiocysteine (or products of its decomposition) with proteins to form protein-bound sulfane. (PMID: 2903161, 454618, 7287665) [HMDB] The reactive species in the phosphofructokinase modulation system could be considered thiocysteine (R-S-S-) or cystine trisulfide (R-S-S-S-R) produced from cystine in the presence of gamma-Cystathionase (CST, EC 4.4.1.1). The desulfuration reaction of cystine in vivo produces thiocysteine containing a bound sulfur atom. Persulfide generated from L-cysteine inactivates tyrosine aminotransferase. Thiocysteine is the reactive (unstable) intermediate of thiocystine which functions as a persulfide in transferring its sulfane sulfur to thiophilic acceptors. Thiocystine conversion to unstable thiocysteine is accelerated by sulfhydryl compounds, or reagents that cleave sulfur-sulfur bonds to yield sulfhydryl groups. Thiocystine is proposed as the storage form of sulfane sulfur in biological systems. Liver cytosols contain factors that produce an inhibitor of tyrosine aminotransferase in 3 steps: initial oxidation of cysteine to form cystine; desulfurization of cystine catalyzed by cystathionase to form the persulfide, thiocysteine; and reaction of thiocysteine (or products of its decomposition) with proteins to form protein-bound sulfane. (PMID: 2903161, 454618, 7287665).
S-Allylcysteine
Occurs in garlic. Potential nutriceutical. S-Allylcysteine is found in garden onion, soft-necked garlic, and onion-family vegetables. S-Allylcysteine is found in garden onion. S-Allylcysteine occurs in garlic. Potential nutriceutica D000970 - Antineoplastic Agents S-Allyl-L-cysteine, one of the organosulfur compounds found in AGE, possess various biological effects including neurotrophic activity, anti-cancer activity, anti-inflammatory activity. S-Allyl-L-cysteine, one of the organosulfur compounds found in AGE, possess various biological effects including neurotrophic activity, anti-cancer activity, anti-inflammatory activity.
D-Cysteine
D-cysteine is an optically active form of cysteine having D-configuration. It is a cysteine and a D-alpha-amino acid. It is a conjugate base of a D-cysteinium. It is a conjugate acid of a D-cysteinate(1-). It is an enantiomer of a L-cysteine. It is a tautomer of a D-cysteine zwitterion. D-Cysteine, also known as D-cystein or DCY, belongs to the class of organic compounds known as cysteine and derivatives. Cysteine and derivatives are compounds containing cysteine or a derivative thereof resulting from reaction of cysteine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. It is a non-proteogenic sulfur-containing amino acid. D-Cysteine is known to be toxic to bacteria and several bacteria (and plants) have developed and enzyme called D-cysteine desulfhydrase (EC4.1.99.4). D-cysteine can be generated from D-Cysteine via cysteine racemase. D-Cysteine is a naturally occurring enantiomer of L-Cysteine. Cysteine is named after cystine, which comes from the Greek word kustis meaning bladder -cystine was first isolated from kidney stones. D-Cysteine exists in all living species, ranging from bacteria to humans. Outside of the human body, D-Cysteine has been detected, but not quantified in several different foods, such as chervils, fruits, lichee, nuts, and cherimoya. Cysteine (abbreviated as Cys or C) is an alpha-amino acid. The L-isomer is one of the 22 proteinogenic amino acids, i.e., the building blocks of proteins. D-isomers are used as carbon, nitrogen, and energy source. Cysteine is unique among the twenty common amino acids because it contains a thiol group. [YMDB]. D-Cysteine is found in many foods, some of which are red raspberry, muscadine grape, pigeon pea, and groundcherry. D-Cysteine is the D-isomer of cysteine and a powerful inhibitor of Escherichia coli growth. D-cysteine is mediated by D-amino acid oxidase to produce H2S and is a neuroprotectant against cerebellar ataxias. D-Cysteine could inhibit the growth and cariogenic virulence of dual-species biofilms formed by S. mutans and S. sanguinis[1][2][3].
Cystine
Flavouring ingredient. (±)-Cystine is found in many foods, some of which are green bell pepper, green zucchini, italian sweet red pepper, and red bell pepper.
S-methylcysteine
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.
trans-S-(1-Propenyl)-L-cysteine
trans-S-(1-Propenyl)-L-cysteine is found in onion-family vegetables. trans-S-(1-Propenyl)-L-cysteine is a constituent of garlic
S-(Allylthio)-L-cysteine
S-(Allylthio)-L-cysteine is found in onion-family vegetables. S-(Allylthio)-L-cysteine is isolated from garlic (Allium sativum). Potential nutriceutical. Isolated from garlic (Allium sativum). Potential nutriceutical. S-(Allylthio)-L-cysteine is found in garlic and onion-family vegetables.
(2R,2'S)-Isobuteine
(2R,2S)-Isobuteine is found in onion-family vegetables. (2R,2S)-Isobuteine occurs naturally as a component of the tripeptide S-(2-carboxypropyl)glutathione in onion and in garli
S-Cysteinosuccinic acid
S-Cysteinosuccinic acid is found in pulses. S-Cysteinosuccinic acid is isolated from seeds of Vigna radiata (mung bean
18-Carboxy-dinor-LTE4
18-carboxy-dinor-LTE4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078). Leukotrienes are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. 18-carboxy-dinor-LTE4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078)
S-Propyl-L-cysteine
S-Propyl-L-cysteine is found in onion-family vegetables. S-Propyl-L-cysteine is occurs as g-glutamyl peptide in garli Occurs as g-glutamyl peptide in garlic. S-Propyl-L-cysteine is found in onion-family vegetables.
Allocystathionine
Allocystathionine belongs to the class of organic compounds known as cysteines and cysteine derivatives. Cysteine and cysteine derivatives are compounds containing cysteine or a derivative thereof resulting from the reaction of cysteine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Allocystathionine is a stereo-isomer of cystathionine. Both cystathionine and allocystathionine are modified amino acids generated by enzymic means from homocysteine and serine. Allocystathionine is a product of enzyme cystathionine synthetase (EC 2.5.1.48) which converts homocysteine into allocystathionine in the sulfur metabolism pathway. It is also the substrate of enzyme cystathionine beta-lyase (EC 4.4.1.8) in the same pathway (KEGG). Cystathionine and allocystathionine can be used by the enzymes cystathionine gamma-lyase (CTH), cysteine dioxygenase (CDO), and sulfinoalanine decarboxylase to produce hypotaurine and then taurine. Allocystathionine is a product of enzyme cystathionine synthetase [EC 2.5.1.48] which converts homocysteine to allocystathionine in the sulfur metabolism pathway. It is also the substrate of enzyme cystathionine beta-lyase [4.4.1.8] in the same pathway. (KEGG) [HMDB]
Hawkinsin
Hawkinsin is a sulfur amino acid identified as (2-L-cystein-S-yl-1,4-dihydroxycyclohex-5-en-1-yl)acetic acid. It is a reactive byproduct of abnormal tyrosine metabolism. Normally, the breakdown of the amino acid tyrosine involves the conversion of 4-hydroxyphenylpyruvate to homogentisate by 4-hydroxyphenylpyruvate dioxygenase. Complete deficiency of this enzyme leads to an inborn error of metabolism called tyrosinemia III. In rare cases, however, the enzyme is still able to produce the reactive intermediate 1,2-epoxyphenyl acetic acid but is unable to convert this intermediate to homogentisate (PMID: 11073718). The intermediate then spontaneously reacts with glutathione to form hawkinsin. Chronically high levels of hawkinsin are associated with hawkinsinuria (characterized by the inability to break down the amino acid tyrosine). Patients with hawkinsinuria excrete hawkinsin in their urine throughout their life. The features of this condition usually appear around the time infants are weaned off breast milk and begin to use formula. The signs and symptoms may include the following: failure to gain weight and grow at the expected rate (failure to thrive), abnormally high acid levels in the blood (acidosis), and fine or sparse hair. Hawkinsin is 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. Hawkinsin 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 untreated hawkinsinuria. 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. Hawkinsin is a sulfur amino acid identified as (2-l-cystein-S-yl, 4-dihydroxycyclohex-5-en-1-yl)acetic acid. Patients with hawkinsinuria excrete this metabolite in their urine throughout their life, although symptoms of metabolic acidosis and tyrosinemia improve in the first year of life. Alterations in the structure and activity of 4-hydroxyphenylpyruvic acid dioxygenase are causally related to two different metabolic disorders, tyrosinemia type III and hawkinsinuria. (PMID 11073718) [HMDB]
S-Prenyl-L-cysteine
S-Prenyl-L-cysteine is catalysed by prenylcysteine oxidase to form L-cysteine.A flavoprotein (FAD). Cleaves the thioether bond of S-prenyl-L-cysteines, such as S-farnesylcysteine and S-geranylgeranylcysteine. N-Acetyl-prenylcysteine and. prenylcysteinyl peptides are not substrates. This reaction may represent the final. step in the degradation of prenylated proteins in mammalian tissues. The enzyme is originally thought to be a simple lyase so it had been classified as. EC 4.4.1.18. S-Prenyl-L-cysteine is catalysed by prenylcysteine oxidase to form L-cysteine.A flavoprotein (FAD). Cleaves the thioether bond of S-prenyl-L-cysteines, such as S-farnesylcysteine and S-geranylgeranylcysteine. N-Acetyl-prenylcysteine and
13E-Tetranor-16-carboxy-LTE4
13E-tetranor-16-carboxy-LTE4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078). Leukotrienes are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. 13E-tetranor-16-carboxy-LTE4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078)
20-COOH-leukotriene E4
20-COOH-leukotriene E4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078). Leukotrienes are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. 20-COOH-leukotriene E4 is a metabolite through lipid oxidation of Leukotriene E4 (LTE4).Leukotriene E4 (LTE4) is a cysteinyl leukotriene. Cysteinyl leukotrienes (CysLTs) are a family of potent inflammatory mediators that appear to contribute to the pathophysiologic features of allergic rhinitis. Nasal blockage induced by CysLTs is mainly due to dilatation of nasal blood vessels, which can be induced by the nitric oxide produced through CysLT1 receptor activation. LTE4, activate contractile and inflammatory processes via specific interaction with putative seven transmembrane-spanning receptors that couple to G proteins and subsequent intracellular signaling pathways. LTE4 is metabolized from leukotriene C4 in a reaction catalyzed by gamma-glutamyl transpeptidase and a particulate dipeptidase from kidney. (PMID: 12607939, 12432945, 6311078)
S-(2-Aminoethyl)-L-cysteine
S-(2-Aminoethyl)-L-cysteine is found in mushrooms. S-(2-Aminoethyl)-L-cysteine is isolated from the edible mushroom Rozites caperta. Isolated from the edible mushroom Rozites caperta. S-(2-Aminoethyl)-L-cysteine is found in mushrooms.
Ajocysteine
Ajocysteine is found in onion-family vegetables. Ajocysteine is a constituent of garlic (Allium sativum). Constituent of garlic (Allium sativum). Ajocysteine is found in garlic and onion-family vegetables.
S-(5-Acetamido-2-hydroxyphenyl)cysteine
(2R)-2-Amino-3-(1,2-dichloroethenylsulfanyl)propanoic acid
2-(4-(((2-Amino-4-oxo-3,4,7,8-tetrahydropteridin-6-yl)methyl)amino)benzamido)pentanedioic acid
2-Amino-4-[(2-amino-2-carboxyethyl)disulfanyl]butanoic acid
Djenkolic acid
Djenkolic acid is a sulfur-containing non-protein amino acid naturally found in the djenkol beans of the Southeast Asian plant Archidendron jiringa. Djenkolic Acid often causes renal injury, including hypersensitivity to or a direct toxic effect of a djenkol bean metabolite, resulting in acute kidney injury and/or urinary tract obstruction by djenkolic acid crystals, sludge, and/or possible ureteral spasms[1].
2,3-Dipalmitoyl-S-glycerylcysteine
Pegdinetanib
Methylcysteine sulfoxide
Methylcysteine sulfoxide is practically insoluble (in water) and an extremely weak basic (essentially neutral) compound (based on its pKa). Methylcysteine sulfoxide can be found in soft-necked garlic, which makes methylcysteine sulfoxide a potential biomarker for the consumption of this food product.
Cystathione
Cystathione, also known as dl-cystathionine, belongs to cysteine and derivatives class of compounds. Those are compounds containing cysteine or a derivative thereof resulting from reaction of cysteine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Cystathione is soluble (in water) and a moderately acidic compound (based on its pKa). Cystathione can be found in corn, which makes cystathione a potential biomarker for the consumption of this food product. Cystathione may be a unique E.coli metabolite.
Cysteine hydrochloride
Dietary supplement, nutrient. Dough conditioner. Cysteine (abbreviated as Cys or C) is an ?-amino acid with the chemical formula HO2CCH(NH2)CH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is nonpolar and thus cysteine is usually classified as a hydrophobic amino acid. The thiol side chain often participates in enzymatic reactions, serving as a nucleophile. The thiol is susceptible to oxidization to give the disulfide derivative cystine, which serves an important structural role in many proteins. Cysteine is named after cystine.; Cysteine is a very popular target for site-directed labeling experiments to investigate biomolecular structure and dynamics. Maleimides will selectively attach to cysteine using a covalent Michael addition. Site-directed spin labeling for EPR or paramagnetic relaxation enhanced NMR also uses cysteine extensively.; Cysteine is an important source of sulfide in human metabolism. The sulfide in iron-sulfur clusters and in nitrogenase is extracted from cysteine, which is converted to alanine in the process.; Cysteine is required by sheep in order to produce wool: it is an essential amino acid which must be taken in as food from grass. As a consequence, during drought conditions, sheep stop producing wool; however, transgenic sheep which can make their own cysteine have been developed.[citation needed]; Cysteine, mainly the L-enantiomer, is a precursor in the food, pharmaceutical, and personal care industries. One of the largest applications is the production of flavors. For example, the reaction of cysteine with sugars in a Maillard reaction yields meat flavors. L-cysteine is also used as a processing aid for baking. Small quantities (in the tens of ppm range) help to soften the dough and thus reduce processing time. http://www.cfsan.fda.gov/~dms/foodic.html; High levels of Cysteine, due to its reducing capacity, have been shown to inactivate insulin under certain conditions. This is because insulin contains three disulfide bonds, one of which can be reduced by cysteine. If this happens, insulin looses its characteristic structure and thus looses functionality. During a hypoglycemia attack (where there is too much insulin in the blood causing an unsafe drop in blood sugar) Cysteine can be used to inactivate insulin, allowing blood sugar levels to normalize. In some cases, the use of Thiamine, vitamin C, and Cysteine have been successful in treating severe cases of hypoglycemia. Additionally, due to its interaction with insulin, diabetics should avoid supplements or medications that contain cysteine or have the potential to increase cysteine levels.; In a 1994 report released by five top cigarette companies, cysteine is one of the 599 additives to cigarettes. Like most cigarette additives, however, its use or purpose is unknown. Its inclusion in cigarettes could offer two benefits: Acting as an expectorant, since smoking increases mucus production in the lungs; and increasing the beneficial antioxidant glutathione (which is diminished in smokers).; N-acetyl-L-cysteine (NAC) is a derivative of cysteine wherein an acetyl group is attached to the nitrogen atom. This compound is sometimes considered as a dietary supplement, although it is not an ideal source since it is catabolized in the gut.[citation needed] NAC is often used as a cough medicine because it breaks up the disulfide bonds in the mucus and thus liquefies it, making it easier to cough up. It is also this action of breaking disulfide bonds that makes it useful in thinning the abnormally thick mucus in Cystic Fibrosis patients. NAC is also used as a specific antidote in cases of acetaminophen overdose.; Oxidation of cysteine produces the disulfide cystine. More aggressive oxidants convert cysteine to the corresponding sulfinic acid and sulfonic acid. Cysteine residues play a valuable role by crosslinking proteins, which increases the prot... Dietary supplement, nutrient. Dough conditioner
4-hydroxy-2-nonenal-[L-Cys] conjugate
4-hydroxy-2-nonenal-[l-cys] conjugate is practically insoluble (in water) and a moderately acidic compound (based on its pKa). 4-hydroxy-2-nonenal-[l-cys] conjugate can be found in a number of food items such as ginkgo nuts, sweet orange, taro, and black crowberry, which makes 4-hydroxy-2-nonenal-[l-cys] conjugate a potential biomarker for the consumption of these food products.
