Exact Mass: 441.18008080000004

Exact Mass Matches: 441.18008080000004

Found 463 metabolites which its exact mass value is equals to given mass value 441.18008080000004, within given mass tolerance error 0.05 dalton. Try search metabolite list with more accurate mass tolerance error 0.01 dalton.

Folic acid

FOLVITE(Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1422)

C19H19N7O6 (441.1396754)

Folic acid appears as odorless orange-yellow needles or platelets. Darkens and chars from approximately 482 °F. Folic acid is an N-acyl-amino acid that is a form of the water-soluble vitamin B9. Its biologically active forms (tetrahydrofolate and others) are essential for nucleotide biosynthesis and homocysteine remethylation. It has a role as a human metabolite, a nutrient and a mouse metabolite. It is a member of folic acids and a N-acyl-amino acid. It is functionally related to a pteroic acid. It is a conjugate acid of a folate(2-). Folic acid, also known as folate or Vitamin B9, is a member of the B vitamin family and an essential cofactor for enzymes involved in DNA and RNA synthesis. More specifically, folic acid is required by the body for the synthesis of purines, pyrimidines, and methionine before incorporation into DNA or protein. Folic acid is particularly important during phases of rapid cell division, such as infancy, pregnancy, and erythropoiesis, and plays a protective factor in the development of cancer. As humans are unable to synthesize folic acid endogenously, diet and supplementation is necessary to prevent deficiencies. For example, folic acid is present in green vegetables, beans, avocado, and some fruits. In order to function within the body, folic acid must first be reduced by the enzyme dihydrofolate reductase (DHFR) into the cofactors dihydrofolate (DHF) and tetrahydrofolate (THF). This important pathway, which is required for de novo synthesis of nucleic acids and amino acids, is disrupted by anti-metabolite therapies such as [DB00563] as they function as DHFR inhibitors to prevent DNA synthesis in rapidly dividing cells, and therefore prevent the formation of DHF and THF. When used in high doses such as for cancer therapy, or in low doses such as for Rheumatoid Arthritis or psoriasis, [DB00563] impedes the bodys ability to create folic acid. This results in a deficiency of coenzymes and a resultant buildup of toxic substances that are responsible for numerous adverse side effects. As a result, supplementation with 1-5mg of folic acid is recommended to prevent deficiency and a number of side effects associated with MTX therapy including mouth ulcers and gastrointestinal irritation. [DB00650] (also known as folinic acid) supplementation is typically used for high-dose MTX regimens for the treatment of cancer. Levoleucovorin and leucovorin are analogs of tetrahydrofolate (THF) and are able to bypass DHFR reduction to act as a cellular replacement for the co-factor THF. There are also several antiepileptic drugs (AEDs) that are associated with reduced serum and red blood cell folate, including [DB00564] (CBZ), [DB00252] (PHT), or barbiturates. Folic acid is therefore often provided as supplementation to individuals using these medications, particularly to women of child-bearing age. Inadequate folate levels can result in a number of health concerns including cardiovascular disease, megaloblastic anemias, cognitive deficiencies, and neural tube defects (NTDs). Folic acid is typically supplemented during pregnancy to prevent the development of NTDs and in individuals with alcoholism to prevent the development of neurological disorders, for example. Folic acid is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). CID 6037 is a natural product found in Beta vulgaris, Angelica sinensis, and other organisms with data available. Folic Acid is a collective term for pteroylglutamic acids and their oligoglutamic acid conjugates. As a natural water-soluble substance, folic acid is involved in carbon transfer reactions of amino acid metabolism, in addition to purine and pyrimidine synthesis, and is essential for hematopoiesis and red blood cell production. (NCI05) A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treat... Folic acid or folate, is a vitamin that belongs to the class of compounds known as pterins. Chemically, folate consists of three distinct chemical moieties linked together. A pterin (2-amino-4-hydroxy-pteridine) linked by a methylene bridge to a p-aminobenzoyl group that in turn is linked through an amide linkage to glutamic acid. It is a member of the vitamin B family and is primarily known as vitamin B9. Folate is required for the body to make DNA and RNA and metabolize amino acids necessary for cell division for the hematopoietic system. As humans cannot make folate, it is required in the diet, making it an essential nutrient (i.e. a vitamin). Folate occurs naturally in many foods including mushrooms, spinach, yeast, green leaves, and grasses (poaceae). Folic acid, being biochemically inactive, is converted to tetrahydrofolic acid and methyltetrahydrofolate by the enzyme known as dihydrofolate reductase. Tetrahydrofolate and methyltetrahydrofolate are transported across cells by receptor-mediated endocytosis where they are needed to maintain normal erythropoiesis, synthesize purine and thymidylate nucleic acids, interconvert amino acids and generate formic acid. Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in babies. Low levels in early pregnancy are believed to be the cause of more than half of babies born with NTDs (PMID: 28097362). Folic acid is also a microbial metabolite produced by Bifidobacterium and Lactobacillus (PMID: 22254078). An N-acyl-amino acid that is a form of the water-soluble vitamin B9. Its biologically active forms (tetrahydrofolate and others) are essential for nucleotide biosynthesis and homocysteine remethylation. B - Blood and blood forming organs > B03 - Antianemic preparations > B03B - Vitamin b12 and folic acid > B03BB - Folic acid and derivatives COVID info from clinicaltrial, clinicaltrials, clinical trial, clinical trials D006401 - Hematologic Agents > D006397 - Hematinics D018977 - Micronutrients > D014815 - Vitamins V - Various > V04 - Diagnostic agents Dietary supplement Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS Formula(Parent): C19H19N7O6; Bottle Name:Folic acid ,approx; PRIME Parent Name:Folic acid; PRIME in-house No.:V0080; SubCategory_DNP: Pteridines and analogues, Pteridine alkaloids Acquisition and generation of the data is financially supported in part by CREST/JST. relative retention time with respect to 9-anthracene Carboxylic Acid is 0.543 CONFIDENCE standard compound; INTERNAL_ID 134 Folic acid (Vitamin B9) is a orally active essential nutrient from the B complex group of vitamins. Folic acid shows antidepressant-like effect. Folic acid sodium reduces the risk of neonatal neural tube defects. Folic acid can be used to the research of megaloblastic and macrocytic anemias due to folic deficiency[1][2][3][4]. Folic acid (Vitamin B9) is a orally active essential nutrient from the B complex group of vitamins. Folic acid shows antidepressant-like effect. Folic acid sodium reduces the risk of neonatal neural tube defects. Folic acid can be used to the research of megaloblastic and macrocytic anemias due to folic deficiency[1][2][3][4].

Dofetilide

N-[4-(2-{[2-(4-methanesulfonamidophenyl)ethyl](methyl)amino}ethoxy)phenyl]methanesulfonamide

C19H27N3O5S2 (441.1392052)

Dofetilide is a class III antiarrhythmic agent that is approved by the Food and Drug Administration (FDA) for the maintenance of sinus rhythm in individuals prone to the formation of atrial fibrillation and flutter, and for the chemical cardioversion to sinus rhythm from atrial fibrillation and flutter. [Wikipedia] C - Cardiovascular system > C01 - Cardiac therapy > C01B - Antiarrhythmics, class i and iii > C01BD - Antiarrhythmics, class iii C78274 - Agent Affecting Cardiovascular System > C47793 - Antiarrhythmic Agent D002317 - Cardiovascular Agents > D026902 - Potassium Channel Blockers D002317 - Cardiovascular Agents > D000889 - Anti-Arrhythmia Agents D049990 - Membrane Transport Modulators C93038 - Cation Channel Blocker

platencimycin

C24H27NO7 (441.17874320000004)

D000963 - Antimetabolites > D000960 - Hypolipidemic Agents > D054872 - Fatty Acid Synthesis Inhibitors D057847 - Lipid Regulating Agents > D000960 - Hypolipidemic Agents D009676 - Noxae > D000963 - Antimetabolites D000890 - Anti-Infective Agents

Imidapril hydrochloride

Imidapril (hydrochloride)

C20H28ClN3O6 (441.16665380000006)

D004791 - Enzyme Inhibitors > D011480 - Protease Inhibitors > D000806 - Angiotensin-Converting Enzyme Inhibitors C78274 - Agent Affecting Cardiovascular System > C270 - Antihypertensive Agent C471 - Enzyme Inhibitor > C783 - Protease Inhibitor > C247 - ACE Inhibitor D002317 - Cardiovascular Agents > D000959 - Antihypertensive Agents

Nebivolol HCl

rac Nebivolol hydrochloride

C22H26ClF2NO4 (441.1518330000001)

D018377 - Neurotransmitter Agents > D018663 - Adrenergic Agents > D000322 - Adrenergic Agonists D002317 - Cardiovascular Agents > D000959 - Antihypertensive Agents D002317 - Cardiovascular Agents > D014665 - Vasodilator Agents Nebivolol (R 065824) hydrochloride is an orally active beta receptor blocker and has the high beta(1)-receptor affinity.Nebivolol hydrochloride has direct vasodilator properties and adrenergic blocking characteristics. Nebivolol hydrochloride can be used for the research of kinds of diseases such as hypertension, coronary artery disease, congestive heart failure and ischemic heart disease[1][2].

troglitazone

5-[[4-[(3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)methoxy]phenyl]methyl]-2,4-thiazlidinedione

C24H27NO5S (441.1609852000001)

A - Alimentary tract and metabolism > A10 - Drugs used in diabetes > A10B - Blood glucose lowering drugs, excl. insulins > A10BG - Thiazolidinediones C78276 - Agent Affecting Digestive System or Metabolism > C29711 - Anti-diabetic Agent > C98241 - Thiazolidinedione Antidiabetic Agent C274 - Antineoplastic Agent > C2122 - Cell Differentiating Agent > C1934 - Differentiation Inducer D007004 - Hypoglycemic Agents CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5234; ORIGINAL_PRECURSOR_SCAN_NO 5232 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5241; ORIGINAL_PRECURSOR_SCAN_NO 5238 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5206; ORIGINAL_PRECURSOR_SCAN_NO 5205 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5244; ORIGINAL_PRECURSOR_SCAN_NO 5241 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5240; ORIGINAL_PRECURSOR_SCAN_NO 5238 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 5233; ORIGINAL_PRECURSOR_SCAN_NO 5232 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 9800; ORIGINAL_PRECURSOR_SCAN_NO 9795 CONFIDENCE standard compound; INTERNAL_ID 701; DATASET 20200303_ENTACT_RP_MIX506; DATA_PROCESSING MERGING RMBmix ver. 0.2.7; DATA_PROCESSING PRESCREENING Shinyscreen ver. 0.8.0; ORIGINAL_ACQUISITION_NO 9806; ORIGINAL_PRECURSOR_SCAN_NO 9803 Troglitazone is an orally active PPARγ agonist, with EC50s of 550 nM and 780 nM for human and murine?PPARγ receptor, respectively. Troglitazone has anticancer activity, prevents and inhibits the development of type 2 diabetes.

Mandelonitrile rutinoside

2-phenyl-2-[(3,4,5-trihydroxy-6-{[(3,4,5-trihydroxy-6-methyloxan-2-yl)oxy]methyl}oxan-2-yl)oxy]acetonitrile

C20H27NO10 (441.1634882000001)

Mandelonitrile rutinoside is found in fruits. Mandelonitrile rutinoside is a constituent of the fruit of purple passion fruit (Passiflora edulis). Constituent of the fruit of purple passion fruit (Passiflora edulis). Mandelonitrile rutinoside is found in fruits.

18-Carboxy-dinor-LTE4

(4Z,7Z,9E,11E,13R,14S)-13-{[(2S)-2-amino-2-carboxyethyl]sulfanyl}-14-hydroxyoctadeca-4,7,9,11-tetraenedioic acid

C21H31NO7S (441.18211360000004)

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)

Vilazodone

2-Benzofurancarboxamide, 5-(4-(4-(5-cyano-1H-indol-3-yl)butyl)-1-piperazinyl)-, hydrochloride (1:1)

C26H27N5O2 (441.2164642)

Vilazodone is a novel compound with combined high affinity and selectivity for the 5-hydroxytryptamine (5-HT) transporter and 5-HT(1A) receptors. It has been shown to be equally efficacious as other antidepressants with similar gastrointestinal side effects and possibly with reduced sexual side effects and weight gain. Vilazodone is an antidepressant agent that can used as an alternative for patients who cannot tolerate therapy with other antidepressant classes such as selective serotonin reuptake inhibitors or serotonin norepinephrine reuptake inhibitors. Treatment should be titrated towards the target dose, which is 40mg per day. D018377 - Neurotransmitter Agents > D018490 - Serotonin Agents > D017367 - Selective Serotonin Reuptake Inhibitors D002491 - Central Nervous System Agents > D011619 - Psychotropic Drugs > D000928 - Antidepressive Agents D018377 - Neurotransmitter Agents > D018490 - Serotonin Agents > D017366 - Serotonin Receptor Agonists D018377 - Neurotransmitter Agents > D014179 - Neurotransmitter Uptake Inhibitors C78272 - Agent Affecting Nervous System > C265 - Antidepressant Agent N - Nervous system > N06 - Psychoanaleptics > N06A - Antidepressants D049990 - Membrane Transport Modulators Vilazodone (EMD 68843; SB 659746A) is a potent, selective and orally active?serotonin?reuptake inhibitor (SSRI) and partial?5-HT1A receptor agonist. Vilazodone exhibits antidepressant efficacy in vivo can be used for the research of major depressive disorder (MDD) and affective disorders[1][2].

3-N-(2-Fluoroethyl)spiperone

3-(2-fluoroethyl)-8-[4-(4-fluorophenyl)-4-oxobutyl]-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one

C25H29F2N3O2 (441.22277180000003)

D019995 - Laboratory Chemicals > D007202 - Indicators and Reagents > D019275 - Radiopharmaceuticals

Folcidin

2-[(4-{[(4-hydroxy-2-imino-1,2-dihydropteridin-6-yl)methyl]amino}phenyl)formamido]pentanedioate

C19H19N7O6 (441.1396754)

Bacmecillinam

1-[(ethoxycarbonyl)oxy]ethyl 6-{[(azepan-1-yl)methylidene]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate

C20H31N3O6S (441.19334660000004)

6H-Dipyrido[3,2-b:2',3'-e][1,4]diazepin-6-one, 11-ethyl-5,11-dihydro-5-methyl-8-[2-[(1-oxido-4-quinolinyl)oxy]ethyl]-

4-(2-{2-ethyl-9-methyl-10-oxo-2,4,9,15-tetraazatricyclo[9.4.0.0^{3,8}]pentadeca-1(15),3(8),4,6,11,13-hexaen-13-yl}ethoxy)quinolin-1-ium-1-olate

C25H23N5O3 (441.18008080000004)

Brivanib alaninate

1-({4-[(4-fluoro-2-methyl-1H-indol-5-yl)oxy]-5-methylpyrrolo[2,1-F][1,2,4]triazin-6-yl}oxy)propan-2-yl 2-aminopropanoic acid

C22H24FN5O4 (441.1812236)

Db-cAMP

6-[6-(dibutylamino)purin-9-yl]-2-hydroxy-2-oxo-4a,6,7,7a-tetrahydro-4H-furo[3,2-d][1,3,2]dioxaphosphinin-7-ol

C18H28N5O6P (441.17771180000005)

Deflazacort

2-{11-hydroxy-6,9,13-trimethyl-16-oxo-5-oxa-7-azapentacyclo[10.8.0.0^{2,9}.0^{4,8}.0^{13,18}]icosa-6,14,17-trien-8-yl}-2-oxoethyl acetate

C25H31NO6 (441.2151266)

4-(2-((4-(2-(Pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl)quinolin-7-yl)oxy)ethyl)morpholine

C26H27N5O2 (441.2164642)

troglitazone

5-({4-[(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-1-benzopyran-2-yl)methoxy]phenyl}methyl)-1,3-thiazolidine-2,4-dione

C24H27NO5S (441.1609852000001)

4-Hydroxy-5-[[4-[[(2R)-6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydrochromen-2-yl]methoxy]phenyl]methyl]-3H-1,3-thiazol-2-one

4-hydroxy-5-({4-[(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-1-benzopyran-2-yl)methoxy]phenyl}methyl)-2,3-dihydro-1,3-thiazol-2-one

C24H27NO5S (441.1609852000001)

7,8-dihydrofolate

4-Carboxy-4-[(4-{[(2-imino-4-oxido-1,2,7,8-tetrahydropteridin-6-yl)methyl]amino}phenyl)formamido]butanoic acid

C19H19N7O6 (441.1396754)

7,8-dihydrofolate is practically insoluble (in water) and a weakly acidic compound (based on its pKa). 7,8-dihydrofolate can be found in a number of food items such as pineapple, common verbena, pear, and citrus, which makes 7,8-dihydrofolate a potential biomarker for the consumption of these food products.

Alpelisib

(2S)-N1-{4-methyl-5-[2-(1,1,1-trifluoro-2-methylpropan-2-yl)pyridin-4-yl]-1,3-thiazol-2-yl}pyrrolidine-1,2-dicarboximidic acid

C19H22F3N5O2S (441.14462280000004)

L - Antineoplastic and immunomodulating agents > L01 - Antineoplastic agents > L01E - Protein kinase inhibitors > L01EM - Phosphatidylinositol-3-kinase (pi3k) inhibitors C274 - Antineoplastic Agent > C163758 - Targeted Therapy Agent > C2152 - Phosphatidylinositide 3-Kinase Inhibitor C274 - Antineoplastic Agent > C2189 - Signal Transduction Inhibitor > C129824 - Antineoplastic Protein Inhibitor C471 - Enzyme Inhibitor > C129825 - Antineoplastic Enzyme Inhibitor C274 - Antineoplastic Agent > C1742 - Angiogenesis Inhibitor C471 - Enzyme Inhibitor > C1404 - Protein Kinase Inhibitor

Ergomet

(6aR,9R)-N-[(2S)-1-hydroxypropan-2-yl]-7-methyl-6,6a,8,9-tetrahydro-4H-indolo[4,3-fg]quinoline-9-carboxamide;(Z)-but-2-enedioic acid

C29H19N3O2 (441.1477194)

Floridanine

Folic acid

C19H19N7O6 (441.1396754)

Folic acid (Vitamin B9) is a orally active essential nutrient from the B complex group of vitamins. Folic acid shows antidepressant-like effect. Folic acid sodium reduces the risk of neonatal neural tube defects. Folic acid can be used to the research of megaloblastic and macrocytic anemias due to folic deficiency[1][2][3][4]. Folic acid (Vitamin B9) is a orally active essential nutrient from the B complex group of vitamins. Folic acid shows antidepressant-like effect. Folic acid sodium reduces the risk of neonatal neural tube defects. Folic acid can be used to the research of megaloblastic and macrocytic anemias due to folic deficiency[1][2][3][4].

FOLIC ACID_major

C19H19N7O6 (441.1396754)

Ala His Asn Thr

(2S,3R)-2-[(2S)-2-[(2S)-2-[(2S)-2-aminopropanamido]-3-(1H-imidazol-4-yl)propanamido]-3-carbamoylpropanamido]-3-hydroxybutanoic acid