Gene Association: QDPR

UniProt Search: QDPR (PROTEIN_CODING)
Function Description: quinoid dihydropteridine reductase

found 20 associated metabolites with current gene based on the text mining result from the pubmed database.

5-Hydroxy-L-tryptophan

(S)-2-Amino-3-(5-hydroxy-1H-indol-3-yl)propanoic Acid (5-Hydroxytryptophan)

C11H12N2O3 (220.0848)


5-Hydroxy-L-tryptophan is an aromatic amino acid naturally produced by the body from the essential amino acid L-tryptophan. 5-Hydroxy-L-tryptophan is the immediate precursor of the neurotransmitter serotonin. The conversion to serotonin is catalyzed by the enzyme aromatic L-amino acid decarboxylase (EC 4.1.1.28) (AADC1 also known as DOPA decarboxylase), an essential enzyme in the metabolism of the monoamine neurotransmitters. An accumulation of 5-hydroxy-L-tryptophan in cerebrospinal fluid occurs in aromatic L-amino acid decarboxylase deficiency (AADC deficiency) (OMIM: 608643) accompanied by an increased excretion in the urine of the patients, which are indicative of the disorder but not specific. 5-Hydroxy-L-tryptophan is also increased in other disorders such as in Parkinsons patients with severe postural instability and gait disorders. The amount of endogenous 5-hydroxy-L-tryptophan available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase (EC 1.14.16.4), indoleamine 2,3-dioxygenase (EC 1.13.11.52), and tryptophan 2,3-dioxygenase (TDO) (EC 1.13.11.11). 5-Hydroxy-L-tryptophan has been used clinically for over 30 years. In addition to its use in the treatment of depression, the therapeutic administration of 5-hydroxy-L-tryptophan has been shown to be effective in treating a wide variety of conditions, including fibromyalgia, insomnia, binge eating associated with obesity, cerebellar ataxia, and chronic headaches. 5-Hydroxy-L-tryptophan easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. Supplementation with 5-hydroxy-L-tryptophan is hypothesized to normalize serotonin synthesis, which is putatively related to its antidepressant properties (PMID: 9295177, 17240182, 16023217). When present in sufficiently high levels, 5-hydroxytryptophan can be a neurotoxin and a metabotoxin. A neurotoxin is a compound that disrupts or attacks neural cells or tissue. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Signs and symptoms of AADC deficiency generally appear in the first year of life. Affected infants may have severe developmental delay, weak muscle tone (hypotonia), muscle stiffness, difficulty moving, and involuntary writhing movements of the limbs (athetosis). They may be lacking in energy (lethargic), feed poorly, startle easily, and have sleep disturbances. Since 5-hydroxytryptophan is a precursor to serotonin, altered levels of serotonin can accumulate in the brain, which leads to abnormal neural signalling. Infants with AADC deficiency have very low levels of neural signalling molecules while individuals who consume high levels of 5-hydroxytryptophan will have very high levels of neural signalling molecules. Both conditions can lead to vomiting, nausea, extreme drowsiness, and lethargy. 5-Hydroxytryptophan (5-HTP), also known as oxitriptan (INN) is sold over-the-counter in the United Kingdom, the United States, and Canada as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under trade names such as Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. Several double-blind placebo-controlled clinical trials have demonstrated the effectiveness of 5-HTP in the treatment of depression, though a lack of high-quality studies has been noted. More and larger studies are needed to determine if 5-HTP is truly effective in treating depression. 5-hydroxy-L-tryptophan is the L-enantiomer of 5-hydroxytryptophan. It has a role as a human metabolite, a plant metabolite and a mouse metabolite. It is a 5-hydroxytryptophan, a hydroxy-L-tryptophan and a non-proteinogenic L-alpha-amino acid. It is an enantiomer of a 5-hydroxy-D-tryptophan. It is a tautomer of a 5-hydroxy-L-tryptophan zwitterion. 5-Hydroxytryptophan (5-HTP), also known as oxitriptan (INN), is a naturally occurring amino acid and metabolic intermediate in the synthesis of serotonin and melatonin. 5-HTP is sold over-the-counter in the United Kingdom, United States and Canada as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid, and is also marketed in many European countries for the indication of major depression under trade names like Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. Several double-blind placebo-controlled clinical trials have demonstrated the effectiveness of 5-HTP in the treatment of depression, though a lack of high quality studies has been noted. More study is needed to determine efficacy in treating depression. Oxitriptan is an aromatic amino acid with antidepressant activity. In vivo, oxitriptan (or 5-hydroxytryptophan) is converted into 5-hydroxytryptamine (5-HT or serotonin) as well as other neurotransmitters. Oxitriptan may exert its antidepressant activity via conversion to serotonin or directly by binding to serotonin (5-HT) receptors within the central nervous system (CNS). Endogenous oxitriptan is produced from the essential amino acid L-tryptophan. The exogenous therapeutic form is isolated from the seeds of the African plant Griffonia simplicifolia. The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant. See also: ... View More ... 5-Hydroxytryptophan (5-HTP), also known as oxitriptan (INN), is a naturally-occurring amino acid and chemical precursor as well as metabolic intermediate in the biosynthesis of the neurotransmitters serotonin and melatonin from tryptophan. 5-Hydroxy-L-tryptophan is found in french plantain. 5-Hydroxy-L-tryptophan. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=4350-09-8 (retrieved 2024-07-02) (CAS RN: 4350-09-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-5-Hydroxytryptophan (L-5-HTP), a naturally occurring amino acid and a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid, is the immediate precursor of the neurotransmitter serotonin and a reserpine antagonist[1]. L-5-Hydroxytryptophan (L-5-HTP) is used to treat fibromyalgia, myoclonus, migraine, and cerebellar ataxia[2][3][4][5].

   

5-Hydroxytryptophan

(S)-2-Amino-3-(5-hydroxy-1H-indol-3-yl)-propionic acid;C5-Hydroxy-L-tryptophan;5-HTP;Oxitriptan

C11H12N2O3 (220.0848)


5-hydroxytryptophan is a tryptophan derivative that is tryptophan substituted by a hydroxy group at position 5. It has a role as a human metabolite and a neurotransmitter. 5-Hydroxytryptophan, DL- is a racemic mixture of 5-hydroxytryptophan (5-HTP), a precursor to the neurotransmitter serotonin with anti-depressant, analgesic and appetite-suppressant activities. DL-5-HTP is decarboxylated to serotonin by aromatic-L-amino-acid decarboxylase, and results in increased serotonin levels within the brain. Mediated through serotonin receptors, elevated levels of serotonin causes increased serotonin neurotransmissions, hence leading to release of depression, pain and appetite. 5-Hydroxy-L-tryptophan is an aromatic amino acid naturally produced by the body from the essential amino acid l-tryptophan. 5-Hydroxy-L-tryptophan is the immediate precursor of the neurotransmitter serotonin. The conversion to serotonin is catalyzed by the enzyme aromatic l-amino acid decarboxylase (EC 4.1.1.28, AADC1 also known as dopa decarboxylase), an essential enzyme in the metabolism of the monoamine neurotransmitters. An accumulation of 5-Hydroxy-L-tryptophan in cerebrospinal fluid occurs in Aromatic l-amino acid decarboxylase deficiency (OMIM 608643), accompanied by an increased excretion in the urine of the patients, which are indicative of the disorder but not specific 5-Hydroxy-L-tryptophan is also increased in other disorders such as in Parkinsons patients with severe postural instability and gait disorders. Confirmation of the diagnosis AADC deficiency is then required by enzyme activity measurement or genetic analysis. The amount of endogenous 5-Hydroxy-L-tryptophan available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase (EC 1.14.16.4), indoleamine 2,3-dioxygenase (EC 1.13.11.52), and tryptophan 2,3-dioxygenase. (EC 1.13.11.11, TDO). 5-Hydroxy-L-tryptophan has been used clinically for over 30 years. In addition to depression, the therapeutic administration of 5-Hydroxy-L-tryptophan has been shown to be effective in treating a wide variety of conditions, including fibromyalgia, insomnia, binge eating associated with obesity, cerebellar ataxia, and chronic headaches. 5-Hydroxy-L-tryptophan easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. Supplementation with 5-Hydroxy-L-tryptophan is hypothesized to normalize serotonin synthesis, which is putatively related to its antidepressant properties. (A3384, A3385, A3386). The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant. D002491 - Central Nervous System Agents > D011619 - Psychotropic Drugs > D000928 - Antidepressive Agents A tryptophan derivative that is tryptophan substituted by a hydroxy group at position 5. 5-Hydroxytryptophan, a tryptophan metabolite, is a direct 5-hydroxytryptamine (5-HT) precursor and an L-aromatic amino acid decarboxylase substrate. [1][2][3]. 5-Hydroxytryptophan, a tryptophan metabolite, is a direct 5-hydroxytryptamine (5-HT) precursor and an L-aromatic amino acid decarboxylase substrate. [1][2][3].

   

Tetrahydrobiopterin

(-)-(6R)-2-Amino-6-((1R,2S)-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4(3H)-pteridinone

C9H15N5O3 (241.1175)


Tetrahydrobiopterin (CAS: 17528-72-2), also known as BH4, is an essential cofactor in the synthesis of neurotransmitters and nitric oxide (PMID: 16946131). In fact, it is used by all three human nitric-oxide synthases (NOS) eNOS, nNOS, and iNOS as well as the enzyme glyceryl-ether monooxygenase. It is also essential in the conversion of phenylalanine into tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine into L-dopa by the enzyme tyrosine hydroxylase; and the conversion of tryptophan into 5-hydroxytryptophan via tryptophan hydroxylase. Specifically, tetrahydrobiopterin is a cofactor for tryptophan 5-hydroxylase 1, tyrosine 3-monooxygenase, and phenylalanine hydroxylase, all of which are essential for the formation of the neurotransmitters dopamine, noradrenaline, and adrenaline. Tetrahydrobiopterin has been proposed to be involved in the promotion of neurotransmitter release in the brain and the regulation of human melanogenesis. A defect in BH4 production and/or a defect in the enzyme dihydropteridine reductase (DHPR) causes phenylketonuria type IV, as well as dopa-responsive dystonias. BH4 is also implicated in Parkinsons disease, Alzheimers disease, and depression. Tetrahydrobiopterin is present in probably every cell or tissue of higher animals. On the other hand, most bacteria, fungi and plants do not synthesize tetrahydrobiopterin (Wikipedia). A - Alimentary tract and metabolism > A16 - Other alimentary tract and metabolism products > A16A - Other alimentary tract and metabolism products > A16AX - Various alimentary tract and metabolism products C26170 - Protective Agent > C275 - Antioxidant Tetrahydrobiopterin ((Rac)-Sapropterin) is a cofactor of the aromatic amino acid hydroxylases enzymes and also acts as an essential cofactor for all nitric oxide synthase (NOS) isoforms.

   

d-Threo biopterin

2-amino-6-[(1R,2S)-1,2-dihydroxypropyl]-1,4-dihydropteridin-4-one

C9H11N5O3 (237.0862)


6-Biopterin (L-Biopterin), a pterin derivative, is a NO synthase cofactor.

   

Sepiapterin

2-Amino-7,8-dihydro-6-((2S)-2-hydroxy-1-oxopropyl)-4(3H)-pteridinone acid

C9H11N5O3 (237.0862)


Sepiapterin, also known as 2-amino-6-lactoyl-7,8-dihydropteridin-4(3H)-one, belongs to the class of organic compounds known as pterins and derivatives. These are polycyclic aromatic compounds containing a pterin moiety, which consist of a pteridine ring bearing a ketone and an amine group to form 2-aminopteridin-4(3H)-one. Sepiapterin is also classified as a member of the pteridine class of organic chemicals. It is a yellow fluorescing pigment. Sepiapterin is an intermediate in the salvage pathway of tetrahydrobiopterin (BH(4)). More specifically, sepiapterin can be metabolized into tetrahydrobiopterin via the BH(4) salvage pathway. Tetrahydrobiopterin is an essential cofactor in humans for breakdown of phenylalanine and a catalyst of the metabolism of phenylalanine, tyrosine, and tryptophan to the neurotransmitters dopamine and serotonin. A deficiency of tetrahydrobiopterin can cause toxic buildup of phenylalanine (phenylketonuria) as well as deficiencies of dopamine, norepinephrine, and epinephrine, leading to dystonia and other neurological illnesses. Sepiapterin accumulates in the brain of patients with sepiapterin reductase (SR) deficiency, an inborn error of metabolism. Sepiapterin reductase deficiency is a condition characterized by movement problems, most often a pattern of involuntary, sustained muscle contractions known as dystonia. Other movement problems can include muscle stiffness (spasticity), tremors, problems with coordination and balance (ataxia), and involuntary jerking movements (chorea). People with sepiapterin reductase deficiency can experience episodes called oculogyric crises. These episodes involve abnormal rotation of the eyeballs; extreme irritability and agitation; and pain, muscle spasms, and uncontrolled movements, especially of the head and neck. Movement abnormalities are often worse late in the day. Most affected individuals have delayed development of motor skills such as sitting and crawling, and they typically are not able to walk unassisted. The problems with movement tend to worsen over time. Within humans, sepiapterin participates in a number of enzymatic reactions. In particular, sepiapterin can be converted into 7,8-dihydroneopterin; which is mediated by the enzyme sepiapterin reductase. In addition, sepiapterin can be converted into 7,8-dihydroneopterin through its interaction with the enzyme carbonyl reductase [NADPH] 1. Sepiapterin is an intermediate in the salvage pathway of tetrahydrobiopterin (BH(4)). It is a yellow fluorescing pigment. Sepiapterin accumulates in the brain of patients with sepiapterin reductase (SR) deficiency. [HMDB] C307 - Biological Agent

   

Dihydrobiopterin

2-amino-6-[(1R,2S)-1,2-dihydroxypropyl]-1,4,7,8-tetrahydropteridin-4-one

C9H13N5O3 (239.1018)


Dihydrobiopterin, also known as BH2, 7,8-dihydrobiopterin, L-erythro-7,8-dihydrobiopterin, quinonoid dihydrobiopterin or q-BH2, belongs to the class of organic compounds known as biopterins and derivatives. These are coenzymes containing a 2-amino-pteridine-4-one derivative. Dihydrobiopterin is also classified as a pteridine. Pteridines are aromatic compounds composed of fused pyrimidine and pyrazine rings. Dihydrobiopterin is produced during the synthesis of neurotransmitters L-DOPA, dopamine, norepinephrine and epinephrine. It is restored to the required cofactor tetrahydrobiopterin via the NADPH-dependant reduction of dihydrobiopterin reductase. Dihydrobiopterin can also be converted to tetrahydrobiopterin by nitric oxide synthase (NOS) which is catalyzed by the flavoprotein "diaphorase" activity of NOS. This activity is located on the reductase (C-terminal) domain of NOS, whereas the high affinity tetrahydrobiopterin site involved in NOS activation is located on the oxygenase (N-terminal) domain (PMID: 8626754). Sepiapterin reductase (SPR) is another enzyme that plays a role in the production of dihydrobiopterin. SPR catalyzes the reduction of sepiapterin to dihydrobiopterin (BH2), the precursor for tetrahydrobiopterin (BH4). BH4 is a cofactor critical for nitric oxide biosynthesis and alkylglycerol and aromatic amino acid metabolism (PMID: 25550200). Dihydrobiopterin is known to be synthesized in several parts of the body, including the pineal gland. Dihydrobiopterin exists in all eukaryotes, ranging from yeast to humans. In humans, dihydrobiopterin is involved in several metabolic disorders including dihydropteridine reductase (DHPR) deficiency. DHPR deficiency is a severe form of hyperphenylalaninemia (HPA) due to impaired regeneration of tetrahydrobiopterin (BH4) leading to decreased levels of neurotransmitters (dopamine, serotonin) and folate in cerebrospinal fluid, and causing neurological symptoms such as psychomotor delay, hypotonia, seizures, abnormal movements, hypersalivation, and swallowing difficulties. Dihydrobiopterin is also associated with another metabolic disorder known as sepiapterin reductase deficiency (SRD). Sepiapterin reductase catalyzes the (NADP-dependent) reduction of carbonyl derivatives, including pteridines, and plays an important role in tetrahydrobiopterin biosynthesis. Low dihydrofolate reductase activity in the brain leads to the accumulation of dihydrobiopterin, which in turn, inhibits tyrosine and tryptophan hydroxylases. This uncouples neuronal nitric oxide synthase, leading to neurotransmitter deficiencies and neuronal cell death. SRD is characterized by low cerebrospinal fluid neurotransmitter levels and the presence of elevated cerebrospinal fluid dihydrobiopterin. SRD is characterized by motor delay, axial hypotonia, language delay, diurnal fluctuation of symptoms, dystonia, weakness, oculogyric crises, dysarthria, parkinsonian signs and hyperreflexia. Dihydrobiopterin (BH2) is an oxidation product of tetrahydrobiopterin. Tetrahydrobiopterin is a natural occurring cofactor of the aromatic amino acid hydroxylase and is involved in the synthesis of tyrosine and the neurotransmitters dopamine and serotonin. Tetrahydrobiopterin is also essential for nitric oxide synthase catalyzed oxidation of L-arginine to L-citrulline and nitric oxide. [HMDB] 7,8-Dihydro-L-biopterin is an oxidation product of tetrahydrobiopterin.

   

Pterin

2-amino-3,4-dihydropteridin-4-one

C6H5N5O (163.0494)


Pterin is a chemical compound composed of a pyrazine ring and a pyrimidine ring; Pterin is a heterocyclic compound composed of a pyrazine ring and a pyrimidine ring (a pteridine ring system); the pyrimidine ring has a carbonyl oxygen and an amino group. Several tautomers of pterin exist and are shown below. As a group, pterins are compounds that are derivatives of 2-amino-4-oxopteridine, with additional functional groups attached to the pyrazine ring.; the pyrimidine ring has a carbonyl oxygen and an amino group. Several tautomers of pterin exist and are shown below. Pterin belongs to the pteridine family of heterocycles. -- Wikipedia. Pterin is found in soy bean. Pterin is a chemical compound composed of a pyrazine ring and a pyrimidine ring; the pyrimidine ring has a carbonyl oxygen and an amino group. Several tautomers of pterin exist and are shown below. Pterin belongs to the pteridine family of heterocycles. -- Wikipedia.

   

Dihydropteridine

6,7-dihydropteridine

C6H6N4 (134.0592)


Dihydropteridine is a generic compound; the product of the reduction of 5,6,7,8-Tetrahydropteridine, which is catalyzed by 6,7-dihydropteridine reductase (EC 1.5.1.34). (KEGG) This compound is recognised as a cause of tetrahydrobiopterin (BH(4)) deficiency, leading to hyperphenylalaninemia (HPA) and impaired biogenic amine deficiency. (PMID: 14705166). A generic compound; the product of the reduction of 5,6,7,8-Tetrahydropteridine, which is catalyzed by 6,7-dihydropteridine reductase (EC 1.5.1.34). (KEGG) This compound is recognised as a cause of tetrahydrobiopterin (BH(4)) deficiency, leading to hyperphenylalaninemia (HPA) and impaired biogenic amine deficiency. (PMID: 14705166) [HMDB]

   

Tetrahydropteridine

5,6,7,8-Tetrahydro-pteridine

C6H8N4 (136.0749)


Tetrahydrobiopterin serves well-characterized cofactor functions for hydroxylating aromatic amino acids and ether lipids and for formation of nitric oxide (NO) from L-arginine. Formation of NO involves two cycles of oxidation of Tetrahydrobiopterin to its radical with subsequent rehydroxylation into Tetrahydrobiopterin, one for reduction of the heme-bound arginine-Fe(II)O2 complex of NO synthase (NOS), the other for reduction of the N-hydroxy-L-arginine-Fe(II)O2 complex. Tetrahydrobiopterin-dependent glyceryl ether monooxygenase (EC 1.14.16.5) is found not only in liver and the gastrointestinal tract but also in brain and other organs (this enzyme plays an essential role in conjugation with the cleavage enzyme in the regulation of cellular levels of -alkyl moieties in glycerolipids). Tetrahydrobiopterin is essential for the enzymatic reaction of tyrosine 3-monooxygenase (EC 1.14.16.2) for the first step in the biosynthesis of catecholamines such as norepinephrine, epinephrine and dopamine. Limited Tetrahydrobiopterin availability not only decreases formation of NO but also causes NOS-derived superoxide/hydrogen peroxide production leading to formation of peroxynitrite as well as S-nitrosoglutathione. As a consequence of its oxygen-activating potential, Tetrahydrobiopterin is also subject to autoxidation in a free radical chain reaction in leading to formation of superoxide and finally to hydrogen peroxide. On the other hand, Tetrahydrobiopterin, like other H4-pterins, can scavenge reactive oxygen species and peroxynitrite. Thus, Tetrahydrobiopterin may have opposing effects in various biological systems depending on whether its cofactor roles outweigh its chemical reactivity or vice versa. Sepiapterin reductase (EC 1.1.1.153) catalyzes the reduction of tetrahydro-sepiapterin to tetrahydrobiopterin -the terminal step in this biosynthetic pathway for tetrahydrobiopterin. This reaction is N-acetyl-serotonin-sensitive and can completely inhibit tetrahydrobiopterin synthesis. (PMID: 3881214, 17303893, 3756924, 15223071) [HMDB] Tetrahydrobiopterin serves well-characterized cofactor functions for hydroxylating aromatic amino acids and ether lipids and for formation of nitric oxide (NO) from L-arginine. Formation of NO involves two cycles of oxidation of Tetrahydrobiopterin to its radical with subsequent rehydroxylation into Tetrahydrobiopterin, one for reduction of the heme-bound arginine-Fe(II)O2 complex of NO synthase (NOS), the other for reduction of the N-hydroxy-L-arginine-Fe(II)O2 complex. Tetrahydrobiopterin-dependent glyceryl ether monooxygenase (EC 1.14.16.5) is found not only in liver and the gastrointestinal tract but also in brain and other organs (this enzyme plays an essential role in conjugation with the cleavage enzyme in the regulation of cellular levels of -alkyl moieties in glycerolipids). Tetrahydrobiopterin is essential for the enzymatic reaction of tyrosine 3-monooxygenase (EC 1.14.16.2) for the first step in the biosynthesis of catecholamines such as norepinephrine, epinephrine and dopamine. Limited Tetrahydrobiopterin availability not only decreases formation of NO but also causes NOS-derived superoxide/hydrogen peroxide production leading to formation of peroxynitrite as well as S-nitrosoglutathione. As a consequence of its oxygen-activating potential, Tetrahydrobiopterin is also subject to autoxidation in a free radical chain reaction in leading to formation of superoxide and finally to hydrogen peroxide. On the other hand, Tetrahydrobiopterin, like other H4-pterins, can scavenge reactive oxygen species and peroxynitrite. Thus, Tetrahydrobiopterin may have opposing effects in various biological systems depending on whether its cofactor roles outweigh its chemical reactivity or vice versa. Sepiapterin reductase (EC 1.1.1.153) catalyzes the reduction of tetrahydro-sepiapterin to tetrahydrobiopterin -the terminal step in this biosynthetic pathway for tetrahydrobiopterin. This reaction is N-acetyl-serotonin-sensitive and can completely inhibit tetrahydrobiopterin synthesis. (PMID: 3881214, 17303893, 3756924, 15223071).

   

Pteridine

1,3,5,8-Tetraazanaphthalene

C6H4N4 (132.0436)


   

Biopterin

2-amino-6-[(1R,2S)-1,2-dihydroxypropyl]-4,8-dihydropteridin-4-one

C9H11N5O3 (237.0862)


Biopterin concentrations in cerebrospinal fluid from patients with Parkinsons disease, in which the nigrostriatal dopamine neurons degenerate, are lower than those from age-matched older controls. In hereditary progressive dystonia/DOPA-responsive dystonia, which is a dopamine deficiency caused by mutations in GTP cyclohydrolase I without neuronal cell death (Segawas disease), biopterin in cerebrospinal fluid decrease in parallel owing to the decreased activity in GTP cyclohydrolase I (EC 3.5.4.16, is an enzyme that is part of the folate and biopterin biosynthesis pathways. It is responsible for the hydrolysis of guanosine triphosphate (GTP) to form 7,8-dihydroneopterin 3-triphosphate. (Pteridines (1999), 10(1), 5-13.) Lowered levels of urinary biopterin concomitant with elevated serum phenylalanine concentration occur in a variant type of hyperphenylalaninemia caused by a deficiency of tetrahydrobiopterin (BH4), the obligatory cofactor for phenylalanine hydroxylase. The most frequent form of this cofactor deficiency is due to lack of 6-pyruvoyl-tetrahydropterin synthase (PTPS) activity, the second enzyme in the biosynthetic pathway for BH4. (PMID 8178819) The hepatic phenylalanine hydroxylating system consists of 3 essential components, phenylalanine hydroxylase, dihydropteridine reductase, and the nonprotein coenzyme, tetrahydrobiopterin. The reductase and the pterin coenzyme are also essential components of the tyrosine and tryptophan hydroxylating systems. There are 3 distinct forms of phenylketonuria or hyperphenylalaninemia, each caused by lack of 1 of these essential components. The variant forms of the disease that are caused by the lack of dihydropteridine reductase or tetrahydrobiopterin are characterized by severe neurol. deterioration, impaired functioning of tyrosine and tryptophan hydroxylases, and the resultant deficiency of tyrosine- and tryptophan-derived monoamine neurotransmitters in brain. (PMID 3930837) [HMDB] Biopterin, also known as tetrahydrobiopterin or BH4, belongs to the class of organic compounds known as biopterins and derivatives. These are coenzymes containing a 2-amino-pteridine-4-one derivative. Biopterin or tetrahydrobiopterin is also classified as a pterin derivative that consists of pterin group bearing an amino, an oxo and a 1,2-dihydroxypropyl substituent at positions 2, 4 and 6, respectively. Biopterin compounds found within the animals include BH4 (tetrahydrobiopterin), the free radical BH3, and BH2 (also a free radical, called Dihydrobiopterin). BH2 is produced in the synthesis of L-DOPA, dopamine, norepinephrine and epinephrine. It is restored to the required cofactor tetrahydrobiopterin by the enzyme dihydrobiopterin reductase. Tetrahydrobiopterin (BH4) 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). It is also a cofactor for the production of nitric oxide (NO) by the nitric oxide syntheses. Tetrahydrobiopterin is biosynthesized from guanosine triphosphate (GTP) by three chemical reactions mediated by the enzymes GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR). Biopterin synthesis disorders are a cause of hyperphenylalaninemia. There are 3 distinct forms of phenylketonuria or hyperphenylalaninemia, each caused by lack of aromatic amino acid hydroxylase enzymes. The variant forms of hyperphenylalaninemia that are caused by the lack of dihydropteridine reductase or tetrahydrobiopterin are characterized by severe neurological deterioration, impaired functioning of tyrosine and tryptophan hydroxylases, and the resultant deficiency of tyrosine- and tryptophan-derived monoamine neurotransmitters in brain. (PMID 3930837). 6-Biopterin (L-Biopterin), a pterin derivative, is a NO synthase cofactor.

   

Oxitriptan

L-5-Hydroxytryptophan

C11H12N2O3 (220.0848)


D002491 - Central Nervous System Agents > D011619 - Psychotropic Drugs > D000928 - Antidepressive Agents relative retention time with respect to 9-anthracene Carboxylic Acid is 0.053 N - Nervous system > N06 - Psychoanaleptics > N06A - Antidepressants relative retention time with respect to 9-anthracene Carboxylic Acid is 0.054 L-5-Hydroxytryptophan (L-5-HTP), a naturally occurring amino acid and a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid, is the immediate precursor of the neurotransmitter serotonin and a reserpine antagonist[1]. L-5-Hydroxytryptophan (L-5-HTP) is used to treat fibromyalgia, myoclonus, migraine, and cerebellar ataxia[2][3][4][5].

   

biopterin

6-Biopterin

C9H11N5O3 (237.0862)


A pterin derivative that consists of pterin bearing amino, oxo and 1,2-dihydroxypropyl substituents at positions 2, 4 and 6 respectively. The parent of the class of biopterins; the L-erythro isomer occurs widely in nature. 6-Biopterin (L-Biopterin), a pterin derivative, is a NO synthase cofactor.

   

dihydrobiopterin

7,8-Dihydro-L-biopterin

C9H13N5O3 (239.1018)


7,8-Dihydro-L-biopterin is an oxidation product of tetrahydrobiopterin.

   

Sepiapterin

L-Sepiapterin

C9H11N5O3 (237.0862)


C307 - Biological Agent

   

Pterin

2-aminopteridin-4-ol

C6H5N5O (163.0494)


   

Sapropterin

Sapropterin

C9H15N5O3 (241.1175)


A - Alimentary tract and metabolism > A16 - Other alimentary tract and metabolism products > A16A - Other alimentary tract and metabolism products > A16AX - Various alimentary tract and metabolism products A tetrahydropterin that is 2-amino-5,6,7,8-tetrahydropteridin-4(3H)-one in which a hydrogen at position 6 is substituted by a 1,2-dihydroxypropyl group (6R,1R,2S-enantiomer). C26170 - Protective Agent > C275 - Antioxidant Sapropterin is converted from 7,8-dihydroneopterin triphosphate by 6-pyruvoyl tetrahydropterin synthase and sepiapterin reductase. It is essential in the formation of neurotransmitters and for nitric oxide synthase (PMID 16946131). [HMDB] Tetrahydrobiopterin ((Rac)-Sapropterin) is a cofactor of the aromatic amino acid hydroxylases enzymes and also acts as an essential cofactor for all nitric oxide synthase (NOS) isoforms.

   

PTERIDINE

PTERIDINE

C6H4N4 (132.0436)


   

5,6,7,8-tetrahydropteridine

5,6,7,8-tetrahydropteridine

C6H8N4 (136.0749)


   

6,7-dihydropteridine

6,7-dihydropteridine

C6H6N4 (134.0592)