Repositioning Candidate Details

Candidate ID: R0129
Source ID: DB00360
Source Type: approved; investigational
Compound Type: small molecule
Compound Name: Sapropterin
Synonyms: (−)-(6R)-2-amino-6-((1R,2S)-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4(3H)-pteridinone; (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin; (6R)-L-erythro-tetrahydrobiopterin; 2-Amino-6-(1,2-dihydroxypropyl)-5,6,7,8-tetrahydoro-4(1H)-pteridinone; 5,6,7,8-Tetrahydrobiopterin; 6R-5,6,7,8-tetrahydrobiopterin; 6R-BH4; 6R-L-5,6,7,8-tetrahydrobiopterin; R-THBP; Sapropterin; Tetrahydrobiopterin
Molecular Formula: C9H15N5O3
SMILES: [H][C@@]1(CNC2=C(N1)C(=O)NC(N)=N2)[C@@H](O)[C@H](C)O
Structure:
DrugBank Description: Sapropterin (tetrahydrobiopterin or BH4) is a cofactor in the synthesis of nitric oxide. It is also essential in the conversion of phenylalanine to tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine to L-dopa by the enzyme tyrosine hydroxylase; and conversion of tryptophan to 5-hydroxytryptophan via tryptophan hydroxylase.
CAS Number: 62989-33-7
Molecular Weight: 241.2471
DrugBank Indication: For the treatment of tetrahydrobiopterin (BH4) deficiency.
DrugBank Pharmacology: Tetrahydrobiopterin (BH4) is used to convert several amino acids, including phenylalanine, to other essential molecules in the body including neurotransmitters. Tetrahydrobiopterin deficiency can be caused by mutations in GTP cyclohydrolase 1 (GCH1), 6-pyruvoyl-tetrahydropterin synthase/dimerization cofactor of hepatocyte nuclear factor 1 alpha (PCBD1), 6-pyruvoyltetrahydropterin synthase (PTS), and quinoid dihydropteridine reductase (QDPR) genes. These genes make the enzymes that are critical for producing and recycling tetrahydrobiopterin. If one of the enzymes fails to function correctly because of a gene mutation, little or no tetrahydrobiopterin is produced. As a result, phenylalanine from the diet builds up in the bloodstream and other tissues and can damage nerve cells in the brain. High levels of phenylalanine can result in signs and symptoms ranging from temporary low muscle tone to mental retardation, movement disorders, difficulty swallowing, seizures, behavioral problems, progressive problems with development, and an inability to control body temperature.
DrugBank MoA: Tetrahydrobiopterin (BH4) is a natural co-factor or co-enzyme for phenylalanine-4-hydroxylase (PAH),Tetrahydrobiopterine, and tryptophan-5-hydroxylase. Tetrahydrobiopterin is also a natural co-factor for nitrate oxide synthase. Therefore BH4 is required for the conversion of phenylalanine to tyrosine, for the production of epinephrine (adrenaline) and the synthesis of the monoamine neuro-transmitters, serotonin, dopamine, and norepinephrine (noradrenaline). It is also involved in apoptosis and other cellular events mediated by nitric oxide production. As a coenzyme, BH4 reacts with molecular oxygen to form an active oxygen intermediate that can hydroxylate substrates. In the hydroxylation process, the co-enzyme loses two electrons and is regenerated in vivo in an NADH-dependent reaction. As a co-factor for PAH, tetrahydrobiopterin allows the conversion of phenylalanine to tyrosine and reduces the level of phenylalanine in the bloodstream, thereby reducing the toxic effects of of this amino acid. Normal serum concentrations of phenylalanine are 100 micomolar, while elevated (toxic) levels are typically >1200 micromolar. Individuals with a deficiency in tetrahydrobiopterin are not able to efficiently convert phenylalanine to tyrosine. The excess levels provided by tetrahydrobiopterin supplementation help improve enzyme efficiency. As a co-factor for tyrosine hydroxylase, BH4 facilitates the conversion of tyrosine to L-dopa while as a co-factor for tryptophan hydroxylase, BH4 allows the conversion of tryptophan to 5-hydroxytryptophan, which is then converted to serotonin.
Targets: Phenylalanine-4-hydroxylase cofactor; Nitric oxide synthase, endothelial cofactor; Tyrosine 3-monooxygenase cofactor; Tryptophan 5-hydroxylase 1 cofactor
Inclusion Criteria: Therapeutic strategy associated