(6R,S)-5,6,7,8-TETRAHYDRO-L-BIOPTERIN DIHYDROCHLORIDE

The Uses of (6R,S)-5,6,7,8-TETRAHYDRO-L-BIOPTERIN DIHYDROCHLORIDE

Treatment of mild-to-moderate phenylketonuria (PKU).

Indications

For the treatment of tetrahydrobiopterin (BH4) deficiency.

Background

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.

Definition

ChEBI: Sapropterin is 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,1'R,2'S-enantiomer). It has a role as a coenzyme, a diagnostic agent, a human metabolite and a cofactor.

Pharmacokinetics

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.

Metabolism

Not Available