Sepiapterin, also known as 2-amino-6- 2''S'')-2-hydroxypropanoyl7,8-dihydro-1''H''-pteridin-4-one, is a member of the

pteridine Pteridine is an aromatic chemical compound composed of fused pyrimidine and pyrazine rings. A pteridine is also a group of heterocyclic compounds containing a wide variety of substitutions on this structure. Pterins and flavins are classes of su ...

class of organic chemicals. Sepiapterin can be metabolized into tetrahydrobiopterin via a

salvage pathway A salvage pathway is a Metabolic pathway, pathway in which a biological product is produced from intermediates in the degradative pathway of its own or a similar substance. The term often refers to nucleotide salvage in particular, in which nucleoti ...

. Tetrahydrobiopterin is an essential cofactor in humans for breakdown of phenylalanine and a catalyst of the metabolism of phenylalanine, tyrosine, and tryptophan to precursors of the

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neuro ...

dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic compound, organic chemical of the catecholamine and phenethylamine families. Dopamine const ...

and

serotonin Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

. Deficiency of tetrahydrobiopterin can cause toxic buildup of

phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula . It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino a ...

(

phenylketonuria Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also resu ...

) as well as deficiencies of

norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', ...

, and

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...

, leading to

dystonia Dystonia is a neurological hyperkinetic movement disorder in which sustained or repetitive muscle contractions result in twisting and repetitive movements or abnormal fixed postures. The movements may resemble a tremor. Dystonia is often inten ...

and other neurological illnesses. This has led to clinical study of sepiapterin in humans to treat tetrahydrobiopterin deficiency. Since atherosclerosis and other circulatory diseases associated with

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

are also associated with tetrahydrobiopterin deficiency, animal studies of the value of sepiaterin in these vascular diseases have been done. These studies show that relaxation of the blood vessels studied was impaired after animals were given sepiapterin, even though their levels of tetrahydrobiopterin were replenished.

References

Pteridines Secondary alcohols Ketones Lactams {{ketone-stub

See also

References