All Photos(3)




(6R)-5,6,7,8-Tetrahydrobiopterin dihydrochloride

Sign Into View Organizational & Contract Pricing

Empirical Formula (Hill Notation):
C9H15N5O3 · 2HCl
CAS Number:
Molecular Weight:
MDL number:
PubChem Substance ID:

Quality Level


water, oxygen free: soluble 19.60-20.40 mg/mL, clear to slightly hazy, colorless to faintly yellow

storage temp.


SMILES string




InChI key


Gene Information

human ... PAH(5053)

Compare Similar Items

View Full Comparison

Show Differences

1 of 4

This Item
p-Nitroblue Tetrazolium Chloride NADPH-diaphorase substrate that competitively inhibits nitric oxide synthase (IC₅₀ = 3-4 µM).


p-Nitroblue Tetrazolium Chloride

storage temp.


storage temp.


storage temp.


storage temp.



water, oxygen free: soluble 19.60-20.40 mg/mL, clear to slightly hazy, colorless to faintly yellow


water: 19.60-20.40 mg/mL, clear, colorless to faintly yellow


water: 50 mg/mL


methanol: soluble, water: soluble

Gene Information

human ... PAH(5053)

Gene Information

human ... PYGB(5834), PYGBL(5835), PYGL(5836), PYGM(5837)
mouse ... Gaa(14387), Glb1(12091), Treh(58866)
rat ... Man2a1(25478), Pygl(64035), Si(25588)

Gene Information


Gene Information


General description

Tetrahydrobiopterin is a natural cofactor for phenylalanine hydroxylase, tyrosine hydroxylase, tryptophan hydroxylase, nitric oxide synthase and alkylglycerol monooxygenase.


(6R)-BH4 has been used as a buffer component for assaying tyrosine hydroxylase enzyme activity in mouse brain tissues. (6R)-BH4 has also been identified as an activator compound from a LOPAC library screen using a fluorogenic α-glucosidase assay.

Biochem/physiol Actions

Lack of tetrahydrobiopterin may cause hyperphenylalaninemia. Diseases like, Parkinson′s, autism, depression and Alzheimer′s shows low concentration of tetrahydrobiopterin in the cerebrospinal fluid. This coenzyme participates in dopamine (DA) synthesis.

Features and Benefits

This compound is featured on the Dopamine, Norepinephrine and Epinephrine Synthesis and Nitric Oxide Synthases pages of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

Preparation Note

(6R)-5,6,7,8-Tetrahydrobiopterin dihydrochloride ((6R)-BH4 ) is soluble in oxygen free water at 19.60 - 20.40 mg/ml and yields a clear to slightly hazy, colorless to faint yellow solution.


Exclamation mark




Hazard Classifications

Acute Tox. 4 Oral

Storage Class

11 - Combustible Solids




Not applicable


Not applicable

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Documents related to the products that you have purchased in the past have been gathered in the Document Library for your convenience.

Visit the Document Library

Difficulty Finding Your Product Or Lot/Batch Number?

Product numbers are combined with Pack Sizes/Quantity when displayed on the website (example: T1503-25G). Please make sure you enter ONLY the product number in the Product Number field (example: T1503).


Product Number
Pack Size/Quantity

Additional examples:





enter as 1.000309185)

Having trouble? Feel free to contact Technical Service for assistance.

Lot and Batch Numbers can be found on a product's label following the words 'Lot' or 'Batch'.

Aldrich Products

  • For a lot number such as TO09019TO, enter it as 09019TO (without the first two letters 'TO').

  • For a lot number with a filling-code such as 05427ES-021, enter it as 05427ES (without the filling-code '-021').

  • For a lot number with a filling-code such as STBB0728K9, enter it as STBB0728 without the filling-code 'K9'.

Not Finding What You Are Looking For?

In some cases, a COA may not be available online. If your search was unable to find the COA you can request one.

Request COA

Customers Also Viewed

Slide 1 of 4

1 of 4

Tetrahydrobiopterin biosynthesis as a potential target of the kynurenine pathway metabolite xanthurenic acid
Haruki H, et al.
Test (2016)
Thomas Opladen et al.
Orphanet journal of rare diseases, 15(1), 126-126 (2020-05-28)
Tetrahydrobiopterin (BH4) deficiencies comprise a group of six rare neurometabolic disorders characterized by insufficient synthesis of the monoamine neurotransmitters dopamine and serotonin due to a disturbance of BH4 biosynthesis or recycling. Hyperphenylalaninemia (HPA) is the first diagnostic hallmark for most
Kamil Kostyn et al.
Antioxidants (Basel, Switzerland), 9(8) (2020-08-14)
Catecholamines are biogenic aromatic amines common among both animals and plants. In animals, they are synthesized via tyrosine hydroxylation, while both hydroxylation or decarboxylation of tyrosine are possible in plants, depending on the species, though no tyrosine hydroxylase-a counterpart of
Tetrahydrobiopterin biosynthesis as a potential target of the kynurenine pathway metabolite xanthurenic acid
Haruki H, et al.
The Journal of Biological Chemistry (2016)
Ailing Fu et al.
Brain research, 1352, 208-213 (2010-07-06)
Glial-derived neurotrophic factor (GDNF) is a trophic factor for the nigra-striatal tract in experimental Parkinson's disease (PD). The neurotrophin must be administered by intra-cerebral injection, because GDNF does not cross the blood-brain barrier (BBB). In the present study, GDNF was


Serotonin (5-hydroxytryptamine) is principally found stored in three main cell types - i) serotonergic neurons in the CNS and in the intestinal myenteric plexus, ii) enterochromaffin cells in the mucosa of the gastrointestinal tract, and iii) in blood platelets. Metabolism of serotonin is carried out primarily by the outer mitochondrial membrane enzyme monoamine oxidase (MAO), which occurs as two molecular subtypes called MAO-A and MAO-B.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service