Pteridines

A pteridine is a bicyclic heterocyclic system with two nitrogen atoms at positions 1 and 4 in ring A, and two nitrogen atoms at positions 1 and 3 in ring B. Pteridines constitute a large group of heterocyclic compounds containing a wide variety of substituents on this parent structure. Pterins and flavins are classes of substituted pteridines that have diverse biological roles.

Tetrahydrobiopterin (BH4, THB), also known as sapropterin (INN), is a cofactor of the three aromatic amino acid hydroxylase enzymes, used in the metabolism of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT), melatonin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and is a cofactor for the production of nitric oxide (NO) by the nitric oxide synthases. Chemically, its structure is that of a (dihydropteridine reductase) reduced pteridine derivative (quinonoid dihydrobiopterin).

Pterin is a heterocyclic compound composed of a pteridine ring system, with a "keto group" (a lactam) and an amino group on positions 4 and 2 respectively. It is structurally related to the parent bicyclic heterocycle called pteridine. Pterins, as a group, are compounds related to pterin with additional substituents. Pterin itself is of no biological significance.

Triamterene (traded under names such as Dyrenium and Dytac) is a potassium-sparing diuretic often used in combination with thiazide diuretics for the treatment of high blood pressure or swelling. The combination with hydrochlorothiazide, is known as hydrochlorothiazide/triamterene.

thumb|upright=1.25|Four steps of molybdenum cofactor (Moco) biosynthetic pathway occurring in bacteria and humans: (i) radical-mediated cyclization guanosine 5'-triphosphate (GTP) to (8S)‑3,8‐cyclo‑7,8‑dihydroguanosine-5́‑triphosphate (3,8‑cH2GTP), (ii) formation of cyclic pyranopterin monophosphate (cPMP) from the 3,8‑cH2GTP, (iii) conversion of cPMP into molybdopterin (MPT), (iv) insertion of molybdate into MPT to form Moco (human enzymes in parentheses). Molybdopterins are a class of cofactors found in most molybdenum-containing and all tungsten-containing enzymes. Synonyms for molybdopteri

Pralatrexate, sold under the brand name Folotyn, is a medication used for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL).

Biopterins are pterin derivatives which function as endogenous enzyme cofactors in many species of animals and in some bacteria and fungi. The prototypical compound of the class is biopterin (6-(1,2-dihydroxypropyl)-pterin), as shown in the infobox. Biopterins act as cofactors for aromatic amino acid hydroxylases (AAAH), which are involved in synthesizing a number of neurotransmitters including dopamine, norepinephrine, epinepherine, and serotonin, along with several trace amines. Nitric oxide synthesis also uses biopterin derivatives as cofactors. In humans, tetrahydrobiopterin (BH4) is the e

Tetrahydromethanopterin (THMPT, '''''') is a coenzyme in methanogenesis. It is the carrier of the C1 group as it is reduced to the methyl level, before transferring to the coenzyme M.

Xanthopterin is a yellow, crystalline solid that occurs mainly in the wings of butterflies and in the urine of mammals. Small microorganisms convert it into folic acid. It is the end product of a non-conjugated pteridine compound and inhibits the growth of lymphocytes produced by concanavalin. High levels of the chemical were found in patients with liver disease and hemolysis, the latter increasing levels by 35%.

Isoalloxazine is the structural foundation of flavins such as riboflavin (vitamin B2) and is a heterocyclic compound. It has a tricyclic structure which means it has three interconnected rings of atoms and is a tautomer of alloxazine. The structure is formed by primary-secondary aromatic o-diamines and they are a high-melting crystalline substance. The R-group is used to attach various flavin groups It has a similar structure to pteridines which has two interconnected rings. Isoalloxazine was first obtained in 1934 by Richard Kuhn an Austrian-German biochemist and lab mates. thumb|Isoalloxazin

Neopterin is an organic compound belonging to the pteridine class of heterocyclic compounds.

Sepiapterin, sold under the brand name Sephience, is a medication used for the treatment of hyperphenylalaninemia. Sepiapterin is a phenylalanine hydroxylase activator. It is also metabolite that is naturally synthesized in the human body.

phenoxy)-3-{(2E)-2-[3,3-dimethyl-5-sulfo-1-(4-sulfobutyl)-1,3-dihydro-2H-indol-2-ylidene]ethylidene}-1-cyclohexen-1-yl]vinyl}-3,3-dimethyl-1-(4-sulfobutyl)-3H-indolium-5-sulfonate | C=61 | H=67 | N=9 | O=17 | S=4 | SMILES = CC1(C2=C(C=CC(=C2)S(=O)(=O)[O-])[N+](=C1C=CC3=C(C(=CC=C4C(C5=C(N4CCCCS(=O)(=O)O)C=CC(=C5)S(=O)(=O)O)(C)C)CCC3)OC6=CC=C(C=C6)CC(C(=O)O)NC(=O)C7=CC=C(C=C7)NCC8=CN=C9C(=N8)C(=O)NC(=N9)N)CCCCS(=O)(=O)O)C | StdInChI = 1S/C61H67N9O17S4/c1-60(2)46-33-44(90(81,82)83)22-24-49(46)69(28-5-7-30-88(75,76)77)51(60)26-16-38-10-9-11-39(17-27-52-61(3,4)47-34-45(91(84,85)86)23-25-50(47)70(52

6,7-Dimethyl-8-ribityllumazine is a precursor for riboflavin. It is acted upon by riboflavin synthase.

2-Amino-4-hydroxy-6-pyrophosphoryl-methylpteridine (7,8-Dihydropterin pyrophosphate, dihydropterin-CH2OH-diphosphate) is a pteridine; a precursor to dihydrofolic acid.

chemical compound

Dyspropterin (6-pyruvoyltetrahydropterin, 6-PTHB) is an intermediate in tetrahydrobiopterin biosynthesis. It is the product of the enzyme 6-pyruvoyltetrahydropterin synthase and the substrate of two enzymes, 6-pyruvoyltetrahydropterin 2'-reductase and sepiapterin reductase.