Zaprinast

{{chembox | Verifiedfields = changed | verifiedrevid = 470635612 | ImageFile = Zaprinast.svg | ImageClass = skin-invert-image | ImageSize = 150 | ImageAlt = | IUPACName = 5-(2-Propoxyphenyl)-1''H''-[1,2,3]triazolo[4,5-d]pyrimidin-7(4''H'')-one | OtherNames = M&B 22,948

| Section1 = {{Chembox Identifiers | IUPHAR_ligand = 2919 | CASNo = 37762-06-4 | CASNo_Ref = {{cascite|changed|??}} | PubChem = 135399235 | ChEBI = 92215 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 5520 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 28079 | EINECS = 253-655-1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = REZGGXNDEMKIQB-UHFFFAOYSA-N | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI=1S/C13H13N5O2/c1-2-7-20-9-6-4-3-5-8(9)11-14-12-10(13(19)15-11)16-18-17-12/h3-6H,2,7H2,1H3,(H2,14,15,16,17,18,19) | SMILES = O=C1C2=C(N=NN2)NC(C3=CC=CC=C3OCCC)=N1 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = GXT25D5DS0 }}

| Section2 = {{Chembox Properties | C=13 | H=13 | N=5 | O=2 | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = }}

| Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }}

| Section5 = {{Chembox Pharmacology | AdminRoutes = | Bioavail = | Metabolism = | HalfLife = | ProteinBound = | Excretion = | Legal_status = | Legal_US = | Legal_UK = | Legal_AU = | Legal_CA = | PregCat = | PregCat_AU = | PregCat_US = }} }}

'''Zaprinast''' was an unsuccessful clinical drug candidate that was a precursor to the chemically related PDE5 inhibitors, such as sildenafil (Viagra), which successfully reached the market. It is a phosphodiesterase inhibitor,<ref>{{cite journal | last1 = Choi | first1 = SH | last2 = Choi | first2 = DH | last3 = Song | first3 = KS | last4 = Shin | first4 = KH | last5 = Chun | first5 = BG | title = Zaprinast, an inhibitor of cGMP-selective phosphodiesterases, enhances the secretion of TNF-alpha and IL-1beta and the expression of iNOS and MHC class II molecules in rat microglial cells | journal = Journal of Neuroscience Research | volume = 67 | issue = 3 | pages = 411–21 | year = 2002 | pmid = 11813247 | doi = 10.1002/jnr.10102 | s2cid = 24513289 }}</ref> selective for the subtypes PDE5, PDE6, PDE9 and PDE11. IC50 values are 0.76, 0.15, 29.0, and 12.0 ''μ''M, respectively.<ref>{{Cite journal | last1 = Taniguchi | first1 = Y. | last2 = Tonaikachi | first2 = H. | last3 = Shinjo | first3 = K. | doi = 10.1016/j.febslet.2006.08.015 | title = Zaprinast, a well-known cyclic guanosine monophosphate-specific phosphodiesterase inhibitor, is an agonist for GPR35 | journal = FEBS Letters | volume = 580 | issue = 21 | pages = 5003–5008 | year = 2006 | pmid = 16934253 | pmc = | bibcode = 2006FEBSL.580.5003T | s2cid = 43142927 }}</ref><ref>{{Cite journal | last1 = Keswani | first1 = A. N. | last2 = Peyton | first2 = K. J. | last3 = Durante | first3 = W. | last4 = Schafer | first4 = A. I. | last5 = Tulis | first5 = D. A. | title = The Cyclic GMP Modulators YC-1 and Zaprinast Reduce Vessel Remodeling Through Antiproliferative and Proapoptotic Effects | doi = 10.1177/1074248409333266 | journal = Journal of Cardiovascular Pharmacology and Therapeutics | volume = 14 | issue = 2 | pages = 116–124 | year = 2009 | pmid = 19342499 | pmc =2702762 }}</ref>

Zaprinast inhibits the growth of asexual blood-stage malaria parasites (''P. falciparum'') ''in vitro'' with an ED50 value of 35 ''μ''M, and inhibits PfPDE1, a ''P. falciparum'' cGMP-specific phosphodiesterase, with an IC50 value of 3.8 ''μ''M.<ref>{{Cite journal|title = PfPDE1, a novel cGMP-specific phosphodiesterase from the human malaria parasite Plasmodium falciparum|author1=Keizo Yuasa |author2=Fumika Mi-Ichi |author3=Tamaki Kobayashi |author4=Masaya Yamanouchi |author5=Jun Kotera |author6=Kiyoshi Kita |author7=Kenji Omori |date = 2005|journal = Biochem. J.|doi = 10.1042/BJ20050425|pmid = 16038615|pmc=1317681|volume=392|issue=Pt 1 |pages=221–9}}</ref>

Zaprinast has also been shown to activate the orphan G-protein coupled receptor known as GPR35, both in rats and humans,<ref>{{cite journal|journal = FEBS Letters|title = Zaprinast, a well-known cyclic guanosine monophosphate-specific phosphodiesterase inhibitor, is an agonist for GPR35|author1=Yasuhito Taniguchi |author2=Hiroko Tonai-Kachi |author3=Katsuhiro Shinjo |volume = 580|issue = 21|pages = 5003–5008|year = 2006|doi=10.1016/j.febslet.2006.08.015|pmid=16934253| bibcode=2006FEBSL.580.5003T |s2cid = 43142927}}</ref> and to inhibit the mitochondrial pyruvate carrier.<ref>{{cite journal|journal = J Biol Chem|title = Inhibition of mitochondrial pyruvate transport by zaprinast causes massive accumulation of aspartate at the expense of glutamate in the retina|author1=Jianhai Du |author2=Whitney M Cleghorn |author3=Laura Contreras |author4=Ken Lindsay |author5=Austin M Rountree |author6=Andrei O Chertov |author7=Sally J Turner |author8=Ayse Sahaboglu |author9=Jonathan Linton |author10=Martin Sadilek |author11=Jorgina Satrustegui |author12=Ian R Sweet |author13=Francois Paquet-Durand |author14=James B Hurley |volume = 288|issue = 50|pages = 36129–36140|year = 2013|doi=10.1074/jbc.M113.507285|pmid=24187136|s2cid = 9429684|pmc=3861660 |doi-access = free}}</ref>

==References== {{reflist}}

Category:Abandoned drugs Category:Phosphodiesterase inhibitors Category:PDE5 inhibitors Category:Propoxy compounds Category:Triazolopyrimidines Category:Lactams