:7-Nitroindazole

{{chembox

| Verifiedfields = changed

| verifiedrevid = 477226776

| ImageFile = 7-Nitroindazole.svg

| ImageSize = 150

| PIN = 7-Nitro-1H-indazole

| OtherNames =

|Section1={{Chembox Identifiers

| IUPHAR_ligand = 5127

| InChI = 1/C7H5N3O2/c11-10(12)6-3-1-2-5-4-8-9-7(5)6/h1-4H,(H,8,9)

| InChIKey = PQCAUHUKTBHUSA-UHFFFAOYAE

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 247378

| ChEBI = 40287

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C7H5N3O2/c11-10(12)6-3-1-2-5-4-8-9-7(5)6/h1-4H,(H,8,9)

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = PQCAUHUKTBHUSA-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo=2942-42-9

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = UX0N37CMVH

| PubChem=1893

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 1821

| SMILES = [O-][N+](=O)c1cccc2c1[nH]nc2

}}

|Section2={{Chembox Properties

| Formula=C₇H₅N₃O₂

| MolarMass=163.1335

| Appearance=

| Density=

| MeltingPt=

| BoilingPt=

| Solubility=

}}

|Section3={{Chembox Hazards

| MainHazards=

| FlashPt=

| AutoignitionPt =

}}

}}

7-Nitroindazole, or 7-NI, is a heterocyclic small molecule containing an indazole ring that has been nitrated at the 7 position. Nitroindazole acts as a selective inhibitor for neuronal nitric oxide synthase, a hemoprotein enzyme that, in neuronal tissue, converts arginine to citrulline and nitric oxide (NO).{{cite journal |author =Southan GJ |author2 = Szabó C |title=Selective pharmacological inhibition of distinct nitric oxide synthase isoforms |journal=Biochem. Pharmacol. |volume=51 |issue=4 |pages=383–94 |date=February 1996 |pmid=8619882 |doi=10.1016/0006-2952(95)02099-3}} Nitric oxide can diffuse through the plasma membrane into neighbouring cells, allowing cell signalling, so nitroindazole indirectly inhibits this signalling process.{{cite journal | author = Moore PK | author2 = Wallace P | author3 = Gaffen Z | author4 = Hart SL | author5 = Babbedge RC | title = Characterization of the novel nitric oxide synthase inhibitor 7-nitro indazole and related indazoles: antinociceptive and cardiovascular effects | journal = Br. J. Pharmacol. | volume = 110 | issue = 1 | pages = 219–24 |date=September 1993 | pmid = 7693278 | doi = 10.1111/j.1476-5381.1993.tb13795.x| pmc = 2175981 }}{{cite journal | author = Babbedge RC | author2 = Bland-Ward PA | author3 = Hart SL | author4 = Moore PK | title = Inhibition of rat cerebellar nitric oxide synthase by 7-nitro indazole and related substituted indazoles | journal = Br. J. Pharmacol. | volume = 110 | issue = 1 | pages = 225–8 |date=September 1993 | pmid = 7693279 | doi = 10.1111/j.1476-5381.1993.tb13796.x| pmc = 2175991 }}{{cite journal | author = Moore PK | author2 = Babbedge RC | author3 = Wallace P | author4 = Gaffen ZA | author5 = Hart SL | title = 7-Nitro indazole, an inhibitor of nitric oxide synthase, exhibits anti-nociceptive activity in the mouse without increasing blood pressure | journal = Br. J. Pharmacol. | volume = 108 | issue = 2 | pages = 296–7 |date=February 1993 | pmid = 7680591 | doi = 10.1111/j.1476-5381.1993.tb12798.x| pmc = 1907983 }} Other inhibitors exist such as 3-bromo-7-nitroindazole, which is more potent but less specific,{{cite journal | author = Gammie SC | author2 = Olaghere-da Silva UB | author3 = Nelson RJ | title = 3-bromo-7-nitroindazole, a neuronal nitric oxide synthase inhibitor, impairs maternal aggression and citrulline immunoreactivity in prairie voles | journal = Brain Res. | volume = 870 | issue = 1–2 | pages = 80–6 |date=July 2000 | pmid = 10869504 | doi = 10.1016/S0006-8993(00)02404-5| s2cid = 23918529 }} or N-propyl-L-arginine (NPA), which acts on a different site.{{cite journal | author = Kampf C | author2 = Roomans GM | title = Effects of hypochlorite on cultured respiratory epithelial cells | journal = Free Radic. Res. | volume = 34 | issue = 5 | pages = 499–511 |date=May 2001 | pmid = 11378533 | doi = 10.1080/10715760100300441| s2cid = 5920036 }}