Kyotorphin
{{chembox
| Verifiedfields = changed
| verifiedrevid = 461936838
| Name = Kyotorphin
| ImageFile = Kyotorphin.png
| ImageSize = 200px
| ImageName = Chemical structure of kyotorphin
| IUPACName = (2S)-2-
| OtherNames = Kiotorphin
L-Tyrosyl-L-arginine
| Section1 = {{Chembox Identifiers
| PubChem = 123804
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 110353
| InChI = 1/C15H23N5O4/c16-11(8-9-3-5-10(21)6-4-9)13(22)20-12(14(23)24)2-1-7-19-15(17)18/h3-6,11-12,21H,1-2,7-8,16H2,(H,20,22)(H,23,24)(H4,17,18,19)/t11-,12-/m0/s1
| InChIKey = JXNRXNCCROJZFB-RYUDHWBXBC
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 273521
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C15H23N5O4/c16-11(8-9-3-5-10(21)6-4-9)13(22)20-12(14(23)24)2-1-7-19-15(17)18/h3-6,11-12,21H,1-2,7-8,16H2,(H,20,22)(H,23,24)(H4,17,18,19)/t11-,12-/m0/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = JXNRXNCCROJZFB-RYUDHWBXSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 70904-56-2
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 02N30CW3X0
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 17537
| SMILES = O=C(O)[C@@H](NC(=O)[C@@H](N)Cc1ccc(O)cc1)CCC/N=C(\N)N
}}
| Section2 = {{Chembox Properties
| C=15|H=23|N=5|O=4
| Density =
| MeltingPt =
| BoilingPt =
}}
}}
Kyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. It was first isolated from bovine brain, by Japanese scientists in 1979.{{cite journal |vauthors=Takagi H, Shiomi H, Ueda H, Amano H |title=A novel analgesic dipeptide from bovine brain is a possible Met-enkephalin releaser |journal=Nature |volume=282 |issue=5737 |pages=410–2 |date=November 1979 |pmid=228202 |doi= 10.1038/282410a0}} Kyotorphin was named for the site of its discovery, Kyoto, Japan and because of its morphine- (or endorphin-) like analgesic activity. Kyotorphin has an analgesic effect, but it does not interact with the opioid receptors. Instead, it acts by releasing met-enkephalin and stabilizing it from degradation. It may also possess properties of neuromediator/neuromodulator. It has been shown that kyotorphin is present in the human cerebrospinal fluid and that its concentration is lower in patients with persistent pain.{{cite journal |vauthors=Nishimura K, Kaya K, Hazato T, Ueda H, Satoh M, Takagi H |title=[Kyotorphin like substance in human cerebrospinal fluid of patients with persistent pain] |language=ja |journal=Masui |volume=40 |issue=11 |pages=1686–90 |date=November 1991 |pmid=1766121 }}