:Pipecolic acid
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 445012529
| ImageFile = Structural formula of pipecolic acid.svg
| ImageSize = 216px
| PIN = Piperidine-2-carboxylic acid
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 3105-95-1
| CASNo_Comment = (2S)
| CASNoOther =
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 69374CKB33
| PubChem = 849
| KEGG_Ref = {{keggcite|changed|kegg}}
| KEGG = C00408
| SMILES = C1CCNC(C1)C(=O)O
| EINECS = 217-024-4
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 826
| InChI = 1/C6H11NO2/c8-6(9)5-3-1-2-4-7-5/h5,7H,1-4H2,(H,8,9)
| InChIKey = HXEACLLIILLPRG-UHFFFAOYAL
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C6H11NO2/c8-6(9)5-3-1-2-4-7-5/h5,7H,1-4H2,(H,8,9)
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = HXEACLLIILLPRG-UHFFFAOYSA-N
| RTECS =
| MeSHName = C031345
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 17964
}}
|Section2={{Chembox Properties
| Formula = C6H11NO2
| MolarMass = 129.15704
| Appearance = white or colorless solid
| Density =
| MeltingPtC = 268
| BoilingPt =
| Solubility =
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
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}}
Pipecolic acid (piperidine-2-carboxylic acid) is an organic compound with the formula HNC5H9CO2H. It is a carboxylic acid derivative of piperidine and, as such, an amino acid, although not one encoded genetically. Like many other α-amino acids, pipecolic acid is chiral, although the S-stereoisomer is more common. It is a colorless solid.
Its biosynthesis starts from lysine.{{cite journal |doi=10.1021/ja0587603|title=Biosynthesis of Pipecolic Acid by RapL, a Lysine Cyclodeaminase Encoded in the Rapamycin Gene Cluster|year=2006|last1=Gatto|first1=Gregory J.|last2=Boyne|first2=Michael T.|last3=Kelleher|first3=Neil L.|last4=Walsh|first4=Christopher T.|journal=Journal of the American Chemical Society|volume=128|issue=11|pages=3838–3847|pmid=16536560|bibcode=2006JAChS.128.3838G }} CRYM, a taxon-specific protein that also binds thyroid hormones, is involved in the pipecolic acid pathway.
Medicine
It accumulates in pipecolic acidemia. Elevation of pipecolic acid can be associated with some forms of epilepsy, such as pyridoxine-dependent epilepsy.{{cite journal |vauthors=Plecko B, Hikel C, Korenke GC, etal |title=Pipecolic acid as a diagnostic marker of pyridoxine-dependent epilepsy |journal=Neuropediatrics |volume=36 |issue=3 |pages=200–5 |year=2005 |pmid=15944906 |doi=10.1055/s-2005-865727}}{{cite journal | vauthors = Kaminiów K, Pająk M, Pająk R, Paprocka J | title = Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency Resulting in Neonatal-Onset Refractory Seizures | journal = Brain Sciences | volume = 12 | issue = 1 | date = December 2021 | page = 65 | pmid = 35053812 | pmc = 8773593 | doi = 10.3390/brainsci12010065 | url = | doi-access = free }}
Occurrence and reactions
Like most amino acids, pipecolic acid is a chelating agent. One complex is Cu(HNC5H9CO2)2(H2O)2.{{cite journal |doi=10.1016/0957-4166(95)00400-9|title=Convenient resolution of (±)-piperidine-2-carboxylic acid ((±)-pipecolic acid) by separation of palladium(II) diastereomers containing orthometallated (S)-(−)-1-[1-(dimethylamino)ethyl]naphthalene|year=1995|last1=Hockless|first1=David C.R.|last2=Mayadunne|first2=Renuka C.|last3=Wild|first3=S.Bruce|journal=Tetrahedron: Asymmetry|volume=6|issue=12|pages=3031–3037}}
Pipecolic acid was identified in the Murchison meteorite.{{cite journal |last1= Kvenholden |first1= Keith A. |last2= Lawless |first2= James G. |last3= Ponnamperuma |first3 = Cyril |date=February 1971 |title= Nonprotein Amino Acids in the Murchison Meteorite |journal= Proceedings of the National Academy of Sciences |volume= 68 |issue= 2 |pages= 486–490 | doi = 10.1073/pnas.68.2.486 |pmc= 388966 |pmid=16591908|bibcode= 1971PNAS...68..486K |doi-access= free }}
It also occurs in the leaves of the genus Myroxylon, a tree from South America.{{cite journal | last1 = Kite | first1 = GC | last2 = Cardoso | first2 = D | last3 = Lewis | first3 = GP | last4 = Zartman | first4 = CE | last5 = de Queiroz | first5 = LP | last6 = Veitch | first6 = NC | year = 2015 | title = Monomethyl ethers of 4,5-dihydroxypipecolic acid from Petaladenium urceoliferum: Enigmatic chemistry of an enigmatic legume | journal = Phytochemistry | volume = 116 | pages = 198–202 | doi = 10.1016/j.phytochem.2015.02.026 | pmid = 25817832| bibcode = 2015PChem.116..198K }}