Pipecolic acid explained

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.^[1] 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.^{[2] [3]}

Occurrence and reactions

Like most amino acids, pipecolic acid is a chelating agent. One complex is Cu(HNC₅H₉CO₂)₂(H₂O)₂.^[4]

Pipecolic acid was identified in the Murchison meteorite.^[5] It also occurs in the leaves of the genus Myroxylon, a tree from South America.^[6]

See also

• Bupivacaine
• Efrapeptin

Notes and References

1. 10.1021/ja0587603. Biosynthesis of Pipecolic Acid by RapL, a Lysine Cyclodeaminase Encoded in the Rapamycin Gene Cluster. 2006. Gatto. Gregory J.. Boyne. Michael T.. Kelleher. Neil L.. Walsh. Christopher T.. Journal of the American Chemical Society. 128. 11. 3838–3847. 16536560.
2. Plecko B, Hikel C, Korenke GC, etal . Pipecolic acid as a diagnostic marker of pyridoxine-dependent epilepsy . Neuropediatrics . 36 . 3 . 200–5 . 2005 . 15944906 . 10.1055/s-2005-865727.
3. Kaminiów K, Pająk M, Pająk R, Paprocka J . Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency Resulting in Neonatal-Onset Refractory Seizures . Brain Sciences . 12 . 1 . December 2021 . 65 . 35053812 . 8773593 . 10.3390/brainsci12010065 . free .
4. 10.1016/0957-4166(95)00400-9. Convenient resolution of (±)-piperidine-2-carboxylic acid ((±)-pipecolic acid) by separation of palladium(II) diastereomers containing orthometallated (S)-(−)-1-[1-(dimethylamino)ethyl]naphthalene. 1995. Hockless. David C.R.. Mayadunne. Renuka C.. Wild. S.Bruce. Tetrahedron: Asymmetry. 6. 12. 3031–3037.
5. Kvenholden . Keith A. . Lawless . James G. . Ponnamperuma . Cyril . February 1971 . Nonprotein Amino Acids in the Murchison Meteorite . Proceedings of the National Academy of Sciences . 68 . 2 . 486–490 . 10.1073/pnas.68.2.486 . 388966 . 16591908. 1971PNAS...68..486K . free .
6. Kite . GC . Cardoso . D . Lewis . GP . Zartman . CE . de Queiroz . LP . Veitch . NC . 2015 . Monomethyl ethers of 4,5-dihydroxypipecolic acid from Petaladenium urceoliferum: Enigmatic chemistry of an enigmatic legume . Phytochemistry . 116 . 198–202 . 10.1016/j.phytochem.2015.02.026 . 25817832. 2015PChem.116..198K .