Chemistry:Mercapturic acid
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Mercapturic acids are condensation products formed from the coupling of cysteine with aromatic compounds.[1] They are formed as conjugates in the liver and are excreted in the urine.[1][2]
Mercapturic acids are formed as part of xenobiotic metabolism. A glutathione S-transferase first conjugates the foreign compound to glutathione, forming an adduct. The adduct is then converted to the mercapturic acid: the γ-glutamate and glycine residues in the glutathione molecule are removed by gamma-glutamyl transpeptidase and dipeptidases. In the final step, the cystine residue in the conjugate is acetylated. The mercapturic acid is then excreted.[3]
Levels of mercapturic acids in urine may be used as an indicator of exposure to, e.g., ethylene dibromide,[4] acrylamide, and terbuthylazine.[5]
Etymology
The name mercapturic acid is a combination of mercapturic and acid. The latter indicates that the compound is an acid. The former is a compound word consisting of the stem mercaptur-, coming from mercaptan, and the suffix -ic, meaning "having the character of". In sum, the name mercapturic acid means "an acid with mercaptan character/nature".[6]
References
- ↑ 1.0 1.1 medical-dictionary.thefreedictionary.com Retrieved on June 25, 2009
- ↑ Hanna, Patrick E.; Anders, M. W. (26 November 2019). "The mercapturic acid pathway". Critical Reviews in Toxicology 49 (10): 819–929. doi:10.1080/10408444.2019.1692191.
- ↑ The Role of Glutathione and Glutathione S-Transferases in Mercapturic Acid Biosynthesis. Advances in Enzymology and Related Areas of Molecular Biology. 32. 1969. pp. 173–219. doi:10.1002/9780470122778.ch5. ISBN 978-0-470-64961-9.
- ↑ "Excretion of the mercapturic acid S-[2-(N7-guanyl)ethyl]-N-acetylcysteine in urine following administration of ethylene dibromide to rats". Cancer Res. 49 (21): 5843–7. November 1989. PMID 2790795.
- ↑ "Determination of terbuthylazine and desethylterbuthylazine in human urine and hair samples by eletrospray ionization-liquid chromatography/triple quadrupole mass spectrometry". Analytical and Bioanalytical Chemistry 404 (3): 875–86. July 2012. doi:10.1007/s00216-012-6184-3. PMID 22752446.
- ↑ "Definition of IC" (in en). 2024-03-26. https://www.merriam-webster.com/dictionary/IC.
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