A. Niederwieser, S. K. Wadman, D. Danks
Dec 1, 1978
Citations
0
Influential Citations
23
Citations
Quality indicators
Journal
Clinica chimica acta; international journal of clinical chemistry
Abstract
Abstract Cis- and trans-4-hydroxycyclohexylacetic acid (4HCHAA) were identified in the urine of a child (suffering from transient tyrosinemia within the first year of life) and her mother, in addition to the recently described new sulfur amino acid (2-cystein-S-yl-1,4-dihydroxycyclohex-5-en-1-yl)acetic acid (hawkinsin, Haw). Identification was possible by gas chromatographic-mass spectrometric analysis of the methyl ester/trimethylsilyl ether and per-trimethylsilyl derivatives, and cochromatography with synthetic reference compounds. Oral loading tests with 3,5-bis-deutero- l -tyrosine have shown, using selected ion monitoring, that 4HCHAA and Haw are tyrosine metabolites. It is postulated that a defective 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27) exists and that Haw and 4HCHAA are derived from (1,2-epoxy-4-hydroxycyclohexa-3,5-dien-1-yl)acetic acid tautomerized to (1,2-epoxycyclohex-5-en-4-on-1-yl)acetic acid.