3-hydroxydecanedioic acid and related homologues: urinary metabolites in ketoacidosis.

Urine from patients with ketoacidosis was found to contain a number of aliphatic 3-hydroxy dicarboxylic acids. The acids were purified by silicic acid chromatography and their structures determined by gas chromatography-mass spectrometry of different derivatives. The major compound was 3-hydroxydecanedioic acid. Minor compounds were 3-hydroxyoctanedioic acid, 3-hydroxyoctenedioic acid, 3-hydroxydecenedioic acid, 3-hydroxydodecanedioic acid, 3-hydroxydodecenedioic acid, 3-hydroxytetradecenedioic acid, and 3-hydroxytetradecadienedioic acid. The excretion of 3-hydroxydecanedioic acid correlated positively with the excretion of hexanedioic acid, another metabolite constantly found in ketoacidosis (Pettersen et al., Clin. Chim. Acta 38: 17-24, 1972). We suggest that the 3-hydroxy dicarboxylic acids are formed from fatty acids by a combination of omega-oxidation and incomplete beta-oxidation.