P. Jones, S. Tjoa, P. Fennessey
2002
Citations
0
Influential Citations
11
Citations
Journal
Clinical chemistry
Abstract
Mitochondrial fatty acid oxidation (FAO) is a catabolic pathway that supplies energy for the normal physiologic functioning of many tissues when glucose is unavailable, and it also supplies energy for some tissues even when glucose is available (1)(2). The FAO pathway is complex and not fully understood. Quantitative measurement of the concentrations of 3-hydroxy-fatty acids (3-OHFAs) in plasma or serum samples from individuals who are suspected of having a deficiency in FAO, especially in the enzyme step involving the l-3-hydroxyacyl-CoA-dehydrogenases, is a useful tool to aid in diagnosis (3)(4). This study adds the quantitative measurement of 3-hydroxy-octadecanoic acid (3-OH-C18) to the previously reported assay (4) that measures the six shorter chain-length FAO intermediates, 3-hydroxy-hexanoic acid (3-OH-C6), 3-hydroxy-octanoic acid (3-OH-C8), 3-hydroxy-decanoic acid (3-OH-C10), 3-hydroxy-dodecanoic (3-OH-C12), 3-hydroxy-tetradecanoic acid (3-OH-C14), and 3-hydroxy-hexadecanoic acid (3-OH-C16). 3-OH-C18 was synthesized by the method of Jones et al. (4), with the following changes. The precursor for 3-OH-C18 was not2commercially available; thus the 3-OH-C18 precursor, hexadecanal, was synthesized first by the method of Landini et al. (5). A saturated solution of potassium chromate (0.55 mol/L) in 300 mL/L aqueous sulfuric acid was reacted with 0.01 mol of 1-hexadecanal dissolved in 60 mL of methylene chloride in the presence of 0.001 mol of tetrabutylammonium hydrogen sulfate as a catalyst (ratio of 1-hexadecanol to catalyst, 10:1). The unlabeled and [1,2]-13C2-labeled 3-OH-C18 were then synthesized from the hexadecanal as described previously (4). The methylene chloride, 1-hexadecanol, and tetrabutylammonium hydrogen sulfate were obtained from Aldrich Chemical Co. Analysis of the naturally occurring and stable-isotope 3-OH-C18s after synthesis was also performed as described previously (4). This analysis demonstrated that the naturally occurring 3-OH-C18 was 89% pure with the expected composition, and the stable-isotope 3-OH-C18 was 95% pure with the expected composition. Mass spectra revealed …