2-Hydroxyphytanic acid

Wanders, R.J.A., van Roermund, C.W., Schor, D.S., ten Brink, H.J. Jakobs, C. Biochim. Biophys. Acta 1227, 177-182. 2-Hydroxyphytanic acid oxidase activity in rat and human hver and its deficiency in the Zellweger syndrome. 

PhyH activity in skin fibroblast homogenates was determined using a gas chromatography / mass spectrometry (GC-MS) method (Jansen et ai, manuscript in preparation). Briefly, skin fibroblasts were homogenised and incubated in the presence of all substrates and cofactors as described for human liver homogenates. The product of the PhyH reaction, 2-hydroxyphytanoyl-CoA was hydrolysed to form 2-hydroxyphytanic acid which was measured by stable isotope dilution GC-MS essentially as described by ten Brink et al ... 

Tsai, Su-Chen, Steinberg, D., Avigan, J., Fales, H. M. Studies on the stereospecificity of mitochondrial oxidation of phytanic acid and of a-hydroxyphytanic acid. J. Biol. Chem. 248, 1091-1097 (1973). 

Skjeldal, O.H. Stokke, O. (1988) Scand J. Clin. Lab. Invest. 48, 97-102. Evidence against a-hydroxyphytanic acid as an intermediate in the metabolism of phytanic acid. 

Cell culture studies " indicated that the primary biochemical defect in Refsum s disease lay in the conversion of phytanic acid to or-hydroxyphytanic acid, thus allowing accumulations of exogenously derived phytanic acid to occur. It therefore seems likely that Refsum s disease is due to a deficiency in phytanic acid cr-hydroxylase activity. In 1966 it was reported that dietary restriction of phytols and phytanates led to a fall in serum phytanic acid and some degree of clinical improvement. Malmendier et al in 1974 found that phytanic acid substituted for linoleic and arachidonic acids in the lipid sub-fractions of tissues from a patient with Refsum s disease. 

---