Identification of the stereoisomeric configurations of methylcitric acid produced by si-citrate synthase and methylcitrate synthase using capillary gas chromatography-mass spectrometry.

The absolute separation of the four stereoisomeric configurations of methylcitric acid can be achieved on a nonchiral stationary phase SE30 capillary column using the corresponding O-acetylated (tri-(-)-2-butyl ester derivatives. Identification of the separated isomers was done using methylcitric acid produced by si-citrate synthase and methylcitrate synthase of Candida lipolitica. si-Citrate synthase produces the (2S,3S)-, (2S,3R)- and a small amount of the (2R,3S)-isomers.

Diagnosis of mitochondrial fatty acid oxidation defects.

Inherited defects of mitochondrial beta-oxidation of fatty acids lead to hypoketotic hypoglycemia during prolonged fasting. Affected patients may present with episodes of a Reye-like illness or even sudden child death. The number of currently detected patients with medium-chain acyl-CoA dehydrogenase deficiency--the most common disease in this area--is indicative of a high frequency, possibly comparable to that of phenylketonuria.

Diagnosis of medium-chain acyl-CoA dehydrogenase deficiency in lymphocytes and liver by a gas chromatographic method: the effect of oral riboflavin supplementation.

The activity of medium-chain acyl-CoA dehydrogenase (MCAD) with octanoyl-CoA as a substrate was measured in human lymphocytes by a gas chromatographic technique. Phenazine methosulfate was used as the primary electron acceptor. After the addition of crotonase and subsequent hydrolysis, the reaction product 3-hydroxyoctanoic acid was quantitated by capillary gas-liquid chromatography of the trimethylsilyl derivatives.

Gas chromatography method for the separation of amino acids enantiomers in plasma and urine. Application in a case of short bowel syndrome.

Urinary amino acids were isolated from the urine of healthy controls and a patient with a short bowel syndrome. Following derivatization with isopropyl alcohol/HCl and trifluoroacetic anhydride the amino acid enantiomers were separated by gas chromatography on a Chirasil-L-Val column. All subjects excreted D-alanine (10-30% of total Ala).

Medium- and long-chain 3-hydroxymonocarboxylic acids: analysis by gas chromatography combined with mass spectrometry.

Medium- and long-chain 3-hydroxymonocarboxylic acids represent intermediates in the beta-oxidation of fatty acids: they accumulate in the plasma of patients with an inherited deficiency of long-chain 3-hydroxyacylcoenzyme A dehydrogenase. 3-Hydroxy acids with chain lengths varying from 6 to 16 were synthesized by a Reformatzky reaction. Capillary gas chromatography of the pertrimethylsilyl derivatives was performed on a CP-Sil 19 CB column, coupled to a quadrupole mass spectrometer in the electron impact mode.