Microanalysis of tryptophan metabolites in mice

Biochemical and clinical studies of a new case of alpha-aminoadipic aciduria

A mentally retarded, 10-year-old female with obesity, hypotonia, clumsiness and mild ocular abnormalities excreted in her urine large amounts of alpha-aminoadipic acid. Amino acid analyser studies and gas-liquid chromatography--mass spectrometry (GC--MS) confirmed the presence of alpha-aminoadipic acid in both urine and plasma but, in contrast to most other patients with this disorder, failed to demonstrate significant levels of alpha-ketoadipic acid in urine. Other known causes of alpha-aminoadipic aciduria were eliminated by showing that levels of lysine, saccharopine and pipecolic acid in plasma and urine were normal and that the activity of glutaryl-CoA dehydrogenase was also normal. Loading with L-lysine and L-tryptophan both increased the concentration of alpha-aminoadipic acid in blood and urine compatible with the primary deficiency of alpha-ketoadipate dehydrogenase, in spite of the absence of alpha-ketoadipic aciduria. Dietary restriction of lysine and administration of vitamins B1 and B6 were unsuccessful in correcting the biochemical abnormality.

The van urk-Salkowski reagent--a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives

The chromogenic reagent described has been tested with seventy-nine indole derivatives and found to be very sensitive and indole-specific. The lower limit of detection on silica gel thin-layer plates was between 25 and 50 ng for most indoles. Phenols and hydroxy-, and amino-benzoic acids, hydroxy-, and methoxy-cinnamic acids did not yield chromophores with the exception of p-amino-benzoic acid and p-hydroxy-cinnamic acid which gave yellow and pink chromophores at concentrations greater than 1 and 2 mug. Although many of the C-3 substituted indoles such as indole-3-acetic acid and tryptamine had colors in the reddish-violet-blue color region, most exhibited sufficient color differentiation to allow their identification by thin-layer chromatography. The procedure was simple and required only 10 min from the time of spraying the thin-layer plate until full color development was reached. The colors had a wide spectral range from yellow of the indole-3-glyoxylamide chromophore to blue of the melatonin chromophore, and were extremely stable.