A new and rapid method for the determination of the excitotoxic tryptophan metabolite quinolinic acid is based on its enzymatic conversion to nicotinic acid mononucleotide and, in a second step utilizing ['H]ATP, further to ['HI deamido-NAD. Specificity of the assay is assured by using a highly puri
A new fluorometric assay method for quinolinic acid
β Scribed by Hiroshi Taguchi; Shiro Koyama; Yoshihide Shimabayashi; Kazuo Iwai
- Publisher
- Elsevier Science
- Year
- 1983
- Tongue
- English
- Weight
- 336 KB
- Volume
- 131
- Category
- Article
- ISSN
- 0003-2697
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β¦ Synopsis
A new fluorometric assay method for quinolinic acid is introduced in this study. Quinolinic acid-hydrazine complex, a stable fluorescent compound, is formed after heating quinolinic acid with hydrazine at 215-220Β°C for 2 min. Fluorescence excitation and emission maxima of the complex are at 285 and 380 nm, respectively. This assay method is rapid and rather sensitive. It takes about 30 min to ascertain the amount of quinolinic acid as low as 50 ng. Specificity of this method is high among biological compounds. An ultrasensitive assay method for quinolinic acid (as low as 20 pg) with diphenylhydrazine instead of hydrazine is also found. After separating the quinolinic acid-diphenylhydrazine complex from residual diphenylhydrazine, this ultrasensitive assay method may be practically applicable.
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