Determination of the 8-methyl ether of xanthurenic acid in human serum by high-performance liquid chromatography with fluorescence detection.
We developed a simple and sensitive assay for the 8-methyl ether of xanthurenic acid in serum by high-performance liquid chromatography with fluorescence detection (excitation at 340 nm, emission at 450 nm). The compound under study in serum samples was extracted with Sep-Pak C18 cartridge and the extract was applied to an octadecylsilane-bonded column (Nucleosil 5C18, 150 x 4 mm I.D.). The mobile phase used was a mixture of 0.05 M sodium acetate buffer (pH 6.0), containing 5 mM sodium 1-octanesulfonate and 0.1 mM Na2EDTA, and acetonitrile (93:7, v/v). The 8-methyl ether of xanthurenic acid from serum samples was sufficiently separated to be clearly distinguishable. The quantification limit was 2 x 10(-14) mol, which was sensitive enough to detect 8-methyl ether of xanthurenic acid in serum from normal subjects. The method was applied to samples from patients with deficiency in tryptophan metabolism, xanthurenic acid/3-hydroxy kynurenineuria and showed a striking elevation in serum 8-methyl ether of xanthurenic acid.
Imai
J
J
Gifu Prefectural Health and Environment Research Center, Japan.
Yoshida
I
I
Murayama
K
K
Sakai
Y
Y
Shimizu
H
H
Sumi
T
T
Iguchi
T
T
Kawai
M
M
Yamaguchi
S
S
D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood* / Q000175:diagnosis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004987:Ethers; D006801:Humans; D007737:Kynurenine / Q000031:analogs & derivatives / Q000097:blood; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D014364:Tryptophan / Q000378:metabolism*; D014977:Xanthurenates / Q000097:blood*
D004987:Ethers; D014977:Xanthurenates; C026679:octadecylsilica; C005045:3-hydroxykynurenine; D007737:Kynurenine; C028330:xanthurenic acid; D012822:Silicon Dioxide; D014364:Tryptophan