Hibiya M, Teradaira R, Shimpo K, Matsui T, Sugimoto T, Nagatsu T
Institute for Comprehensive Medical Science, School of Medicine, Fujita Health University, Aichi, Japan.
J Chromatogr B Biomed Sci Appl. 1997 Mar 28;691(1):223-7. doi: 10.1016/s0378-4347(96)00417-3.
We previously reported a HPLC assay method using fluorimetric detection for the simultaneous determination of urinary N2-(3-aminopropyl)biopterin (oncopterin, a natural pteridine newly found in urine from cancer patients), biopterin and neopterin. We now have observed that an unknown substance, which may be derived from methotrexate, in urine from a patient with stomach cancer interfered with the assay of oncopterin and demonstrated that oncopterin could be completely separated from the unidentified substance by HPLC using a Nucleosil 100-5SA strong cation-exchange column. Furthermore, oncopterin was not detectable by this HPLC-fluorimetric method in urine samples from patients with stomach cancer who were not treated with methotrexate. The content of urinary oncopterin from cancer patients is supposed to be very low, with less than 1 mumol/mol creatinine. The present results indicate that the peak found with elution from the C18 column was a methotrexate-derived compound and co-eluted with the analyte oncopterin.
我们之前报道了一种采用荧光检测的高效液相色谱法，用于同时测定尿中的N2-(3-氨丙基)生物蝶呤（癌蝶呤，一种新发现于癌症患者尿液中的天然蝶啶）、生物蝶呤和新蝶呤。我们现在观察到，一名胃癌患者尿液中一种可能源自甲氨蝶呤的未知物质干扰了癌蝶呤的测定，并证明使用Nucleosil 100-5SA强阳离子交换柱通过高效液相色谱法可将癌蝶呤与该未知物质完全分离。此外，在未接受甲氨蝶呤治疗的胃癌患者尿液样本中，通过这种高效液相色谱-荧光法检测不到癌蝶呤。癌症患者尿中癌蝶呤的含量应该非常低，每摩尔肌酐低于1微摩尔。目前的结果表明，从C18柱洗脱时发现的峰是一种源自甲氨蝶呤的化合物，与分析物癌蝶呤共洗脱。
