n-ethylglycine and Bone-Neoplasms

A simple and highly sensitive HPLC for the determination of N-ethylglycine in urine was developed. The labeling reaction of N-ethylglycine with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride was carried out at 70 degrees C for 15 min at pH 9.0. The fluorescent derivative was separated on a reversed-phase column and detected at excitation and emission wavelengths of 320 and 400 nm, respectively. The detection limit of N-ethylglycine was 15 fmol (S/N = 3). The recovery of N-ethylglycine added to urine was 101.9%. The concentration of N-ethylglycine in urine of cancer patients with metastatic bone disease was 11.3 +/- 22.0 nmol/mg creatinine, and that of normal subject was 0.4 +/- 0.4 nmol/mg creatinine.

Topics: Adult; Bone Neoplasms; Case-Control Studies; Chromatography, High Pressure Liquid; Fluorescent Dyes; Humans; Hydrogen-Ion Concentration; Middle Aged; N-substituted Glycines; o-Phthalaldehyde; Phthalimides; Sensitivity and Specificity; Spectrometry, Fluorescence; Young Adult

Previously, a HPLC method for the determination of N-terminal prolyl dipeptides, proline and hydroxyproline in urine with fluorescence detection after pre-column derivatization with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride (DMS-Cl) [Inoue H, Iguchi H, Kono A, Tsuruta Y. Highly sensitive determination of N-terminal prolyl dipeptides, proline and hydroxyproline in urine by high-performance liquid chromatography using a new fluorescent labelling reagent, 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride. J Chromatogr 1999;724:221-230] was developed to study the relation between those analytes and bone diseases. When the urinary analytes were measured, a large peak due to an unknown substance was recognized in the chromatograms of cancer patients with metastatic bone disease, although it was scarcely present in normal subjects. In this study, we identified the unknown substance.. The fluorescent fraction based on the unknown substance was collected using HPLC and the structure of the fluorescence product was analyzed with MS, (1)H NMR and (13)C NMR.. The fluorescence product based on the unknown substance was established to be a DMS-derivative of N-ethylglycine.. Excretion of N-ethylglycine in the urine of cancer patients with metastatic bone disease is recognized, although N-ethylglycine is scarcely excreted in the urine of normal subjects.

Topics: Bone Neoplasms; Molecular Structure; N-substituted Glycines; Spectrometry, Fluorescence