Analytic techniques in the separation and identification of specific purine and pyrimidine degradation products of tRNA: Application to urine samples from cancer patients

High-resolution liquid chromatographic procedures for the separation and analysis of several nucleosides and purine bases were applied to the separation of trace urinary degradation products of tRNA in humans and their subsequent identification by means of gas chromatography (GC), mass spectrometry (MS), and combined GC-MS. Purine and pyrimidine products present in all urine samples included pseudouridine (ψrd), 1-methylinosine (m¹l), N², N²-dimethylguanosine ((Equation Presented)G), 1-methylguanosine (m¹G), and 7-methylguanine (7-MeGua). The excretion of these compounds in the urine of normal control adults were, in mg/kg/24 hours: ψrd, 0.94; m¹l, 0.06; (Equation Presented), 0.06; m¹G, 0.07; and 7-MeGua, 0.10. Clinically normal children from 4 to 13 years old excreted about 60% more of these compounds than did the adult controls. Adult patients with neoplastic diseases, including lung cancer, leukemia, Burkitt’s lymphoma, melanoma, and ovarian cancer, showed elevated urinary excretion of ψrd, m¹l, and m¹l, 0.06; m²₂. Results of a few analyses for m¹G and 7-MeGua generally seemed to parallel those of the other methylated compounds.