8-hydroxyguanosine and 5-hydroxyuridine

Three hydroxyribonucleosides catalyzing the oxido-reduction of NADH and K3F3(CN)6 were purified from Torula yeast RNA by a series of steps including sodium dodecyl sulfate/phenol extraction, nuclease P1 digestion, alkaline phosphatase digestion, anion-exchange chromatography, and high performance liquid chromatography on an ODS column. Analysis by fast atom bombardment-mass spectrometry and 1H and 13C NMR spectroscopy led to identification of the redox ribonucleosides as 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine. Their mass spectra, chromatographic behavior, UV spectra, NMR spectra, and IR spectra were identical to those from natural and synthetic sources. Oxidoreduction activities were specific for K3Fe(CN)6 as the oxidant and NADH as the reductant; and their magnitudes decreased in the order 5-hydroxycytidine, 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine. The fact that these nucleosides have redox activities suggests new functional roles for RNAs as catalysts.

Topics: Adenosine; Alkaline Phosphatase; Chromatography, Ion Exchange; Cryptococcus; Dihydrolipoamide Dehydrogenase; Guanosine; Kinetics; Oxidation-Reduction; Ribonucleosides; RNA, Fungal; Spectrum Analysis; Uridine

Three nucleosides catalyzing the oxidoreduction of NADH and K3Fe(CN)6 were isolated from Torula yeast RNA and also obtained by a series of steps: SDS-phenol extraction, nuclease P1 digestion, alkaline phosphatase digestion, anion exchange chromatography, and HPLC on an ODS column. Their chemical structures were clearly determined as 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine from the results of FAB-MS, 1H and 13C-NMR spectroscopies.

Topics: Adenosine; Cryptococcus; Guanosine; Oxidation-Reduction; RNA, Catalytic; RNA, Fungal; Uridine