Figure 2
HPLC analysis of reference compounds. Chromatograms of mixtures of nucleobases, nucleosides and nucleotides separated by reversed-phase ion-pairing HPLC. A, chromatogram showing the separation of guanosine (1), inosine (2), IMP (3), GMP (4), adenosine (5), AMP (6), and ATP (7), detected at 260 nm. B, chromatogram showing the separation of 6MP (8), TX (9), MPrib (10), tIMP (11), TXrib (12), and tXMP (13), detected at 330 nm. *, peaks that were derived from the Hanks' balanced salt solution in which thiopurines were dissolved. UV absorbance is given in arbitrary units. The insets show examples of absorbance spectra of indicated peaks, which were used to identify different metabolites.