Capillary electrophoretic study of carboplatin and analogues with nucleoside monophosphates, di- and trinucleotides

Carboplatin (cis-diammine-1,1-cyclobutane-dicarboxylatoplatinum(II)) is the only cisplatin (cis-diammine-dichloroplatinum(II)) derivative currently available for the treatment of cancer worldwide. The higher stability of the carboxylate ligand compared to the coordinated chloride in cisplatin results in a reduced reactivity of the molecule. Capillary electrophoresis has been applied for investigating the adduct formation of carboplatin and analogues with nucleoside monophosphates, di- and trinucleotides. Adduct formation results in a significant shift of the absorption maximum to lower energy compared to free nucleotides. Therefore, characterization of the analytes was performed by UV additionally to NMR spectroscopy. A preference for GMP- and AMP-coordination was found. The ability of separating all four common nucleotides and their major platinum adducts in a single run demonstrates the suitability of CE for this kind of investigations.