KINETICS STUDY OF THE BIOTRANSFORMATION OF AN OLIGONUCLEOTIDE PRODRUG IN CELLS EXTRACT BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME-OF-FLIGHT MASS SPECTROMETRY

Abstract

The fate of a dodecathymidine prodrug in cell extract was monitored by MALDI-TOF MS. This technique allows a facile identification and a relative quantification of metabolites produced. We showed that the relative peak intensities were similar to the relative metabolite proportions that permitted the determination of their half-lives. The oligonucleotide prodrug was fully metabolized to yield the T12 phosphorothioate likely through a carboxyesterase mediated mechanism.