Reversed-phase high-performance liquid chromatographic separation of diastereomeric phosphorothioate analogues of oligodeoxyribonucleotides and other backbone-modified congeners of DNA.

Diastereomeric phosphorothioate analogues of oligodeoxyribonucleotides, which were synthesized by an automated, solid-phase, phosphoramidite-coupling method, were conveniently separated by reversed-phase high-performance liquid chromatography on a muBondapak C18 column with a gradient of acetonitrile in triethylammonium acetate buffer. These synthetic and chromatographic methods were also used to obtain diastereomerically pure bis-phosphorothioate, alkanephosphonate, and O-alkyl phosphotriester analogues of DNA for exploratory studies of stereochemistry and phosphorolytic enzymes.