SYNTHESIS AND CHARACTERIZATION OF COENZYME B-12 BASE-OFF FORM ANALOGS- 2'-DEOXYNUCLEOSIDYLCOBINAMIDES

Three new analogs of coenzyme -12-2',5'-dideoxyadenosylcobinamide(2'dA doCbi(+)), 2',5'-dideoxycytidylcobinamide(2'dCytCbi(+)), and 5'-deoxyt hymidylcobinamide(ThyCbi(+))-were synthesized, at first, from tosylate d 2'-deoxynucleosides and B-12a to produce 2',5'-dideoxynucleosidylcob alamins, and then to remove the DMBz nucleotide loop at pH = 8-9 using Ce(OH)(3). They were characterized by UV-Vis and H-1 NMR spectroscopi es. A discussion on the spectral properties of them and a comparison w ith those of cobalamins containing 2'-deoxynucleosides were performed.