Abstract
Condensation of the cis-diol of adenosine (1a) or guanosine (1b) with ethyl levulinate led to the acetal-esters 2a or 2b. Phosphorylation with phosphorous oxide trichloride converted them into their 5'-monophosphates. On alkaline hydrolysis the acetal-esters 2a,b as well as their 5'-monophosphates gave the carboxylic acid derivatives 3a,b and 4a,b, respectively. Condensation of these acid derivatives with aminohexyl-agarose (5) using water soluble N-ethyl-N'-(3'-dimethyl-aminopropyl)-carbodiimide hydrochloride as coupling reagent led to the new polymers 6a/6b and 7a/7b. This method of preparing resin linked adenosine and guanosine derivatives should be generally applicable to any ribonucleoside or ribonucleotide with a cis-diol. Because of the widespread occurence of these molecules, particularly as cofactors of enzymes, the new polymers might be useful tools for the purification of certain classes of enzymes by affinity chromatography.