Jozsef Beres

Conformational studies of phosphorus-containing ring systems of pharmacological and biochemical importance-derivatives of cyclophosphamide and cyclic nucleotides

Abstract Results of a systematic study of the conformational features of the 1, 3, 2-oxazaphosphorinane ring system characteristic of the antitumor drug cyclophosphamide and its congeners are reported. Comparisons are made to the related 1, 3, 2-dioxaphosphorinane ring system of nucleoside cyclic 3′, 5′-monophosphates, e. g. cAMP and cTMP, and their neutral derivatives, I.

Conformational Properties of the Phosphate Rings of Neutral Phosphoramidate Derivatives of Ribo- and 2′-Deoxyribonucleoside Cyclic 3′,5′-Monophosphates

Abstract An investigation of the effects of changing the nature of X, nitrogen base (B), and amino substituent (R2N) on the equilibrium 1⇆2 was carried out. The influence of the above structural changes on the time-averaged coupling constants JAP and JBP, determined at 300 MHz, were used to follow changes in Keq. With constant R2N, small effects from variation of X and B were found. A large range in Keq arose from changes in the steric size of R2N. These results will be related to the question of the ease of chair to twist interconversion of the phosphate ring essential to the biological activities of the naturally occurring diesters, cAMP and cGMP.

Alkaline degradation of 1,3-Di-(2-Hydroxyethyl)adenosine 3′,5′-cyclic phosphate. Studies on the reaction products

Abstract 1,3-Di-(2-hydroxyethyl)adenosine 3′,5′-cyclic phosphate (1) in 1 M NaOH failed to undergo the expected Dirmroth rearrangement. Rather, pyrimidine ring opening followed by loss of ethylene oxide and formate yielded 5-amino-1-(β-D-ribofuranosyl)imidazole-4-(N-(2-hydroxyethyl)-carboxamidine) 3′,5′-cyclic phosphate (2) as the major product. The 3′-monophosphate (3) and 2′-O-hydroxyethyl (4) derivatives of 2 were also isolated and characterized.