Synthesis and reactivity of guanosine 3′,5′-phosphoric acid alkyl esters

Guanosine 3′,5′-phosphoric acid alkyl esters were synthesized by reaction of the free acid of guanosine 3′,5′-phosphate (cGMP) with the appropriate diazoalkane. The resulting pair of diastereoisomers was separated chromatographically, and the conformations were assigned on the basis of ³¹P-nmr. Hydrolysis of the compounds in water was measured, and their half-lives were determined. The ability of the compounds to act as substrates for phosphodiesterase from beef heart was tested, and their inhibition of this enzyme was measured.