2'- O- (2- Aminoethylcarbamoyl)adenosine- 3', 5'- cyclic monophosphorothioate, Rp- isomer; immobilized on agarose gel (Rp-2'-AEC-cAMPS-Agarose)[2'- O- (2- Aminoethylcarbamoyl)adenosine- 3', 5'- cyclic monophosphorothioate, Rp- isomer; immobilized on agarose gel (Rp-2'-AEC-cAMPS-Agarose)]