1,N(6)-Etheno-cAMP 1,N(6)-Ethenoadenosine 3',5'-monophosphate 1,N(6)-Ethenoadenosine3',5'-cyclic monophosphate 3-(3,5-O-Phosphinico-beta-D-ribofuranosyl)-3H-imidazo(2,1-i) purine 38806-37-0 Etheno-cyclic amp