C₁₇H₁₈N₅O₆P; MW 419.3; λ_max 258 nm; ε 15000. Purity > 97% HPLC for mixture of axial and equatorial isomers. Hydrolysis slowly releases the polar cAMP which is trapped inside the cell and subsequently metabolized, resulting in an elevated cAMP level for a prolonged period. Detailed technical information and updated reference list available. Ref.: Engels et al., J. Med. Chem., 20, 907 - 911 (1977).