PHOTOCHEMICAL PROPERTIES OF NEW PHOTOLABILE CAMP DERIVATIVES IN A PHYSIOLOGICAL SALINE SOLUTION

Three new photolabile esters of cAMP (2-anthraquinonyl)methyl (la), (7 -methoxycoumarinyl)methyl (2a), and 2-naphthylmethyl (3a), have been d eveloped. The stability and photochemical properties of these derivati ves were compared to the previously reported ones in a physiological s aline solution (1% DMSO in Ringer's solution, pH 7.4). We found that 2 a had satisfactory stability (t(1/2) > 1000 h) in the dark and was pho tolyzed to release the parent cAMP on 340 nm irradiation (phi(app) = 0 .10, epsilon(340) = 6730) more efficiently than previously reported ca ged cAMPs. A biological test using the melanophores of the medaka (Ory zias latipes) revealed that 2a penetrated into the melanophores, inact ive before irradiation and activated to release cAMP upon irradiation. We have developed a new caged cAMP which can be used in the investiga tion of biological responses regulated by intracellular cAMP concentra tions using living cells.