Rapid synthesis of 14C forskolin by a route suitable for 11C labeling

Radiolabeled forskolin was synthesized by acetylation of deacetylforskolin with 14C-labeled acetic acid in the presence of dicyclohexylcarbodiimide. Separation of labeled forskolin of greater than 97% radiochemical purity was achieved by HPLC with a reversed-phase column. The synthesis and purification of labeled forskolin were achieved in less than 30 min and the radiochemical yield of labeled forskolin after HPLC purification was about 30%, These methods are therefore applicable for production of 11C-forskolin which may be useful for PET second messenger imaging.