Inhibitors of adenosine 3',5'-cyclic monophosphate phosphodiesterase in Daphne genkwa Sieb. et Zucc.

Adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase inhibition testing provides a useful means for the screening of biologically active compounds contained in medicinal plants. We have identified cAMP phosphodiesterase inhibitors contained in various medicinal plants.2a-k) The present paper deals with the identification of cAMP phosphodiesterase inhibitors contained in the flowers and buds of Daphne genkwa SIEB. et Zucc (Japanese name "Genka," Thymelaeaceae), which have been used as purgative, diuretic and expectorant agents in traditional medicine. As constituents, flavones3) and a diterpene4) have beeen isolated. Apigenin and luteolin have been reported to be strong xanthine oxidase inhibitors.5)