Author's Organization：School of Pharmaceutical Sciences, Toho University School of Pharmaceutical Sciences, Toho University Faculty of Pharmaceutical Sciences, University of Tokyo Department of Pharmacy, College of Science and Technology, Nihon University Department of Pharmacy, College of Science and Technology, Nihon University
Aurantio-obtusin and obtusin were identified as inhibitors of adenosine 3', 5'-cyclic monophosphate (cAMP) phosphodiesterase in seeds of Cassia obtusifolia L. and Cassia tora L. The structure-activity relationships of 22 anthraquinones and 17 analogous compounds were studied. Anthraquinones of the emodin and obtusin types were generally more inhibitory towards cAMP phosphodiesterase than other types of anthraquinones, anthrones and lactones.
