7-Isopentenyloxycoumarin (1) was isolated from Heracleum lanatum Michx. (Umbelliferae). Compound 1 inhibited phospholipid metabolism and Epstein–Barr virus activation caused by a potent tumor promoter. In an in vivo experiment, topical application of 1 suppressed skin-tumor-formation induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in 7,12-dimethylbenz[a]anthracene (DMBA) initiated mice. And it also suppressed ornithine decarboxylase activity stimulated by TPA on mouse skin. These results indicated that 7-isopentenyloxycoumarin is one of the effective compounds from natural resources for treating skin tumor formation.
2002 The Pharmaceutical Society of Japan