Cytotoxic ent-kaurane diterpenoids from Isodon sinuolata

Five (1-5) ent-kaurane diterpenoids and 17 other known ones, were isolated from Isodon sinuolata. Their structures were determined on the basis of spectroscopic methods. All compounds were evaluated for cytotoxicity against a small panel of cell lines. Some compounds exhibited significant cytotoxicity.