New abietane norditerpenoid from Salvia miltiorrhiza with cytotoxic activities.

One new abietane-type norditerpenoid, named militibetin A (1), was isolated from the dry roots of Salvia miltiorrhiza, along with two known diterpenoids, yunnannin A (2) and ferruginol (3). Their structures were established by means of extensive spectroscopic analyses. In vitro, compounds 1-3 were found to show cytotoxicities against selected cancer cells, including P-388, HONE-1, and HT-29, and gave ED(50) values in the range of 2.9-5.4 μg ml(- 1).