Among the three types, enmein-, oridonin-, and trichorabdal-type, of diterpenoids from Rabdosia trichocarpa, the latter showed the highest antitumor activity against Ehrlich ascites carcinoma in mice. Their potent activities were attributed to synergistic increase arising from the presence of two
A significant antitumor activity of oridonin (1) and lasiokaurin (2), the kaurene-type diterpenoids of Isodon species, was shown by their i.p. injection to the test mice inoculated by Ehrlich ascites carcinoma. Enmein (8), compounds 9 and 3 were also active under larger dose. Subsequently, the