Antitumor principles ofStellera chamaejasme L.

Methanol extract of Stellera chamaejasme L was assessed for antitumor activity by an antitumor active bioassay against murine leukemia P388 in vivo . The bioassay-directcd separation of the extract furnished seven diterpene compounds (stellerarin, stelleramacrin, gnidimacrin, pimelea factor P 2 , subtoxin, huratoxin, simplexin ) and two biflavanone compounds (neochemae-jasmin A and B). Among them, gnidimacrin, stellerarin and stelleramacrin (a novel compound) were found to have high antitumor and cytotoxic activities against P388, L1210 and K562 in vivo and in vitro . The results suggested that the diterpene compounds were the potent antitumor principles of Stellera chamaejasme L.