Sesquiterpene lactones XVII. Cytostatic and pharmacological activity

Of four lactones studied in the systems Sa-180, EAC and L-1210, two compounds: alatolide, (ALA) and eupatoriopicrin (EUPP), according to the criteria of CCNSC, showed high cytostatic activity, and ursiniolide A (URSA) "moderate" cytostatic activity against at least one type of transplantable tumor. Two compounds were selected for further confirmatory investigation: EUPP, which gave 92% inhibition of EAC and 60% increase in survival of animals bearing Leukemia L-1210; and ALA, which gave 96% inhibition of growth of EAC.