CYTOTOXIC TRITERPENOIDS FROM THE LEAVES OF EUPHORBIA-PULCHERRIMA

Two cytotoxic triterpenes have been isolated from Euphorbia pulcherrim a. Their structures and stereochemistry have been established from NMR , IR, and El-mass spectroscopy. The compounds were identified as 9,19- cycloart-23-ene-3 beta,25-diol and 9,19-cycloart-25-ene-3 beta,24-diol . Cytotoxicity evaluation was performed using Ehrlich ascites tumor ce lls. While cycloartenol induced no cytotoxic activity against Ehrlich ascites tumor cells, both isolated triterpenes exhibited cell inactiva ting effects. The IC50 is approximately 7.5 mu M, while the IC90 is ap proximately 13.5 mu M for 9,19-cycloart-25-ene-3 beta,24-diol. The 3 b eta,25-diol compound is 50% less active.