Beschreibung:
<jats:title>10-15</jats:title>
<jats:p>Fourteen ursolic acid derivatives, among them four novel compounds, were synthesized by modification either at the C-3, C-28 or both positions. The cytotoxic activity of the obtained derivatives was evaluated against the four human cancer cell lines KB (human mouth epidermal carcinoma), HepG2 (human hepatocellular carcinoma), MCF7 (human breast carcinoma) and Lu (human lung carcinoma). As the result, compounds 7and 8were from two to three times more active than ursolic acid on all four tested cell lines. This is the first report on cytotoxic effects of the synthetized ursolic acid derivatives 4, 8, and .</jats:p>