| Summary: | 23-Hydroxybetulinic acid (<strong>1</strong>) served as the precursor for the synthesis of C-28 ester derivatives. The target compounds were evaluated <em>in vitro</em> for their antitumor activities against five cell lines (A549, BEL-7402, SF-763, B16 and HL-60)<em>.</em> Among the obtained compounds, <strong>6i</strong> had the most potent antitumor activity, with the IC<sub>50</sub> values of 8.35 µM in HL-60 cells and showed similar antitumor activity as cyclophosphamide in H22 liver tumor and as 5-fluorouracil in B16 melanoma<em> in vivo</em>.
|
|---|