Synthesis and antitumor activity of fused quinoline derivatives. II. Novel 4- and 7-hydroxyindolo-[3,2-b]quinolines.

Novel indolo[3,2-b]quinoline derivatives (1c--f), which carried a methoxy or a hydroxy group at the 4- or 7-position of the lead compound 1a, were prepared and their antitumor activities against P388 in mice were examined. Except for the 4-hydroxy derivative (1d), these showed remarkably potent activity. Among these compounds, the 7-hydroxy derivative (1f) was the most potent one (optimal dose = 50 mg/kg, the median survival time of treated group/control group (T/C) greater than 330%, cure = 5/6).