Synthesis and cytotoxic activity evaluation of indolo-, pyrrolo-, and benzofuro-quinolin-2(1H)-ones and 6-anilinoindoloquinoline derivatives Original Research Article

Certain indolo-, pyrrolo-, and benzofuro-quinolin-2(1H)-ones 4a,b, 6, 8, 16a–c and 6-anilinoindoloquinoline derivatives 10a,b, 11a,b, 12a,b have been synthesized and evaluated in vitro against a 3-cell lines panel consisting of MCF7 (Breast), NCI-H460 (Lung), and SF-268 (CNS). Those active compounds 4a,b, 6, 8, 10a,b, 11a,b, 12a,b were then evaluated in the full panel of 60 human tumor cell lines derived from nine cancer cell types. The results have shown that cytotoxicity decreases in the order of 6-anilinoindoloquinolines>indoloquinolin-2(1H)-ones>pyrroloquinolin-2(1H)-ones>benzofuroquinolin-2(1H)-ones. Among them, 1-[3-(11H-indolo[3,2-c]quinolin-6ylamino)phenyl]ethanone oxime hydrochloride (11a) and its 2-chloro derivative (11b) were most active, with mean GI50 values of 1.70 and 1.35 μM, respectively. Both compounds 11a,b were also found to inhibit the growth of SNB-75 (CNS cancer cell) with a GI50 value of less than 0.01 μM, and, therefore, were selected for further evaluation for in vivo antitumor activity.