Synthesis and antitumor activity of 2,5-bis(3'-indolyl)-furans and 3,5-bis(3'-indolyl)-isoxazoles, nortopsentin analogues.

A series of novel 2,5-bis(3'-indolyl)furans and 3,5-bis(3'-indolyl)isoxazoles were synthesized as antitumor agents. The antiproliferative activity was evaluated in vitro toward diverse human tumor cell lines. Initially 5 isoxazoles and 3 furan derivatives were tested against a panel of 10 human tumor cell lines and the most active derivatives 3c and 4a were selected to be evaluated in an extended panel of 29 cell lines. By exhibiting mean IC(50) values of 17.4 microg/mL (3a) and 20.5 microg/mL (4c), in particular 4c showed a high level of tumor selectivity toward the 29 cell lines.