Antitumor activity of N-heterocyclic carboxaldehyde thiosemicarbazone derivatives

Antitumor activity of N-heterocyclic carboxaldehyde thiosemicarbazone derivatives was examined in ascites sarcoma-180 system. Among isoquinoline-1-carboxaldehyde thiosemicarbazone derivatives, the parent compound, IQ-1, was the most active and less toxic. On the other hand, among the pyridine-2-carboxaldehyde thiosemicarbazone derivatives tested, 5-acetoxymethyl and 5-isonicotinoyl derivatives were active, and their therapeutic indices were 190 and 54, respectively. In other tumor systems, acetoxymethyl derivative was markedly active against Ehrlich ascites carcinoma, leukemia L-1210, and leukemia C-1498, while moderately effective against Nakahara-Fukuoka sarcoma, but it was not active against adenocarcinoma-755. Isonicotinoyl derivative was markedly active against Ehrlich ascites carcinoma, leukemia L-1210, and leukemia C-1498, while moderately active against adenocarcinoma-755, and slightly active against Nakahara-Fukuoka sarcoma.