Synthesis, Labeling and Biological Evolution of New Thiopyrano[2,3-b]pyridine Derivatives as Potential Anticancer Agents

The new thiopyrano[2,3- b ]pyridines 4 – 9 could be synthesized from the nicotinonitrile derivative 1 . The cytotoxicity activity of the selected compounds 5 , 6 and 8 was tested against MCF-7 and HCT -116 cell lines. The compound 5 ( TP 5 ) exhibited significant inhibitory activity and displayed the most potent activity, more than 6 and 8 . The compound 5 with potent inhibitory activity in tumor growth inhibition would be a potential anticancer agent. In the light of this result, the labeled 125 I-compound 5 ( 125 I -TP 5 ) was prepared and its cytotoxicity against ascites tumor in mice has been evaluated. The results show that compound 5 ( TP 5 ) may be potentially used as a radiopharmaceutical for tumor diagnosis when labeled with 125 I.