Design, Synthesis, and Anticancer Activities of Benzofuran–Isatin Hybrids Tethered by Pentylene and Hexylene

Fourteen benzofuran-isatin hybrids 6a-f and 7a-h tethered via alkyl linker (pentylene and hexylene) were designed and synthesized, and hybrids 6c-f and 7a-h were screened for their in vitro anticancer activity against various human cancer cell lines. The majority of the hybrids were active against the tested cancer cells, and the most active hybrids 7g (half maximal inhibitory concentration/IC50: 77.2-88.9 mu M) and 7h (IC50: 65.4-89.7 mu M), which possessed broad spectrum anticancer activity were as potent as the reference vorinostat (IC50: 64.2->100 mu M) against all tested cancer cell lines, could act as leads for further investigations. The structure-activity relationship is also discussed, and the enriched structure-activity relationship may afford useful information for further rational design of the candidates with higher activity.