Synthesis and biological applications of some novel 8-Hydroxyquinoline urea and thiourea derivatives

A number of novel urea and thiourea derivatives of 8-hydroxyquinoline have been designed, synthesized and evaluated for their anticancer activities. The structures of the new compounds were established by spectroscopic techniques, ¹H NMR, ¹³C NMR, and mass spectrometry. The in vitro cytotoxicity against MCF7, and MDA-MB-231 cell lines were assessed by MTT assay. Six of the 11 compounds synthesized namely 5b, 5c, 5f, and 6b-d exhibited cytotoxicity with IC₅₀ values ranged between 0.5 and 42.4 µM. Apoptotic features of cells treated with 5b compound were observed via florescent microscopy using DAPI and ethidium bromide/acridine orange staining against MCF-7 cells. Molecular docking of these molecules against 16 potential breast cancer protein revealed that these compounds could interact with the active site of poly (ADP-ribose) polymerase-1 (PARP1), B-cell lymphoma-extra large (Bcl-xL) and PARP5A (Tankyrase 1) by forming hydrogen bonds, π-π interactions and hydrophobic interactions. The docked poses of these molecules were observed to be similar in the active site of each of these targets.