Synthesis, Structure, Chemical Stability, and In Vitro Cytotoxic Properties of Novel Quinoline-3-Carbaldehyde Hydrazones Bearing a 1,2,4-Triazole or Benzotriazole Moiety.

A small library of novel quinoline-3-carbaldehyde hydrazones (Series 1), acylhydrazones (Series 2), and arylsulfonylhydrazones (Series 3) bearing either a 1,2,4-triazole or benzotriazole ring at position 2 was prepared, characterized by elemental analyses and IR, NMR, and MS spectra, and then subjected to in vitro cytotoxicity studies on three human tumor cell lines: DAN-G, LCLC-103H, and SISO. In general, compounds , , and substituted with a 1,2,4-triazole ring proved to be inactive, whereas the benzotriazole-containing quinolines , , and elicited pronounced cancer cell growth inhibitory effects with IC values in the range of 1.23⁻7.39 µM. The most potent 2-(1-benzotriazol-1-yl)-3-[2-(pyridin-2-yl)hydrazonomethyl]quinoline () showed a cytostatic effect on the cancer cell lines, whereas ′-[(2-(1-benzotriazol-1-yl)quinolin-3-yl)methylene]-benzohydrazide () and ′-[(2-1-benzotriazol-1-yl)quinolin-3-yl)methylene]-naphthalene-2-sulfonohydrazide () exhibited selective activity against the pancreas cancer DAN-G and cervical cancer SISO cell lines. Based on the determined IC values, the compound seems to be leading compound for further development as anticancer agent.