New Amino Acid Schiff Bases as Anticancer Agents via Potential Mitochondrial Complex I-Associated Hexokinase Inhibition and Targeting AMP-Protein Kinases/mTOR Signaling Pathway.

Two series of novel amino acid Schiff base ligands containing heterocyclic moieties, such as quinazolinone - and indole - were successfully synthesized and confirmed by spectroscopic techniques and elemental analysis. Furthermore, all compounds were investigated in silico for their ability to inhibit mitochondrial NADH: ubiquinone oxidoreductase (complex I) by targeting the AMPK/mTOR signaling pathway and inhibiting hexokinase, a key glycolytic enzyme to prevent the Warburg effect in cancer cells. This inhibitory pathway may be an effective strategy to cause cancer cell death due to an insufficient amount of ATP. Our results revealed that, out of 18 compounds, two ( and ) were top-ranked as they exhibited the highest binding energies of -8.8, -13.0, -7.9, and -10.0 kcal/mol in the docking analysis, so they were then selected for in vitro assessment. Compound promoted the best cytotoxic effect on MCF-7 with IC = 64.05 ± 0.14 μg/mL (0.135 mM) while compound exhibited the best cytotoxic effect on MDA-231 with IC = 46.29 ± 0.09 μg/mL (0.166 mM) Compounds and showed significant activation of AMPK protein and oxidative stress, which led to elevated expression of p53 and Bax, reduced Bcl-2 expression, and caused cell cycle arrest at the sub-G/G phase. Moreover, compounds and showed significant inhibition of the mTOR protein, which led to the activation of aerobic glycolysis for survival. This alternative pathway was also blocked as compounds and showed significant inhibitory effects on the hexokinase enzyme. These findings demonstrate that compounds and obeyed Lipinski's rule of five and could be used as privileged scaffolds for cancer therapy via their potential inhibition of mitochondrial complex I-associated hexokinase.