Quinazolinone–Hydrazine\nCyanoacetamide Hybrids\nas Potent Multitarget-Directed Druggable Therapeutics against Alzheimer’s\nDisease: Design, Synthesis, and Biochemical, In Silico, and Mechanistic\nAnalyses

The discovery of effective multitarget-directed ligands\n(MTDLs)\nagainst multifactorial Alzheimer’s disease (AD) remnants has\nbeen focused in an incessant drug discovery pursuit. In this perception,\nthe current study explores the rational design, synthesis, and evaluation\nof 26 quinazolinone–hydrazine cyanoacetamide hybrids <b>7(a–j)</b>, <b>8(a–j)</b>, and <b>9(a–f)</b> as MTDLs against AD. These new compounds were synthesized in four-step\nprocesses using simple phthalimide as the starting material without\nany major workup procedures and were characterized by different spectroscopic\ntechniques. In Ellman’s assay, the most potent analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were identified as\nselective and mixed-type inhibitors of hAChE. Furthermore, biophysical\nand computational assessments revealed that the analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were bound to both the catalytic\nactive site and peripheral anionic site of hAChE with high affinity.\nThe molecular dynamics simulation analysis highlighted the conformational\nchanges of hAChE upon binding of <b>7i</b>, <b>8j</b>,\nand <b>9d</b> and also the stability of resulting biomolecular\nsystems all over 100 ns simulations. In addition to antioxidant activity,\nthe most active congeners were found to protect substantially SK-N-SH\ncells from oxidative damage. Decisively, the most active analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were assessed as\npotent Aβ<sub>1–42</sub> fibril modulators and protective\nagents against Aβ<sub>1–42</sub>-induced toxicity in\nSH-SY5Y cells. Additionally, glioblastoma C6 cell-based assays also\ndemonstrated the use of the most active congeners <b>7i</b>, <b>8j</b>, and <b>9d</b> as protective agents against Aβ<sub>1–42</sub>-induced toxicity. Overall, this multifunctional\ncapacity of quinazolinone–hydrazine cyanoacetamide hybrids\ndemonstrated the noteworthy potential of these hybrids to develop\nas effectual MTDLs against AD. However, further pharmacokinetics,\ntoxicology, and behavioral studies are warranted.