Quinazolinone–Hydrazine Cyanoacetamide Hybrids as Potent Multitarget-Directed Druggable Therapeutics against Alzheimer’s Disease: Design, Synthesis, and Biochemical, In Silico, and Mechanistic Analyses

The discovery of effective multitarget-directed ligands (MTDLs) against multifactorial Alzheimer's disease (AD) remnants has been focused in an incessant drug discovery pursuit. In this perception, the current study explores the rational design, synthesis, and evaluation of 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 processes using simple phthalimide as the starting material without any major workup procedures and were characterized by different spectroscopic techniques. In Ellman's assay, the most potent analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were identified as selective and mixed-type inhibitors of hAChE. Furthermore, biophysical and computational assessments revealed that the analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were bound to both the catalytic active site and peripheral anionic site of hAChE with high affinity. The molecular dynamics simulation analysis highlighted the conformational changes of hAChE upon binding of <b>7i</b>, <b>8j</b>, and <b>9d</b> and also the stability of resulting biomolecular systems all over 100 ns simulations. In addition to antioxidant activity, the most active congeners were found to protect substantially SK-N-SH cells from oxidative damage. Decisively, the most active analogues <b>7i</b>, <b>8j</b>, and <b>9d</b> were assessed as potent Aβ_1-42 fibril modulators and protective agents against Aβ_1-42-induced toxicity in SH-SY5Y cells. Additionally, glioblastoma C6 cell-based assays also demonstrated the use of the most active congeners <b>7i</b>, <b>8j</b>, and <b>9d</b> as protective agents against Aβ_1-42-induced toxicity. Overall, this multifunctional capacity of quinazolinone-hydrazine cyanoacetamide hybrids demonstrated the noteworthy potential of these hybrids to develop as effectual MTDLs against AD. However, further pharmacokinetics, toxicology, and behavioral studies are warranted.