A Promising Acetylcholinesterase and Butyrylcholinesterase Inhibitors: in Vitro Enzymatic and in Silico Molecular Docking Studies of Benzothiazole-Based Oxadiazole Containing Imidazopyridine Hybrid Derivatives

Alzheimer's dementia (AD), the most prevalent neurodegenerative disorder adversely affecting elderly citizens worldwide, is an incurable disorder with no effective medication found till date. Taking into account the seriousness of this issue, imidazopyridine-based benzothiazole-oxadiazole hybrid derivatives were synthesized as anti-Alzheimer's agents. The efficacy of these scaffolds was compared with the standard Donepezil (IC50 = 14.47 ± 1.20 μM for AChE and 19.90 ± 2.40 μM for BuChE). All the novel scaffolds exhibited biological activity covering a range of IC50 = 6.70 ± 1.65 μM and 41.65 ± 7.20 μM for AChE and 6.40 ± 1.80 μM for AChE and 44.65 ± 7.40 μM for BuChE. Analog 6p having IC50 = 6.70 ± 1.65 μM for AChE and 6.40 ± 1.80 μM for BuChE was found as the lead candidate of the series with maximum inhibition due to presence of small sized and highly electronegative fluoro moieties, inhibiting the enzymes through effective hydrogen bonds. These effective interactions were also studied in molecular docking investigations of the lead compounds. Furthermore, ADME analysis conducted in this study assisted the drug likeness of the potent analogs. Synthetic and structural confirmation of the hybrid derivatives was achieved through 13C NMR, 1H NMR and HREI-MS.