Dual inhibitors of Interleukin-6 and acetylcholinesterase for treatment of Alzheimer's disease: Design,docking, synthesis and biological evaluation

Multitarget compounds intercept two or more functionally complementary pathways simultaneously, and are therefore considered to have potential in effectively treating complex multifactorial diseases like Alzheimer's disease (AD). In the present study, novel molecules are designed by coupling a chromone and a N,N-disubstituted carbamoyl amine as pharmacophore for interleukin-6 (IL-6) and acetylcholinesterase (AChE) inhibition, respectively. Four series (Y1–Y4) of 40 compounds are designed by using alkyl linkers of different lengths (1–4 carbon atoms) for the coupling of the two selected pharmacophore. Docking of all designed compounds in AChE leads to the identification of twelve best fit compounds (Docking score >8.3). The data suggests that a 1- or 2-carbon atom linker is the most conducive to orient the pharmacophore for optimum binding with AChE active site. The predicted ADME properties of the 12 selected compounds suggest that these can cross the blood brain barrier (BBB) with good oral bioavailability. These compounds are synthesised and evaluated for anti-AChE activity. Five compounds, showing >45% inhibition of AChE, are further evaluated for IL-6 inhibitory activity. Compound Y1f is found to be the most potent inhibitor of both AChE and IL-6 (IC₅₀ 0.7 and 0.8 ​μM, respectively). It suggests that a chromone moiety connected to a piperidine ring through a 1-carbon atom linker may provide a useful template to medical chemists for the development of new chemical entities effective against AD.