This thesis addresses a novel approach to the treatment of Alzheimer's disease (AD) by the design and synthesis of novel dual inhibitors, targeting two key enzymes butyrylcholinesterase (BChE) and mitogen-activated kinase p38α.
Alzheimer's disease is a neurodegenerative disorder characterised by cognitive decline and is closely associated with dysregulation of cholinergic neurotransmission and neuroinflammatory processes mediated by p38α MAPK. Inhibition of BChE improves cognitive function by increasing the concentration of the neurotransmitter acetylcholine, inhibition of p38α MAPK kinase reduces neuroinflammation and hyperphosphorylation of tau protein, which could improve the clinical signs manifested in AD.
Based on a selective p38 MAPK inhibitor, compound ARRY-371797, we designed six new compounds, labelled as 9, 10, 16, 22, 28. Based on a literature search, we developed a six-step synthesis starting from methyl 2-fluoro-4-methyl-5-nitrobenzoate. Our final compounds differ from compound ARRY-371797 in 4 substituents replacing the 2,4-difluorophenyl group. With the new substituents we wanted to maintain or increase the inhibition potency of p38α MAPK and BChE. The compounds were purified and their structure confirmed by spectroscopic methods and their residual activity determined by biochemical assays on recombinant enzymes. Among all inhibitors, compound 9 was found to be the most promising with an IC50 value of 6.4 µM against human (h)BChE and with and IC50 = 0.28 µM against p38α MAPK.
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