Rapid Discovery Of Acetylcholinesterase Inhibitors By Sulfur Fluoride Exchange Reaction (SuFEx)

Alzheimer’s disease（AD）is the most common form of Alzheimer’s disease,commonly known as Alzheimer’s disease,also known as brain degeneration or Alzheimer’s disease.It is a progressive neurological degenerative disease that occurs in the elderly or pre elderly.Alzheimer’s disease not only has a serious impact on the quality of life and health of elderly people,but also brings enormous pressure to patients’families and society.For decades,relevant researchers have conducted in-depth exploration on the pathology and pathogenesis of Alzheimer’s disease in various aspects,and have made significant breakthroughs.The pathogenesis of Alzheimer’s disease is complex.Experts and scholars at home and abroad have carried out relevant research and discussion in molecular genetics,neurotransmitters,biochemistry and molecular biology,immune response and other aspects,and put forward different pathogenesis hypotheses,of which the more important is the cholinergic theory.Cholinesterase mainly includes two types,acetylcholinesterase and Butyrylcholinesterase.At present,donepezil,galantamine and kabalatin,which are listed drugs for the treatment of AD,are acetylcholinesterase inhibitors and are used to treat AD patients at different stages.By inhibiting acetylcholinesterase and the hydrolysis process of acetylcholine,acetylcholinesterase inhibitors increase the amount of acetylcholine in the brain of patients,thereby improving the memory function of patients and improving the cognitive ability of patients,so as to achieve the therapeutic purpose.The sulfur-containing group is the most widely distributed functional group in pharmacophore,and sulfonamides are commonly found in sulfur-containing drugs and agricultural chemicals.Sulfonyl fluoride is considered a more attractive alternative than sulfonyl chloride due to its superior stability and adjustable reactivity.The hub sulfonyl fluoride（R-SO₂F）and aryl fluoride sulfate（RO-SO₂F）in sulfur fluorine exchange reactions have been successfully used for lead discovery and many active molecules in chemical biology.Sulfur fluoride exchange（Su FEx）click chemistry can be used in the efficient assembly process between sulfonyl fluoride core groups and amine groups to form a library of sulfonamide cholinesterase targeted inhibitors,and then directly conduct biological screening to identify potential"lead compound".Here,this study shows a process based on biocompatibility Su FEx click chemistry chemistry（H2L,hit to lead）.According to fragment based drug discovery strategy（FBDD）,containing sulfonylfluoride[R-SO₂F]motif(ACh E inhibition,IC₅₀=3-9μM).In Su FEx reaction,the hits of the fragments were rapidly diversified into 105 analogues,and the sulfa products were directly screened to produce drug inhibitors with 70 times higher potency(IC₅₀=94 n M),and it was found that the inhibition of acetylcholinesterase was more obvious.Finally,compound J8-A34 was selected for subsequent drug resistance experiments.The experimental results of ee ACh E inhibition kinetics showed that this compound can serve as a reversible competitive inhibitor（K_i=128n M）.The docking experiment of compound J8-A34 with h ACh E molecule found that it had a relatively stable binding mode.The ethylene linked benzyl piperidine fragment not only went deep into the bottom of the active site,but also observed the hydrogen bond interaction,π-πinteraction andπ-cation interaction with Trp86,Glu202,Tyr337 and Phe338.The relatively stable binding mode enabled the compound to play an inhibitory role fully and within a certain period of time.At the same time,this compound has good permeability and safety,demonstrating good neuroprotective effects in the PC12 cell injury model induced by H₂O₂.In addition,compound J8-A34 showed improvement in cognitive function in a mouse model induced by Aβ_1-42.Due to the successful use of this Su FEx linkage reaction at the picomol level for direct screening,this method can accelerate the development of robust biological probes and candidate drugs.