Design,Synthesis Of Hesperetin Derivatives, And Their The Pharmacological Activity Related To Anti-Alzheimer Disease

With the aging of our population,senile diseases have become an important disease that threat human health.Alzheimer's Disease?AD?is a chronic,progressive disease characterized by memory loss and cognitive impairment.And as the incidence of AD increases year by year,it has become the third largest disease that threat the health of the elderly.Cholinergic theory that in a large number of AD patients with brain degeneration and loss of neurons is the leading cause of memory and cognitive decline in patients with the main reason.Currently,based on acetylcholinesterase?AChE?design,synthetic anti-AD drugs are the most clinically used drugs.However,the effect of AChE inhibitors on AD treatment were only effective for patients with mild to moderate AD and were ineffective for patients with advanced AD,and AChE inhibitors cannot reverse AD disease or delay the development of the disease.Therefore,it is significant to find new and effective drugs for the clinical treatment of AD.Looking for active ingredients from natural products,and structural modification of the active structure is an important way to find new drugs.Based on the structural characteristics of the AChE double-site inhibitor,we designed and synthesized a series of new hesperetin derivatives as anti-Alzheimer's disease?AD?.At the same time,this new class of synthetic hesperetin derivatives for preliminary screening of pharmacological activity.Methods:According to the three-dimensional structural characteristics of acetylcholinesterase,we designed a series of terminal aryl side-chain substituted hesperetin derivatives at the 7-position of hesperetin.Combining the two sites of AChE,the structure of the compound was confirmed by mass spectrometry,hydrogen spectroscopy,melting point,and so on.AChE inhibition assay and butyrylcholinesterase inhibition assay,screening for highly selective and highly active compounds of AChE for further experimental studies;molecular docking experiments simulating the binding of compounds to AChE to verify the rationality of derivative design.A pharmacokinetics test of AChE inhibitory activity to verify whether compounds inhibit AChE activity by competitive binding,non-competitive binding or mixed binding;antioxidants were also tested on all compounds to evaluate whether the derivatives passed antioxidant effects.Reducing the inflammatory response to AD disease;at the same time,due to the correlation between cholinesterase activity and?-amyloid production,A??1-42?aggregation inhibition test was conducted in this study to measure the inhibitory effect of the compound on A?aggregation.At the same time,compounds were also used to inhibit H2O2-induced neuronal apoptosis and cytotoxicity experiments.Results:The AChE and butyrylcholinesterase inhibition tests showed that the compounds exhibited nice inhibitory activity against AChE and poor inhibitory activity against butyrylcholinesterase with a selectivity coefficient of 68 to 305,and the inhibitory activity of the 4f of AChE was the highest(IC₅₀=9.37±0.87nM),and its selectivity to AChE and butyrylcholinesterase was 305.The results of Lineweaver-Burk plot showed that all the 4 concentrations of 4f at 0,2.0,4.0 and 8.0nM linear extension lines intersect at the second quadrant,and the molecular simulation results show that compound 4f can bind to both PAS and CAS of AChE site.Antioxidant results showed that the ORAC values for the 4f,4g and 4o compounds were 3.0,3.1 and 3.1,respectively.Compound A??1-42?aggregation inhibition test results showed that all compounds showed the best inhibitory activity at20?M with IC₅₀ value of 8.47±0.44?M,which was significantly superior to that of curcumin at 16.25±0.15?M.H2O2-induced neuronal apoptosis experiments,the compound 4f has a neuroprotective effect.Cytotoxicity assays have shown that the compounds are less cytotoxic and almost nontoxic to cells at effective therapeutic drug concentrations.Conclusion:Based on the above experimental results,hesperetin derivatives can bind to AChE at two sites to inhibit the activity of AChE and it is also have inhibit the aggregation of A??1-42?,anti-oxidant and the protective effect of nerve cells.However,the animal experiments,clinical treatment experiments and structural remodeling at other positions of these hesperetin derivatives still need further study.