Design,synthesis Of Novel Rutaecarpine Derivatives And Biological Evaluation On Multi-target-directed Anti-Alzheimer's Disease

Objective:Alzheimer's disease?AD?is the most common disease in Senile Dementia.Its main clinical manifestations are progressive memory loss and severe cognitive dysfunction.At present,the exact pathogenesis of AD is unknown.Current research indicates that the pathogenesis of AD involves different factors.The main pathological features of the disease include cholinergic neurotransmitter dysfunction and abnormal aggregation of?-amyloid protein?A??in the hippocampus and cortex of the brain,accumulation of tau protein,oxidative stress,imbalance of biological metal ions and neuroinflammation.Therefore,the development of multi-target anti-AD drugs against multiple factors has received widespread attention.Rutaecarpine?Ru?is one of the main constituents of the Chinese traditional medicine rutaceous evodia,which has many pharmacological effects.Based on the structural characteristics of rutaecarpine,the sulfonamide group with anti-Bu Ch E activity was linked at its 3 position to obtain a series of sulfonamide-substituted Ru derivatives.The synthetic derivatives were evaluated for multi-target anti-AD activity.Methods:Based on the Bergman method for synthesizing the structure of rutaecarpine,it was modified and introduced with side chain groups.In a concentrated sulfuric acid solution,potassium nitrate was added to dissolve,and the solution was stirred in an ice bath.A nitro group was introduced into the isatoic anhydride.In an anhydrous pyridine solution,condensation was performed by the trifluoroacetic anhydride method,and cyclization was performed under acidic conditions.Nitrogen was reduced using 80%hydrazine hydrate and 10%palladium carbon.Removal of trifluoromethyl in potassium hydroxide ethanol solution gave the key intermediate,3-amino rutaecarpine.Finally,the 3-position amino hydrogen atom of rutaecarpine were substituted by a series of benzenesulfonyl chloride and thiazolesulfonyl chloride fragments under anhydrous pyridine to form sulfonamide groups.The reaction produced a series of benzenesulfonylamino-substituted or thiazolesulfonamide-substituted Ru derivatives.Ellman assay was used to evaluate the in vitro ACh E and Bu Ch E inhibitory activity of two series of compounds,thereby obtaining compounds with better inhibitory activity.Enzyme kinetic experiments and molecular docking simulations were used to explore the binding modes of compounds and enzymes.Molecular dynamics simulation was used to study the structural stability of complexes formed by compounds and enzymes.Further,the biological activity of the compound as an anti-AD drug was studied through multi-target tests,including inhibition of A?aggregation,anti-inflammatory,antioxidant,chelation with biological metal ions,and neuroprotective ability.Results:In this study,a series of rutaecarpine derivatives were successfully designed and synthesized by introducing a sulfonamide aromatic side chain at the 3-position amino of rutaecarpine,and the biological activity was evaluated as a multi-target anti-AD drug.The results showed that most of the synthesized compounds had good inhibitory activity on Bu Ch E,and compound 6n showed the strongest inhibitory activity on Bu Ch E(IC₅₀=3.60±0.34?M).Lineweaver-Burk diagrams and molecular docking showed that compound 6n inhibited Bu Ch E activity through combinations of peripheral anion sites?PAS?and catalytic sites?CAS?.The molecular dynamics simulation results showed that the 6n has a strong affinity with Bu Ch E.In addition,compound 6n could effectively reduce intracellular ROS accumulation induced by H₂O₂.The results indicated that compound 6n could be used as a novel antioxidant.In addition,compound 6n exhibited good drug-like properties and could selectively chelate with Cu²⁺.And compound 6n could inhibit the aggregation of A?,thereby effectively preventing the rapid generation of spots.Compound 6n also showed neuroprotective effects on PC12 and SH-SY5Y cytotoxicity induced by H₂O₂or A?.Conclusion:The above experimental results showed that compound 6n had great development potential as MTDL for treating AD.This study also provided a basis for the development of anti-AD drugs with 3-sulfonamide-substituted Ru as the core structure.