Novel Cannabidiol-Carbamate Hybrids As Potent BuChE Inhibitors: Docking-based Fragment Reassembly For The Development Of Potential Therapeutic Agents Against AD

Alzheimer’s disease（AD）is a degenerative disease of the nervous system.The number of patients is increasing,but there is still no effective way to treat AD.There are many hypotheses that point to the pathogenesis of AD,such as the genetic hypothesis and the Aβamyloid plaque hypothesis.Many drugs currently on the market are cholinesterase（Ch Es）inhibitors,such as rivastigmine and donepezil.The cholinergic hypothesis mainly states that the impairment of learning and memory in AD is mainly related to the loss of cholinergic neuron damage and the weakened transmission of cholinergic neurons in the hippocampus and other brain regions.Therefore,such drugs increase the level of acetylcholine（ACh）in the brain.It is the main reason for the improvement of AD symptoms.Ch Es mainly include acetylcholinesterase（ACh E）and butyrylcholinesterase（Bu Ch E）,which are important roles in regulating the level of ACh in the brain.When the brain is healthy,ACh E mainly degrades Ach,and ACh E activity accounts for 80%,while Bu Ch E plays a supporting role.When ACh is at a low concentration,ACh E occupies a dominant position,but when ACh is at a high concentration,Bu Ch E has a higher hydrolysis efficiency.As AD develops from early stage to middle stage or even late stage,Bu Ch E activity accounts for an increasing proportion,and ACh E activity remains unchanged or decreases.In addition,ACh E inhibitor has many side reactions,compared with Bu Ch E inhibitor,which is much better,so the development of butyrylcholinesterase inhibitors has great potential.Cannabidiol（CBD）is one of the main components of marijuana,it has no psychoactive,and studies have found that CBD also has the effect of inhibiting addiction,which indicates that cannabidiol may have antipsychotic effects.Research results have pointed out that CBD has a neuroprotective effect and it has been confirmed in AD transgenic animal models that CBD has the effect of improving AD symptoms.Carbamates are the most popular ACh E inhibitors.It has a deep impression on AD related research.Its representative drug rivastigmine is a dual inhibitor of ACh E and Bu Ch E and has a carbamate part.One of the most widely used anticholinesterase drugs.Rivastigmine has a pseudo-irreversible inhibitory effect on Ch Es,which can prolong its effective time in the body,and by slowing down the formation of amyloidβ?amyloid precursor protein fragments,reducing the formation of amyloid plaques,it can easily It penetrates the blood-brain barrier（BBB）and has a low degree of degradation in the CYP450 cytochrome system.CBD and rivastigmine have been launched as drugs for treating dementia and Ch Es are ideal drug targets.This study focused on developing novel Ch E inhibitors as drug leads against dementia through molecular modeling and fragment reassembly approaches.A potent carbamate fragment binding to active site gorge of Bu Ch E was identified via a docking-based structural splicing approach,thus,17 novel compounds were designed by structural reassembly.Compound C16 was identified as a highly selective potent Bu Ch E inhibitor(IC₅₀=5.3 n M,SI>4,000),superior to CBD(IC₅₀=0.67μM).C16 possessed BBB penetrating ability,benign safety,neuroprotection,antioxidant and pseudo-irreversible Bu Ch E inhibitor(K_d=13 n M,k₂=0.26 min^-1),showing good drug-like properties.In vivo studies confirmed that C16 almost entirely recovered the Aβ1?42（icv）-impaired cognitive function to the normal level,good anti-amyloidogenic effect.Hence,the potential Bu Ch E inhibitor C16 can be developed as a promising disease-modifying treatment of AD.