Design,Synthesis And Anti-NASH Activity Evaluation Of Novel Magnolol And Honokiol Derivatives

Nonalcoholic steatohepatitis（NASH）is an important and irreversible link in the development of nonalcoholic fatty liver disease（NAFLD）into liver fibrosis and even liver cancer.Its incidence rate is increasing year by year and shows a trend of younger age,which seriously threatens human health.There are no clinical specific drugs approved for the treatment of NASH on the market.The new drugs under development currently in the clinical research period are mainly aimed at different pathogenesis,including PPAR receptor agonists,antioxidants,insulin sensitizers,anti-inflammatory drugs,etc.In this regard,it has become an urgent task to find suitable therapeutic targets and successfully develop new specific therapeutic drugs against NASH.Magnolol and honokiol are natural active monomers containing allyl bisphenol isolated from magnolia officinalis.A large number of studies have confirmed that they can not only improve lipid peroxidation and insulin resistance of liver cells,but also inhibit the expression of inflammatory related factors in the liver,which has a positive effect on the treatment of NASH,and is a leading compound with good development potential.Ebselen is the most widely studied multifunctional organic selenium compound.It can simulate the function of glutathione peroxidase,enhance insulin receptor sensitivity,and protect liver tissue from the effects of lipid peroxidation and inflammation.Indole-3-propionic acid is a tryptophan metabolite produced by intestinal bacteria.It can not only inhibit liver lipid synthesis and proinflammatory cytokine expression,but also improve intestinal ecological imbalance,reduce endotoxin leakage,and prevent the occurrence and development of NAFLD.In order to find new anti-NASH magnolia derivatives with better anti-inflammatory and antioxidant activities,based on the structure-activity relationship between magnolol and honokiol,two series of magnolia derivatives were designed by using benzoisoselenidone and indole-3-propionic acid as basic skeletons,through amide bond and ester bond respectively with magnolol and honokiol.Through computer-aided drug design technology,the drug-like properties of the designed derivatives are predicted,and the derivatives with good drug-like properties are combined with PPARγCombined with crystal structure（PDB:3R5N）for docking analysis,select derivatives with higher affinity and better binding mode for synthesis and subsequent anti-NASH activity research.17 amide bond derivatives and 11 ester bond derivatives with good drug properties and high affinity with protein were synthesized by amidation,Ullmann reaction and hydrolysis reaction.All the intermediates and end products were characterized by ¹H NMR,¹³C NMR,HPLC,m.p.and MS.The toxicity of the synthesized derivatives was evaluated by MTT method and the activity test was carried out with the maximum concentration measured by MTT method to evaluate the effects of the synthesized derivatives on the contents of TG,ROS or NO in the cells of NCTC-1469 and RAW264.7.The results showed that:（1）10μmol/m L Eb-MK-5 and Eb-HK-10 and 40μmol/m L Eb-HK-2 and Eb-HK-23 significantly inhibited the content of TG in NCTC-1469 cells,indicating that they had certain lipid-lowering activity.（2）Eb-MK-5,Eb-HK-2 and Eb-HK-5 all decreased the ROS content of NCTC-1469 cells at the dose of 10μmol/m L,but there was no significant difference.（3）We screened and obtained 20 magnolia officinae derivatives with potential to resist NASH,among which Eb-HK-2,Eb-HK-10 and Eb-HK-23 derivatives showed excellent lipid-lowering and anti-inflammatory activities,which should be further studied.（4）Different administration concentrations（10μmol/m L,20μmol/m L,40μmol/m L）of IPA-MK-2 could reduce the content of NO in RAW264.7 cells,but there was no significant difference.Based on the above activity experiment results,we screened 20 magnolia officinalis derivatives that may have anti-NASH potential,and preliminatively discussed the structure-activity relationship of their lipid-lowering and anti-inflammatory activities.Eb-HK-2,Eb-HK-10 and Eb-HK-23derivatives all have better lipid-lowering and anti-inflammatory activities,which can be further studied.The purpose of this paper is to screen the seedy compounds with significant anti-inflammatory and antioxidant effects,and provide new ideas for targeted treatment of NASH.