Design, Synthesis And Anti-TSWV Mechanism Of Piperazine Derivatives Containing α-ketoamide Structur

Piperazine,a diazahexaary heterocycle,has a wide range of biological activities,including:antiviral,bactericidal,herbicide,anti-inflammatory,anti-malarial,insecticidal,and anti-cancer activities,etc.In this study,by incorporatingα-ketoamide moiety into the lead structure,35 piperazine target compounds containingα-ketoamide moieties are generated,which is based on the fact that piperazine derivatives are an important structural molecule with a variety of biological functions.The Nicotiana glutinosa was used as the wilted host for the tomato spotted wilt virus（TSWV）in the systematic testing of the target compounds’anti-TSWV activity.A 3D-QSAR model was established with the EC₅₀ value of the inactivation activity of the compound against TSWV.In addition,the interaction mechanism between compounds 34 and 35 and TSWV virus was preliminarily explored by Agrobacterium-mediated method,molecular docking and Microscale thermophoresis（MST）.The main work was as follows:1.Designing and synthesizing 35 piperazine derivatives withα-ketoamide moieties;HRMS,¹H NMR,and ¹³C NMR were used to determine their structures.The anti-TSWV activity of the target compound 1-35 was tested.The results showed that most of the target compounds had good inhibition rate to TSWV.Compounds 34 and35 showed excellent anti-TSWV activity with EC₅₀ values of 62.4 and 59.9μg/m L,which were better than the control agents ningnanmycin（113.7μg/m L）and ribavirin（591.1μg/m L）.2.Compounds 34 and 35 were preliminarily investigated by Agrobacterium-mediated method and Western Blotting method to affect the formation of TSWV-infected RNP complex in Nicotiana benthamiana,and the inhibition rate was about70%.3.Molecular docking technology and Microscale thermophoresis（MST）technology were used to indicate that compounds 34 and 35 could inhibit the infection of the virus by binding to the nucleocapsid protein of TSWV to prevent the assembly of RNP of the core structure of the virus,and also showed that the 94-position arginine of TSWV N was a key site for the interaction between compounds and TSWV N target.Therefore,this study revealed the preliminary mechanism of action of novel piperazine derivatives containingα-ketoamide moieties against TSWV;This kind of compound can provide a new idea for the development of potential antiviral agents.