Study On Anthrax Ethal Factor Inhibitor

Anthrax is a malignant infectious disease caused by Bacillus anthracis and is one of the three most dangerous chemical and biological weapons in the world(the other two are variola virus and sarin).Anthrax is the main cause of anthrax infection,which is caused by the release of anthrax toxin.The anthrax toxin includes three virulence factors: protective antigen(PA),lethal factor(Lethal factor,LF)and edema factor(EF).PA and EF are assembled into edema toxins,PA and LF are assembled into lethal toxins.The protective antigen is not involved in the toxicological effect,and its role is mediated by other two virulence factors into the cell.EF / LF in the intracellular release and play the enzyme activity and cause cell death.There are three possible therapeutic strategies for this mechanism: 1)blocking the binding of PA to the receptor;2)blocking the assembly of toxins;and 3)inhibiting the enzymatic activity of LF and EF.So far there is no drug against anthrax toxin.Lethal factor is the main virulence factor of anthrax toxin.Therefore,the study of anthrax toxin lethal factor inhibitors,and the development of anti anthrax lethal toxin drugs,is an urgent need for national security and stability.Several classes of chemically distinct classes of LF inhibitors have beenidentified in worldwide.In the previous studies of this project,we designed and synthesized a series of LF inhibitors by analyzing the structural characteristic of LF active site and discloesd LF inhibitors.The evaluation methods of LF inhibitor,including binding assay,cell and animal model,were established.Some of those compounds showed activity against rathrax LF in low micromolar to nanomolar concentrations and one of them was identitied with significant activity in the rat anthrax LT challenge model.On this basis,we analyzed the structural characteristics of each compound,and further designed a series of new structures of the target compounds.Five synthetic routes were designed for the synthesis of these target compounds,and 47 target compound molecules were synthesized using these synthetic routes.These compounds have not been reported in the literature,and their structures are confirmed by 1H-NMR and LC-MS.In the process of synthesis of the target compounds,the reaction conditions of each step including in the synthetic strategies was investigated in detail.Especially a suitable synthetic method of each intermediate was found in the research.Determination of inhibitory activity of target compounds on LF cleavage MAPPKide polypeptides by fluorescent peptide fragmentation test.The results showed that the inhibitory activity of anthrax-induced lethal factor(LF)was greater than that of the positive drug ?-1,?-6,?-1,?-3,?-6,?-7,?-1,?-4,?-6,?-7,?-8,?-13,?-1,?-2,?-3,?-4,?-5,?-6,?-7,?-9,?-11 and ?-4;the percent inhibition rate was similar to that of the positive drug ?-3,?-5 and ?-12;the percent inhibition rate waslower than that ofthe positive drug ?-2,?-3,?-4,?-5,?-7,?-2,?-4,?-5,?-8,?-9,?-10,?-11,?-2,?-9,?-10,?-11,?-8,?-10,?-12,?-1,?-2 and ?-3.According to the results of the preliminary activity evaluation,the SAR ofthe target compounds was analyzed.These conclusions will give a foundation for the structural optimization of theseanthraxlethal factor.