Design,Synthesis And Anti-tumor Activity Of Tetrandrine Derivatives

Objective:In this paper,based on the literature research and the preliminary research of the research group,we continue to modify the structure of the natural active ingredient tetrandrine,and investigate the in vitro anti-tumor activity of its derivatives.It is hoped that new derivatives with better anti-tumor activity will be obtained,which will provide a structure-activity relationship analysis.The mechanism of inducing cell apoptosis of representative preferred compounds was studied to explore the anti-tumor mechanism of derivatives of tetrandrine as the lead compound.Methods:In this study,Tetrandrine as the lead compound,in the system of concentrated nitric acid and acetic anhydride as nitrification reagent for the synthesis of high purity and good yield of intermediate C-14 nitro tetrandrine T₁,and then through the catalyst palladium carbon,hydrazine hydrate as reducing agent system synthesis of high purity of intermediate C-14-amino tetrandrine T₂.Under the catalysis of copper acetate and different boric acid compounds,twenty new Tet derivatives were obtained by Chan-Lam-Evans coupling reaction.During the process,the effects of material ratio,reaction temperature,catalyst type,alkali type and other conditions on product yield were investigated.The structure was confirmed by HRMS,¹H NMR and ¹³C NMR.The antitumor activities of the twenty derivatives were screened in vitro.Tetrandrine and doxorubicin were used as controls to select the target compounds with better activity and less toxicity against HepG2 cells,A549 cells and HL7702 cells.Results:In this study,the optimization process for the synthesis of TET derivatives by Chan-Lam-Evans coupling reaction is as follows,the material ratio C14-amino-tetrandrine and boric acid（1:2）,copper acetate and pyridine were added to the solution of CH₂Cl₂at room temperature.Stirring reaction in dry oxygen atmosphere for 12-24 hours to complete the reaction and the yield of the product is improved.The structure identification spectrum analysis showed that the structures of the twenty compounds synthesized in this study were consistent with the target compounds,and none of them had been reported in the literature.Determined by MTT antiproliferative activity in vitro test results show that,for HepG2（liver cancer cell）,A549（lung cancer cell）,synthesize the derivatives of the inhibition rate were greater than 50%,and lead compounds IC₅₀alue concentration of Tet,except the compounds 1,3,12,13 all the derivatives IC₅₀alue concentration below the powder has alkali proof,and the impact on the normal hepatocyte HL7702 value-added activity there was no significant difference between various derivatives.Compound 17showed the best antiproliferative activity against HepG2 cells and A549 cells,with IC₅₀values of 2.09μmol/L and 4.45μmol/L,respectively.The antiproliferative activity of compound 17 against HepG2 cells was 5.3 times higher than that of TET and 6.4 times higher than that of adriamycin.Western blot results showed that Bax protein expression was increased and Bcl-2protein expression was decreased after compound 17 was treated with HepG2 cells for48h.The activation of Caspases leads to increased PARP cleavage and accelerates the death of apoptotic cells.Conclusion:The reaction conditions of the reaction route of nitration and amination at the C-14position of tetrandrine were screened,and 20 new bisbenzylisoquinoline compounds were synthesized.The structure of all the compounds was confirmed to be the target compound,and there are no reports in the literature.The in vitro anti-proliferative activity results show that the derivatives synthesized at this site have higher selectivity for liver cancer HepG2 cells and relatively low activity on lung cancer A549 cells.Compound 17 has good anti-proliferative activity on liver cancer HepG2 cells and lung cancer A549 cells.During the synthesis process,it was found that a strong electron withdrawing group connected to the ligand binding site is easier to synthesize and the yield is high.The preliminary structure-activity relationship results show that the activity of the derivative gradually increases with the increase of the volume of R-.When the pyridine ligand compound is introduced,the synthesized derivative has a better anti-tumor effect and is suitable for further research.Compound 17 has an inhibitory effect on the migration and invasion of HepG2 cells and is concentration-dependent;preliminary studies on the anti-tumor mechanism indicate that the synthetic derivatives may cause cell cycle arrest,change the proportion of apoptosis-related proteins,and affect mitochondria Function and so on promote the apoptosis of cancer cells.These results indicate that compound 17 may become a potential anti-cancer drug.These findings provide a scientific reference for the future design and development of more effective anti-tumor drugs for the treatment of liver cancer.