Design,Synthesis And Drug-like Study Of Phosphate/Polyethylene Glycol Substituted Podophyllum Leading Compounds

Podophyllotoxin and its derivatives are a class of natural active lead compounds with anti-tumor activity,but there are problems such as increased activity,strong toxic side effects and poor water solubility.Therefore,it is necessary to modify its molecular structure to discover lead compounds with promising prospects.In the early stage,the research team has designed,synthesized and screened 4β-(6-aminopurine)-podophyllotoxin(IA-PTOX)and 4β-(5-aminocarbazole)with anti-tumor activity up to nanomolar level.Podophyllotoxin(ID-PTOX),4β-(5-fluorobenzoxazole)-4’-demethylepipodophyllotoxin(Bo-DMEP)with normal cytotoxicity up to or near millimolar,4β-(5-fluorobenzothiazole)-4’-demethylepipodophyllotoxin(Bth-DMEP),4β-S-(1,3,4-thiadiazole-2)-4 ’-Demethylepipodophyllotoxin(Thi-DMEP)and 4β-S-(1,2,4-triazol-3)-4’-demethylepipodophyllotoxin(Tri-DMEP),is expected to develope as a new anti-tumor drug with high efficiency and low toxicity.However,poor water solubility of the above compound limits the evaluation of drug properties such as in vivo efficacy and safety.Therefore,it is necessary to modify the molecular structure of these lead compounds to improve water solubility.In this study,the above compounds were used as the research object.Firstly,the structure-activity relationship was used to analyze the modification sites of 6 compounds such as 6-IA-PTOX.After the literature investigation,the phosphoric acid group with high polarity and metabolism in the body and polyethylene glycol(PEG)were selected.As a modification method,a series of new compounds were designed as target compounds.The reaction of phosphorylated substituted 4’-demethylepipodophyllotoxin derivatives synthesized with phosphorus oxychloride as a phosphate group donor and the derivatization of PEG-substituted podophyllotoxin were designed and established by chemical analysis of the target compounds.The synthesis reaction of the substance establishes a library of podophyllin derivatives.Then,the solubility and lipo-water partition coefficient(lgP)of these podophyllotoxin derivatives showed that the solubility of the phosphate-modified podophyllotoxin was about 1000 times higher than that before the modification,and lgP decreased from 5 to 0-5 before modification,which is consistent with the lipid-water partition coefficient range of most listed drugs,and has drug-like properties;The solubility of podophyllous derivatives modified with PEG was 3-10 times higher than that before modification,and lgP was about 5.5.At the same time,human hepatoma cells(HepG2),cervical cancer cells(HeLa),breast cancer cells(MCF-7),and normal liver cells(HL-7702)were used as test cells for in vitro activity evaluation,the results showed that the anti-tumor activity of phosphorylated 4’-demethylepipodophyllous derivatives was better than that of “Etopophos”.The indole activity of PEG modified podophyllous derivatives decreased,and the indole activity remained even better.In vitro solubility,lgP,and cell level activity evaluation were comprehensively screened for phosphorylated modified 4β-(5-fluorobenzoxazole)-4’-de methylepipodophyllotoxin phosphate(Bo-DMEP-P),4β-(5-fluorobenzothiazole)-4’-dem ethylepipodophyllotox-in phosphate(Bth-DMEP-P)was used as leading compounds.Finally,the results of in vivo toxicity studies showed that the two compounds LD50 was 611.27 mg/kg、600.25 mg/kg,which is expected to solve the problem of poor water solubility and strong toxicity of podophyllotoxins and develop them into potential drug candidates.The purpose of this paper is to solve the problem of poor solubility and strong side effects of podophyllotoxin.Through the design and synthesis of target compounds,in vitro solubility,lipid-water partition coefficient,cell-level anti-tumor activity and acute toxicity evaluation in mice,two screens were obtained.The lead compound Bo-DMEP-P,Bth-DMEP-P,which has improved solubility,good lg P activity and high in vitro activity,and low toxicity in vivo,lays a foundation for the development of new podophyllin drugs.