Design Synthesis And Activity Evaluation Of 5-flourouracil Phosphoramidate Derivatives As Antitumor Agent

5-Fluorouracil?5-FU?is an antimetabolize antitumor drug of pyrimidine,it is widely used in the treatment of various solid tumors such as gastrointestinal cancer,breast cancer,urogenital system epithelial cancer and head and neck cancer.But its transient half-life of plasma,nonspecific cytotoxicity,and low efficiency of tumor tissue distribution can lead to severe toxic and side effects,such as myelosuppression,gastrointestinal adverse reactions,central neurotoxicity,and cardiac toxicity,and so on.Researchers have been committed to finding or designing new targeted 5-FU derivatives that are low toxic to normal cells,although many successful clinical 5-FU derivatives have made great progress in the antitumor effect and selectivity,the problem of continuous development of drug resistance is becoming a difficult problem.The modification strategy of phosphoramidate prodrugs also the existing platform technology ProTide is the important direction for the design of nucleoside prodrugs in recent decades.The nucleoside phosphoramidate prodrugs designed by ProTide technology can bypass the dependence of the active transport and kinase activation,and improve the antitumor and antiviral effect of the mother drug.At present,several nucleoside phosphoramidates are in the clinical or pre-clinical stages,including the successful listing of anti hepatitis C and B virus drugs,Sofosbuvir and TAF.In order to reduce or overcome the disadvantages generated by 5-FU based therapy,such as large toxic,side effects,low oral bioavailability and chemotherapy failure,and obtain highly active and targeted 5-FU prodrug derivatives.In this paper,by using of ProTide technology and prodrug design methods,we designed and synthesized 11mono-substituted and 13 double-disubstituted 5-FU phosphoramidate derivatives.The stability of 24 new compounds in simulated gastrointestinal fluid was studied.The results showed that most of the compounds are stable in artificial gastric fluid?plus enzyme?and artificial intestinal fluid?no enzyme?.All compounds are unstable in artificial intestinal fluid?plus enzyme?.Compared with the positive drug 5-FU and NUC-3373,CCK-8 method was used to evaluate the anti-proliferation of 24 new compounds on 7 different tumor cell lines?HT-29,HCT-116,COLO-205,MCF-7,SK-BR-3,NCI-H1975 and SKOV-3?in vitro.The inhibitory activity of compounds on different tumor cells is different,which is characterized by complexity and variability:in vitro,the tumor suppressor effect of the mono-substituted compounds is higher than that of the double-substituted compounds,and the selectivity for HCT-116,HT-29,COLO-205 and SK-BR-3 tumor plants is higher than that of MCF-7,NCI-H1975 and SKOV-3;the inhibitory effects of 131,101,103,105,107 and 109 of the mono-substituted compounds on most tumor cells were better than that of 5-FU and or NUC-3373,in which the activity of compound 131 was best,and the growth inhibitory activity to HCT-116 was nearly 8 times higher than that of 5-FU and twice higher than NUC-3373,suggesting that the ProTide side chain R₁ and R₂ are benzyl ester and naphthyl respectively in the mono substituted compounds were found to be more advantageous;in addition,when R₁ is ethyl shows better than that of isopropyl,but when R₂ is benzyl or halogen subsitituted benzyl makes little influence to activity.The above results provide a basis for the design and synthesis of new 5-FU derivatives and have further research and development value.