2,3-Dioxoindolin Phenylacetamide Derivatives:Synthesis,Potent CDC25B Inhibitors

Isatin（ISA）,also known as 2,3-indole diquinone,is an important natural product widely distributed in animals,plants and humans,and it is highly distributed in the hippocampus and other parts of the brain,meanwhile it is also an endogenous active factor for the survival of marine animals such as lobsters.So far,it has been reported that isatin and its derivatives have varieties of biological activities with hypotoxic such as antitumor activity,antivirus activity,neuroprotection and antioxidation.Furthermore,the biological mechanisms of phosphatase CDC25B and PTP1B were gradually revealed,which were the new targets for tumor drug research.In order to find a new antitumor isatin derivative with high activity and low toxicity,we designed and synthesizedtwo series of 27 isatin derivatives used substituted aniline as the starting material.The inhibitory activity of these derivatives against CDC25B and PTP1B enzymes were evaluated,and the structure-activity relationship was analyzed.The compounds synthesized in this study were divided into two series:the first series of 15 isatin derivatives（4a-4o）were obtainedby Sandmeyersynthesis method and modified by amidation reaction with 2-chloro-N-phenylacetamide while substituted anilineas was used as the starting material,thin layer chromatography（TLC）was used to detect experiments,and the compounds were purified by recrystallization.The inhibitory activity of these derivatives against CDC25B and PTP1B enzymes were evaluated.The second series of 12 isatin derivatives（5a-5p）were obtainedby Sandmeyersynthesis method and modified by amidation reaction with substituted 2-chloro-N-phenylacetamide while anilineas was used as the starting material,TLC was used to detect experiments,and the compounds were purified by recrystallization.The inhibitory activity of these derivatives against CDC25B and PTP1B enzymes were evaluated.Results showed that:In the first series,most of derivatives showed inhibitory activity against CDC25B（IC50=3.2-23.2μg/mL）and PTP1B（IC50=2.7-21.4μg/mL）.Compound4h showed the most inhibitory activity in vitro with IC₅₀ values of 3.2 and 2.7μg/mL against CDC25B and PTP1B,respectively.In cytotoxic activity assays compound 4h had potent activity against HeLa,A549,and HCT116 cell lines.In addition,compound4hshowed potent tumor inhibitory activity in a colo205 xenograft model in vivo.In the second series,most of the compounds showed potential inhibitory activities for CDC25B and PTP1B.Among them,compound 5k displayed the most potent inhibitory activity against CDC25B and PTP1B(IC₅₀=3.87μmol/L and 2.98μmol/L,respectively).The compound 5k also exhibited higher cytotoxic activity against three cancer cell lines（HeLa,A549 and HCT116）.In addition,the compound 5k revealed the potent tumor inhibitory activity in a colo205 xenograft model in vivo.Main conclusion:two series of isatin derivatives were synthesized by introducing different substituted groups to the parent nucleus and its 1-N atom based on the lead compound isatin,and related research on their inhibitory activities for CDC25B and PTP1B were tested.The antitumor activity was preliminarily evaluated,and the structure-activity relationship was discussed,meanwhile the antitumor activities of compounds 4h and 5k were evaluated in vitro and in vivo,which provided a basis of theory for a new class of antitumor with signifcant biological activity and less toxic side effects.