Design, Synthesis And Antitumor Activity Of 3-substituted-5-aryl Indazole Derivative

Indazoles are an important class of nitrogen-containing heterocyclic compounds.The different substituted indazoles are of great interest for their various biological activities such as antitumor,anti-inflammatory,antibacterial,antidiabetic and anti-osteoporosis,and are widely used in drug molecular design in view of their excellent pharmacological activities.In this thesis,two series of compounds,totaling 38 novel 3-substituted-5-aryl indazole derivatives,were synthesized by introducing the reactive groups mercaptoacetamide and piperazine acetamide into the indazole molecule,respectively,using indazole as the parent nucleus,and the molecular structures of the target compounds were characterized and confirmed by ¹H NMR,¹³C NMR and HRMS（ESI）.Firstly,the in vitro anti-proliferative activities of the target compounds against human chronic myeloid leukemia cells K562,human lung cancer cells A549,human liver cancer cells Hep-G2 and human prostate cancer cells PC-3 were determined by MTT（Methyl thiazolyl tetrazolium）assay,and the cytotoxicity of the highly active compounds against normal human embryonic cells HEK-293 was also determined.Subsequently,the conformations relationships were explored based on the assay results.The results showed that among the two series of compounds,5a-5q and 6a-6u,compound 5k showed the optimal inhibitory activity against Hep-G2 cells and compound 6o against K562 cells with IC₅₀ values of 3.32±0.43 and 5.15±0.55μM,respectively,which were superior to the positive control drug 5-Fu（5-fluorouracil）.Subsequently,the cytotoxicity of 5k and 6o on normal human embryonic kidney cells HEK-293 was checked to evaluate the compound safety and selectivity.The results showed that compound 6o was 6.45 times more selective against the K562 cancer cell line than the normal cell line HEK-293(IC₅₀=33.2±3.83μM),while 5k cells had a lower safety profile(IC₅₀=12.17±2.85μM).Subsequently,we found that compound 6o was in a position to promote apoptosis in K562 cells in a time-and concentration-dependent manner and induce cell cycle arrest in the G0/G1 phase.In addition,the effects of compound 6o on the expression levels of apoptosis-related proteins Bcl-2,Bax,P53/MDM2 and Bcr-Abl,an essential protein associated with chronic myeloid leukemia,were examined.The results showed that compound 6o may increase P53 protein expression by inhibiting Bcr-Abl expression and ultimately induce apoptosis in K562 cells by suppressing MDM2 protein expression,and unregulated Bcl-2,down regulating Bax protein expression.