The Design,Synthesis And Bioevaluation Of Colchicine Binding Site Inhibitors Containing Triazole Scaffold

Colchicine binding site is one of the important binding sites of microtubuledestabilizing agents,and its inhibitors play a dual role in anti-proliferation and vasculardisrupting activities,resulting in nearly thirty colchicine binding site inhibitors(CBSIs)been in the clinical research.CBSIs usually have the characteristics of significant structural diversity,small molecular weight and easy to modification,thus they afford adequate space for structural optimization to improve activity,water solubility and metabolic stability.4-Substituted methoxybenzoyl-aryl-thiazoles(SMART),reported by Miller group,were colchicine binding site inhibitors with outstanding activity based on natural products.SMART against several cancer cells with IC50 values in the sub-micromolar level,prevented the formation of microtubules and cell mitosis effectively by inhibiting the polymerization of tubulin.However,the thiazole ring of SMART may undergo oxidization,produce nitrogen oxides and break down,resulting in its reduced stability in vivo.Moreover,the carbonyl group of SMART is easily to metabolism reduction and further reduced its metabolic stability.Furthermore,most of the SMART compounds have poor water solubility.In addition,Conformational studies indicated that the "bent"conformation of SMART is necessary to maintain the antiproliferative activity.The structural features and structure-activity relationships(SAR)of SMART analogs have been summarized in this thesis.On this basis,a series of 2-aryl-4-arolyl2H-1,2,3-triazols(Ⅰ)were designed and synthesized as anti-tubulin agents which the thiazole ring of SMART was replaced by 1,2,3-triazole with better structural stability using bioisosterism strategy and 5-amino group introduced into the 1,2,3-triazole,further modification was carbonyl link between A and B ring.On the basis of target compounds Ⅰ,a series of 2,8-diaryl-2,6-dihydro-[1,2,3]triazolo[4,5-e][1,4]diazepin5(4H)-one(Ⅱ)were designed and synthesized which conformational restriction strategy is used to maintain the "bent" conformation by covalent bond,and the"privileged structure" of diazepine is introduced.Moreover,on the basis of the target compounds Ⅰ,a serious of 2-aryl-4-arolyl-5-alicyclic amine-2H-1,2,3-triazols(Ⅲ)were designed and synthesized to improve the water solubility by the restriction of the"bent" conformation with the large hindrance lipocycloamine.In vitro antiproliferative activity against three human cancer cell lines(gastric adenocarcinoma SGC-7901 cells,lung adenocarcinoma A549 cells,fibrosarcoma HT1080 cells or cervical carcinoma HeLa cells)was determined using a standard MTT assay.Most of the target compounds exhibited moderate to potent antiproliferative activity.The SAR of target compounds were summarized based on antiproliferative activity results in vitro.The selectivity of Ⅰ-1-1,Ⅰ-1-10 and(Z)-Ⅰ-3-1 to human cancer cell lines and non-cancer cell lines were elucidated by using normal fibroblast L929 cells.In order to verify target compounds,compound(Z)-Ⅰ-3-lwas evaluated for their effects on tubulin polymerization and the inhibitory effect of compounds(Z)-Ⅰ-3-1 andⅡ-11 on microtubule polymerization at cellular level were futher investigated.In addition,whether compounds(Z)-Ⅰ-3-1 and Ⅱ-11 could effectively prevent cell cycle arrest in G2/M phase and induce apoptosis were evaluated.Finally,molecular docking was carried out to study its effect on microtubule polymerization at molecular level.