Studies On Quinoline-based Benzimidazole Heterocyclic Antitumor Compounds

Quinoline derivatives and 2-oxo-quinoline derivatives exhibits a variety of outstanding biological activities,including antifungal,anti-inflammatory,antimalarial and antitumor.So the design and synthesis of new quinoline derivatives and 2-oxo-quinoline derivatives with better antitumor activity has attracted many chemists’ interest.In addition,as a significant versatile bioactive moiety,many benzimidazole derivatives have shown good antitumor activity.It is thus to expected that the inducing of benzimidazole groups to quinoline and 2-oxo-quinoline cores may lead to better antitumor activity.We synthesis of new 2-chloro-quinoline-benzimidazole derivatives and 2-oxo-quinoline-benzimidazole derivatives and we study its antitumor activity and mechanism which compounds exhibited high inhibitory activity in vitro and in vivo.The main contents are as follows.1.Firstly,Introduces the progress and achievements of antitumor drugs,summarizes the antitumor research progress on Quinoline derivatives,2-oxo-quinoline derivatives and benzimidazole derivatives.On this basis,this paper expounds the significance of the topic and the research content.2.We have synthesized twenty four 2-chloro-quinoline-benzimidazole derivatives and twenty four 2-oxo-quinoline-benzimidazole derivatives through organic synthesis method.The structure of each compound was characterized by HRMS,1H NMR and 13C NMR in order to make sure all of the compounds were right.3.The in vitro antitumor activity of each compound against NCI-H460,BEL-7404,SK-OV-3,Hep-G2 and HL-7702 cell lines were tested by MTT method.According to their IC50 values,all compounds displayed lower inhibitory rates than 5-Fu against the normal liver cells,HL-7702.Compounds 3c,3e,5c on Hep-G2 cells exhibited the higher inhibitory activity,the IC50 values is 7.54μM,7.59μM and 8.45μM.However,compounds 3c,3s shows the higher inhibitory activity to SK-OV-3 cells,the IC50 values is 9.4μM and 8.83μM.Compound 5u performance the higher inhibitory activity to BEL-7404 cells,the IC50 values is 9.06μM.Using flow cytometry to detecte the effect of 3c,3e,5c on the cell cycle and apoptotic of Hep-G2 cells,the effect of 3c,3s on the cell cycle and apoptotic of SK-OV-3 cells and the effect of 5u on the cell cycle and apoptotic of BEL-7404 cells.The results show that these cells were treated with the compounds,respectively appeared apoptotic phenomenon and these compounds make the corresponding tumor cells be arrested in G2 phase.4.Using fluorescence microscopy to detect Hoechst 33258 to detect apoptotic cells.The results show that the compounds 3c, 3e,5c can induce the Hep-G2 cells apoptosis,the compounds 3c,3s can induce the SK-OV-3 cells apoptosis and the compounds 5u can induce the BEL-7404 cells apoptosis.5.Using fluorescence microscopy to detect the decrease of mitochondrial membrane potential(JC-1),intracellular reactive oxygen species (ROS) level changes and intracellular Ca2+ level changes.The results show that the tumor cells were treated by corresponding the compounds,the level of ROS in the cells was increased,calcium ion release,resulting in the decrease of mitochondrial membrane potential,enhanced membrane permeability,and then induced apoptosis.It’s explain that the compounds of inducing apoptosis is associated with mitochondrial pathway.6.Western Blot experiments were used to analyze the expression of key proteins in the related regulatory pathway,the results revealed that the Hep-G2 cell were treated by the compounds 3c and 5c,Bcl-2 expression was down-regulated while p53,Bax,and Cytochrome C expression levels were strikingly increased,thereby activating the Caspase-9,further activate Caspase-3.The experiment proved complexes by mitochondrial apoptosis pathway induced apoptosis in Hep-G2 cell.The compounds 3c and 5c caused cell cycle arrest in G2 phase by upregulating p53,p27,p21,protein,and thus reduced cdc25c,CDK1,Cyclin B1 protein.7.We also find that compounds 5c and 5u shows the higher antitumor activity in vivo,especially the compound 5c,it possessed significant antitumor activity in NCI-H460 xenograft mouse model with an inhibitory rate of 66.9% and higher in vivo safety than cisplatin.It provide a theoretical for finding such the good effect and small toxicity antitumor drugs.