Synthesis And Antitumor Activity Evaluation Of Chrysin Sulfonamide Derivatives

Natural products are one of the most important sources to find new anticancer drugs.Chrysin has a preventive effect on cancer.However,there are some drawbacks that significantly limit its clinical application.The main ones are the low solubility in water,poor absorption in intestinal,the rapid metabolism of glycosylation and poor bioavailability.In a previous study,our research group found that 5-hydroxy-7-methoxy-N-(4-methylphenyl)-2-phenyl-4-oxo-4H-1-benzopyran-8-sulfonamide(compound 4a),5-hydroxy-7-methoxy-N-(3-ethynylphenyl)-2-phenyl-4-oxo-4H-1-benzopyran-8-sulfonamide(compound 4d)could inhibit the growth of HepG2 cell in vitro.The purpose of this study is to explore acute toxicity study and preliminarily investigate their mechanism of action.Firstly,this study was designed to obtain maximum lethal dose according to acute toxicity experiment.The mice were all alive after oral administration of compound 4a at 2 g/kg dosage.Due to the poor water-solubility of compound 4a,it is difficult to be absorbed into the blood stream through the stomach lining.Two strategies were employed to increase solubility.One was liquid preparation techniques,the other was chemical structure modification.The solubility of 4a in water was improved by adding latent solvent,adding surfactant and preparing microemulsion.The solubility is raised to 224.83 ?g/m L in the microemulsion system which is composed of ethyl oleate,Cremophor RH40,EtOH and H2 O with a ratio of 4.5:19.1:6.4:70(v/v%).Although the solubility of compound 4a was increased by 7493 times,it cann't satisfy the requirement of the in vivo experiment.It is necessary to continue screening prescription for enhancement of solubility.Hydrophilic groups were introduced to change the physical properties of 4a.Introduction of carboxyl and hydroxyethyl into chrysin derivatives leads to increased solubility.The antitumor activities on HepG2 cells were analyzed by MTT.The anticancer activities of these derivatives decreased in different degree,suggesting that 5-hydroxyl groups and 7-methoxyl group were the active site.Thus,more rational structural optimization based on other sites should be considered.Chrysin sulfonamide derivatives 4a,4d displayed significant antiproliferative activities on HepG2 cells.However,further studies are needed to clarify the mechanism of anticancer actions.Apoptosis of HepG2 cells was detected by flow cytometry with annexin V FITC / PI double staining.Specially,compound 4d leaded to early apoptosis in HepG2 cells.The 4d-induced early apoptotic rate was 36.94% with 3.30 ?mol / L.Meanwhile,flow cytometry revealed that compound 4a,4d significantly induced G2/M cell cycle arrest in HepG2 cells.In addition,compound 4a,4d markedly inhibited the transcriptional activity of HIF-1 in HeLa cells based on dual luciferase assay.According to flow cytometry study and HIF-1 transcriptional activity,we suspected that cyclin dependent kinase 1(CDK1)is the target of compound 4a,4d.In silico molecular docking studies showed compound 4a,4d were docked into the ATP binding site of CDK1.Inhibitory activity to CDK1/Cyclin B was evaluated by LanthaScreen Eu kinase binding assay.Compound 4a,4d had no inhibitory effect on CDK1/Cyclin B under experimental conditions.In this paper,the work on druggability and the mechanism of action is established,which lays the foundation for the following research.