Design,Synthesis And Biological Activity Evaluation Of 2,4,6-Trimethoxychalcone Derivatives

Natural products are one of the most important sources for new drug development on account of their variety,novel structure,and wide range of biological activities.According to statistics,more than 60%of the new chemical entities approved worldwide from 1981 to 2014,which belong to natural products or natural product derivatives,especially in the research fields of antibiotics,antineoplastic drugs.From 2012 to 2021,the number of new drugs approved by the FDA had a decreasing trend year by year,but approvals for related drugs from natural product sources remain stable.Therefore,natural products remain an important source for new drug development,opening a door for the discovery of innovative drugs with developmental value.Chalcone compounds are the main active ingredients of many medicinal plants and are widely distributed in various vegetables,fruits,teas,and other plants,such as Akebia,distended fruit licorice,tree pepper,celery,and so on.However,the natural compounds extracted and isolated from plants also have shortcomings,such as complex structures and a large number of chiral centers,which are difficult to synthesize,and it is difficult to isolate and purify newly discovered natural products to meet the needs of modern natural product new drug development.Given,chalcone has a simple structure,easy synthesis,and a large number of substitutable hydrogens on the aromatic ring,it is widely used as an effective template for the discovery of new drugs.In this study,A,B and C series of 2,4,6-trimethoxychalcone derivatives were designed and synthesized based on the collocation to obtain the lead compound A7,and screened for antibacterial and antitumor activity,and reverse molecular docking to predict the target of action.The research is divided into the following sections.（1）Design and synthesis of 2,4,6-trimethoxychalcone derivativesIn the early stage,our group designed and synthesized a large number of derivatives around phloroglucinol,and found that the butyryl phloroglucinol compound have good antibacterial and antitumor activities.However,the phenolic hydroxyl groups on phloroglucinol are easily metabolized and removed in vivo,and methylation protection of the hydroxyl groups can slow down the metabolism in vivo and enhance the activity.Given the similarity between the backbone of 1-（2,4,6-trimethoxyphenyl）butan-1-one and chalcone,we designed and synthesized a series of novel chalcone derivatives based on a series of conformational exploration,backbone leap and spatial exploration of the obtained molecules.The absorption,distribution,metabolism and excretion（ADME）related properties of the compounds were predicted,and the purity of the synthesized compounds reached over 97%by high performance liquid chromatography.（2）Antibacterial activity of 2,4,6-trimethoxychalcone derivativesThe antibacterial activities of the compounds of series A,B,and C were determined by the micro-broth dilution method against four Gram-positive bacteria（methicillin-resistant Staphylococcus aureus,Staphylococcus albus,Staphylococcus aureus,and Bacillus subtilis）and two Gram-negative bacteria（Escherichia coli and Pseudomonas aeruginosa）.The results of the study showed that the compounds did not inhibit Gram-negative bacteria,and some of them inhibited Gram-positive bacteria.（3）Antitumor activity study of 2,4,6-trimethoxychalcone derivativesThe A,B,and C series of compounds were screened for their inhibitory effects on four tumor cells（hepatocellular carcinoma cells,Hep G-2;non-small cell lung cancer cells,A-549,breast cancer cells,MCF-7;cervical cancer cells,Hela）by MTT cytotoxicity assay.The results showed that the compounds had broad-spectrum antitumor activity,and most of them had stronger antitumor activity than the positive control5-Fu,Compound B3 showed the strongest inhibitory effect on Hela cells(IC₅₀=3.204μM)and Mc F-7 cells(IC₅₀=3.849μM),which was 10times higher than that of positive control.Several representatives compounds B1-B4,B10,B14-B16 were selected to study the toxicity to normal hepatocytes,and the compounds were less toxic to normal cells in a certain concentration range.The efficacy of compound B3 on Hela and MCF-7 cells was demonstrated by time-dependent assay,scratch assay,and cell cloning assay,which demonstrated that compound B3 could effectively inhibit the migration and value-added of tumor cells.Finally,the study on the effect of compound B3 on apoptosis of Hela cells revealed that compound B3 had a pro-apoptotic effect on tumor cells.（4）Reverse molecular docking to predict possible targets of actionIn this study,compounds B1-B4,B10,and B16 were selected as small-molecule ligands and 20 proteins essential for tumor growth and survival as receptors for molecular docking studies.The docking scores,three-dimensional and two-dimensional interaction patterns showed that six small molecule compounds had strong interactions with CDK1 and fully occupied the protein pocket groove.Therefore,we predict that the target of this class of chemotaxis may be a cyclin-dependent kinase CDK1 and the mechanism of action may be related to cell apoptosis.