Design, Synthesis And Antitumor Activity Evaluation Of Betulinic Acid Derivative

BackgroundBetulonic acid,which is the one of the major effective components of many traditional Chinese medicine,has been found to possess several medicinal properties,such as antiinflammatory and anti-tumor activities.Although its content in nature is very few,it can be derived rather easily from betulin by oxidation with chromium trioxide.In birch betulin accounts for a relatively greater part in all kinds of chemical composition and obtain easily.However,a series of problems,such as poor solubility,low absorption and low bioactivity relatively,make the betulonic acid has obvious defects in clinical application.In previous study,we found that a series of derivatives which combine some active molecules of Chinese medicine with 2,3,5,6-Tetramethylpyrazine(Ligustrazine)have the advantages of stronger activity,less toxicity and better selectivity than the original molecules.In order to get some betulonic acid derivatives with better water solubility,anticancer activity and selectivity,combined the preliminary research foundation of our group with the principle of medicinal chemistry,we had introduced pyrimidine,pyridazine,pyrazines into betulonic acid molecules.Research and ResultsBased on the combination principle in medicinal chemistry and clinical application of tradition Chinese medicine,by means of chemical method,this study selected betulonic acid as the basic core and including pyrimidine,pyridazine and pyrazines.By this way,a series of betulonic acid derivatives been obtained.Regarding to biological activity,we tested those compounds for inhibiting tumor cells proliferation by MTT assay and cell toxicity to normal cells on various of tumor cells in vitro including HepG2(liver cancer cells),HeLa(cervical cancer),Bel-7402(human hepatocarcinoma),MCF-7(breast cancer cell)and MDCK(canine kidney epithelial cells).Besides,DAPI staining method explored effects of Y2C on cell nucleus change for MCF-7 cells.ResultsIn the aspect of chemistry,we had designed and syntheses 26 betulonic acid derivatives,and the structure of the compounds had been confirmed by means of 13C-NMR,1H-NMR and HR-MS,which determined the relevant physical parameters.And regarding to biological activity,the experimental results showed that most betulonic acid derivatives of four kinds of tumor cells showed good inhibitory activity,and the inhibitory effect was better than that of betulonic acid,among which Y2C showed that the promising activity of anti-tumor cells and the relatively weaker inhibitory effect on MDCK.In addition,the result of cell staining had demonstrated that Y2C could induce nuclear MCF-7 damage and cell lysis.ConclusionsIn this study,10 intermediates of pyrazines and pyrimidine had been synthesized.Besides,26 new compounds had been designed and synthesized,and the pharmacological activities of the derivatives had been evaluated.The experimental results demonstrated that it is effective to introduce pyrimidine,pyridazine,pyrazines into the C-28 of betulonic acid that enhance its inhibitory effect on tumor cells in vitro.Among them,Y2C showed a quite potential antitumor activity.This research completed the structural modification of betulonic acid,which improve its physicochemical properties,and increased its biological activity and to some degree verified that it is an useful strategy that the introduction of pyrimidine,pyridazine and pyrazines into active ingredients of Chinese herbal medicine.It provided new ideas for the development of effective ingredients of Chinese herbal medicine and traditional Chinese medicine.