Synthesis And Characterization Of Ursolic Acid And Glycyrrhetinic Acid Derivatives, And The Study On The Anti-bacterial Activity

Ursolic acid and Glycyrrhetinic acid are pentacyclic triterpenoid compounds, which are the main functional compositions of many natural products. It exhibits varieties of biological activity, including anti-bacterial, anti-tumor, anti-HIV, hepatic protected and many other pharmacological effects. Because of its low toxicity, wide range of pharmacological activity, scientists do many researches on ursolic acid and glycyrrhetinic acid about its pharmacological activity. We have always been engaged in the research work.Ursolic acid and Glycyrrhetinic acid have been widely used on clinic, but the low water-solubility confines the application. In order to improve water- solubility of these compounds, amino acids were introduced to the lead compounds. And then, we converted the derivatives of good biological activity into ammonium form.As the constructional unit of human proteins, amino acids are essential nutrients. Introduction of amino acids on the lead compounds do not increase the side effects, which can improve the capability of target location and bioavailability to a large extent.This dissertation adopts the splice theory used in drug development. We combine several compounds of good biological activity into one part so as to get drugs of better biological activity.In this paper, our research work contains three parts:Firstly, we mainly describe the biological activity of ursolic acid and glycyrrhetinic acid, respectively, and give a brief introduction of amino acid and amino- protecting groups.Secondly, we designed twenty derivatives of glycyrrhetinic acid and ursolic acid. And, by modifing ursolic acid and glycyrrhetinic acid we obtained 20 pentacyclic triterpenoids derivatives in sum.Thirdly, the pentacyclic triterpenoid compounds obtained were studied by the antibacterial activity.