Analysis, Isolation And Synthesis Of Several Pentacyclic Triterpene Acids

Oleanolic acid (OA), Ursolic acid (UA), Corosolic acid (CA) and other pentacyclic triteipenoid acids exist in many Chinese herbs, such as Fructus Ligustri Lucidi, Folium Eriobotryae and Prunella vulgaris. These compounds have a wide range of applications in clinic treatment for their effectiveness in blood-glucose regulation, liver protection and antitumor therapy. Therefore, it is of vital importance to study the extraction, analysis, preparation and chemical synthesis of these pentacyclic triterpenoid acids.In this thesis, the qualitative and quantitative analyses of Fructus Ligustri Lucidi (FLL) from the Oleaceae family are carried out with near-infrared spectroscopy (NIRs).120NIRs spectra of nine alcohol-broiled products and one crude sample from eight different areas are collected. After the qualitative discrimination through factorization algorithm and pretreatment of second-derivative (2-Der), the qualitative model is testified to be efficient in distinguishing FLL samples from different origins (eight producing areas), alcohol-broiled products and crude products. Based on the partial least squares (PLS) algorithm on OA and UA in FLL. the quantitative models are established with optimum parameters. There is no significant difference between the observed values for NIRs and HPLC method since the results of correlation coefficients (R2), root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP) for OA are99.53%,0.502mg/g and0.800mg/g respectively; and those of the UA model are97.82%,0.242mg/g and0.283mg/g. As a result,the established NIRs method in this paper is applicable to the rapid qualitative and quantitative analyses of active ingredients in FLL,Folium Eriobotryae is one of the main sources of CA、UA and OA for its richness in various kinds of pentacyclic triteipenoid acids.In this paper, Centrifugal Partition Chromatography (CPC) and preparative high performance liquid chromatography (pre-HPLC) are utilized to separate pentacyclic triterpenoid acids. With the application CPC technique of ethyl acetate-n-hexane-methanol-water solvent system, CA is acquired at22min in the separation experiment. With methanol-0.4%phosphoric acid (80:20, v/v, pH=6.5, adjusted by triethylamine) being the mobile phases,CA、UA and OA are separated by the pre-HPLC with high purity and the separating value level is0.1g. The difference between honeyed Folium Eriobotrya and the crude product is studied by comparing the contents of three triterpene acids. Though the contents of triterpene acids in honeyed Folium Eriobotrya are large, its withdrawal rates are low for it can be adsorbed easily in the purification process.2β,3a-dihydroxyurs-12-en-28-oic acid is a naturally occurring diastereoisomer of corosolic acid, with good glycogen phosphorylase inhibitory activity, but low content in plants. Using the commercially available ursolic acid as the starting material,2β,3α-dihydroxyurs-12-en-28-oic acid was synthesized through five facile steps with high stereoselectivity and an overall47.3%yield. Besides, the study determineds the stereochemical structure of the product through optical rotation, ESI-MS,’H and13C NMR data. This synthesis method is proved to be more efficient by shortening the reaction route and enhancing the productivity compared to the previous methods, providing guarantee to the follow-up study on this chemical compound.