Extraction Process Of Ursolic Acid From Hedyotis Diffusa. Willd

Ursolic acid is triterpenoid compound that exist widely in medicinal herbs and other plants. In the first chapter of this paper, the analysis, extraction, purification and pharmacology of ursolic acid were reviewed. These corresponding study of ursolic acid from the Chinese herb Hedyotis diffusa.Willd were included in later chapters.A HPLC method for determination of ursolic acid in was established. A C18 column was used with the mobile phase of methanol-water-acetic acid (85:15:0.3,v/v) at the UV detection wavelength of 210nm;the flow rate was 0.6ml/min.To optimze the conditions for the extraction of ursolic acid from Hedyotis diffusa.Willd., extraction was studied by single factor and orthogonal experiment guided by the recovery of ursolic acid. Results showed that the successive order of factors affecting extraction was: extraction time> extract times> alcohol concentration> solid-liquid ration. The optima conditions for extraction of ursolic acid were determined to be 95% alcohol at 85 ℃ in 1.5h for twice and solid to liquid ratio 1:8.Later the product was degreased by petroleum ether thrice, and then extract by chloroform. Dissolved the extract in 10% NaOH alcoholic solution at pH=ll, filtrated, acidficated the filtrate by 10% HC1 alcoholic solution at pH=2, and then diluted the solution by adding water with the same pH. Filtrated, washed the filter residue to neurtral, and dried the product. After these steps, ursolic acid had been concentrated effectively. The purity of ursolic acid was above 35% and the recovery yield was above 70%.In chapter 5 the technic of ursolic acid purification by silica gel columnchromatography was discussed. The composing of mobie phase, the type of silica gel, flow rate, temperature etc fators were taken into account. The optimal techincs was described as follow: chooseing silica gel as stationary phase, and chloroform-methanol system as mobile phase in a gradient mode with flow rate 0.8BV/h;the temperature should be controlled below 30℃. After crystalization, the last product purity was 71%.The pharmacology of the product was tested by MTT on the cell of K562/ADM . It was found that the product restrained the proliferation of cells effctively.