Study On The Purification Process Of Reserpine And Yohimbine From Rauvolfia Vomitoria

Rauvolfia vomitoria, an important plant as medicine resource, contains many kinds of alkaloids, such as reserpine and yohimbine. Reserpine acts steadily and permanently in hypertension therapy. Yohimbine is widely used to cure erectile disfunction, arteriosclerosis and rheumatism.According to present purification process of reserpine, this paper investigated a purification process of reserpine and yohimbine from same material of R. vomitoria.The determination conditions of reserpine and yohimbine by HPLC were studied. Stepwise elution could determine reserpine and yohimbine respectively. Acidic water containing ethanol was applied to extract reserpine and yohimbine from root powder of R. vomitoria. Suitable conditions were selected by orthogonal experiments. The extract was adsorbed by HZ-818 macroporous resin. Reserpine and yohimbine were eluted separately by different concentration of ethanol. Then they were purified and crystallized respectively.Reserpine in elute was purified through a series of processes including precipitation of alkaloids, crystallization and recrystallization. The purity of reserpine was 99.8% and the recovery yield was 27.1%.The yohimbine content of Rauwolfia vomitoria was low and the interference in purification from impurities was severe, so many difficulties were met during separation of yohimbine. Crude yohimbine was used to study several methods for yohimbine purification, then the yohimbine elute of R. vomitoria was used for experiments. Methanol extraction and crystallization only got low purity and recovery yield of reserpine, which was not applicable. Reversed phase chromatography by C-18 could raise purity of reserpine to 41.8%, but C-18 medium was expensive so that it could not be applied in production. Ether extraction and crystallization could get 4.9% yohimbine purity and 9.8% recovery yield, which was better than other two methods, but was not satisfactory. Further investigation is necessary for establishing a process to purify reserpine and yohimbine from R. vomitoria with low cost, high recovery and high purity. It will be beneficial to utilize medicinal materials fully and raise economic effect highly.