| Leaves of Eriobotrya Japonica (Thunb.) Lindl. is a kind of traditional herb with antitussive effect. China is the main production country of loquat in the world. In China, loquat's plant area and production have 2/3 above of the world. It is mostly in the provinces in the south of Yangtze River. In recent years, some researchers discovered that the constituents of triterpene acids from leaves of Eriobotrya Japonica had anti-inflammatory, antihypertensive, antiviral and anti-tumor properties, and ursolic acid is the main medical constituent. In this paper, the new technology of recovering ursolic acid from the residue after extraction the essential oil and water-soluble constituents from leaves of Eriobotrya Japonica, was studied in order to give some scientific message for the comprehensive utilization of leaves of Eriobotrya Japonica. Through extraction, solution, accumulation, adsorption with Macroporous Adsorption Resin, ursolic acid with the purity of 95.10% was obtained. The main results were as following:(1) The optimal conditions determining the content of ursolic acid of the residue of leaves of Eriobotrya Japonica with high performance liquid chromatography (HPLC) method was studied. Through regulating the chromatographic pillar and flow phase, ursolic acid can almost get the complete separation with other materials, the baseline was stable and the peak form was good. A kind of analysis method with high speed and accurate degree was found out to determine ursolic acid of the residue of leaves of Eriobotrya Japonica.(2) The effect of reagent, extraction temperature, ratios of solid-to-solvent, extraction time and times of extraction on the yield of ursolic acid of the residue of the leaves of Eriobotrya Japonica when extraction by circumfluence distillation was discussed in this paper. The results of orthogonal experiment indicated that the yield of ursolic acid was 1.150% when the extracted twice by 95% ethanol at 80℃(each time the solid-to-solvent ratios was 1:14 and extraction time was 2 h).(3) The conditions of water and petroleum ether purifying the ethanol extract of the residue of leaves of Eriobotrya Japonica were studied. The results showed that the water-soluble and oil-soluble components were separated better with water (1:50) and petroleum ether (1:60, three times). After dissolving with ethanol again, the purity of ursolic acid of the extract was 14.41%, and the recovery was 95.36%.(4) The conditions of accumulating ursolic acid with acid and alkali were studied. The result was that after making the solution pH=14 with 10%NaOH, then pH=3 with 5%H2SO4, aqueous solution with pH=3 as the same volume was added. Ursolic acid was obtained with the purity of 26.33% and recovery of 88.10%.(5) XDA-200 resin as the adsorption medium was adapted to separate ursolic acid from the accumulated solution. The factors effecting on adsorption and elution were analyzed. The results were as follows: with the sample flow-rate 1.5 BV/h and concentration of ursolic acid 3.0 mg/L, the adsorption rate had arrived at 96.00% as the highest; ursolic acid was got from 90% ethanol(pH=11) of the best eluant combination with the flow-rate 1.0 BV/h and 6 BV eluant. After three times crystallization, ursolic acid was purified to 95.10%. On the basis of IR, HPLC-MS, TLC, the white crystal was identified as the ursolic acid and its purify is above 95%. The recovery of the whole process was 31.40%.(6) Compared with BHT and TBHQ at the same dosage in lard, the extract of the residue of leaves of Eriobotrya Japonica had weaker antioxidative activity by using the method of the POV value.
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