A Study On The Extraction And Isolation Of Bioactive Constituents From The Leaves Of Eucommia Ulmoides

Based on the small-scale test study, bioactive constituents were isolated and purified from leaves of Eucommia ulmoides Oliver in a pilot-scale experiment by the previous process, some technical conditions were ameliorated according to its demands, and finally, the proper technological procedure of pilot-scale experiment was proposed. The results are as follows.The proper technological procedure of pilot-scale experiment can be summarized as: reflux the leaves by 60% ethanol(80℃,2h,rate of material to solvent: 1:16 ,3 times)→extracts preparation(concentrate, Vacuum drying at 50℃)→extract by water(4 times)→load the extract on the XDA-6 resin column→elute with pure water for sugar and geniposidic acid→elute with 15% ethanol for chlorogenic acid→elute with 50%～70% ethanol for flavonoids→resin's regenerationThe detailed main operating points are as follows.1. Extraction: refluxing the leaves by 60% ethanol was adopted in the pilot-scale experiment. 6kg leaves put in 96L 60% ethanol were extracted under reflux 3 times (2h each time) at 80℃.The raffinate was concentrated under vacuum into extract. The yield of extracts obtained is 39.78%; the content of total sugar in the extracts is 32.62%, geniposidic acid is 1.57%, chlorogenic acid is 6.42% and flavonoids is 6.82%.2. Loading to the column: the extracts which was then dissolved in cold water and filtered. The filtrate was concentrated to 0.46g/mL, and regulated pH 2～3with hydrochloric acid, and then loaded the extract on the XDA-6 resin column ofΦ200×1500mm.Elute after static absorption 8h.3. Eluation: the resin column was eluted with pure water at first, collect the lotion of first two cubage for sugar and collect after the 3th cubage for geniposidic acid; eluted with 15% ethanol for chlorogenic acid; eluted with 50%～70% ethanol for flavonoids. After separated by the XDA-6 resin, total sugar content in the solid state of the fraction 1 of water eluant is 50.35%, with a yield of 22.48%; geniposidic acid content in the solid state of the fraction 2 of water eluant is 22.74%, with a yield of 1.23%; chlorogenic acid content in the solid state of the eluant of the 15% ethanol is 32.06%, with a yield of 3.97%; the content of flavoniods in the eluant of 60% ethanol is 29.89%, with a yield of 4.44%.4. There was no significant difference in the content of bioactive constituents which obtained by new and regenerated XDA-6 resin except chlorogenic acid. The content of chlorogenic acid isolated by regenerated resin can reached to 46.35%, was higher than isolated by new resin. Chlorogenic acid was purified by direct recrystallization.It was proved that the technological process was feasible.In addition, due to omit the procedure of solvent extraction, the process are simplified.Materials and primary reagent consumption used in the whole study:Eucommia ulmoides leaves: 6kg; XDA-6 resin: 20kg.Purified water: 540L, 95% ethanol: 80L, HCl: 5L, NaOH: 3600g (isolated by new resin,); purified water: 540L, 95% ethanol: 80L, HCl: 5L, NaOH: 3600g (isolated by regenerated resin)The feasibility of industrial production was studied according to production facilities condition and production period, the result showed that production equipments were easy to get and the period of production was short.