Study On Separation And Purification Of Toosendanin Extraction Solution

Cortex of Melia azedarach was utiized as raw material to extract toosendanin using soxhlet extraction. The enrichment of toosendanin was investigated through ion exchange adsorption, macroporous resin adsorption and membrane separation. The effect of working conditions on the concentration of toosendanin was widely studied. Meanwhile, the adosrption thermodyanmics and kinetics were also investigated using macroporous resin and working conditions were optimied.The use of ion exchange resin D201 for decolorization and desalination of Melia azedarach extract was widely studied. Optimized conditions were as follows: temperature 70oC, pH = 7.0, flow rate 2 BV·h-1, under those circumstances, after processing 12 BV, washed by 6BV solvent with 70% ethanol in water, toosendanin retention rate was 90.6% and the decolorization rate was 95.7%. Meanwhile, toosendanin extract concentration increased from 17.62 to 29.37%. The resin was repeated for 6 times, still preserving good performance.The experimental study of toosendanin enrichment from extracts of Melia azedarach by membrane filtration was performed using polyethersulfone microfiltration membrane with average pore size of 0.45μm. Under optimized concentration of 0.374 mg·mL-1, pH = 7.0, circulation flow rate 0.15 L·h-1, operating pressure of 0.08 MPa, temperature 35 oC, the toosendanin transfer rate was 99.2% with 6.3% impurity decrease. Microfiltration flux reached up to 147.2 L·m-2·h-1 and toosendanin concentration increased from 0.94% to 7.99%. As far as UEOS-503 ultrafiltration membrane concerned, under conditions optimized by diluting the secondary filter, toosendanin transfer rate was 92.8%, the concentration of toosendanin increased from 7.99%.to 15.22% After cleaning with various detergents, flux recovery rate for micro-filtration membrane and ultrafiltration membrane could be as high as 97.6% and 98.8%, respectively.The experimental study on enrichment of toosendanin from Melia azedarach extract by adsorption was performed over the S-8 macroporous resin. Optimized adsorption conditions are as follows: concentration of toosendanin 9.13 mg·mL-1, temperature 40oC, pH value of 8.0, the liquid flow rate of 2 BV·h-1 and processing capacity of 12 BV. Under optimum conditions in extracts of Melia azedarach the toosendanin concentration of 75.2% could be obtained. Optimized working conditions are as follows: 8 BV of 70% ethanol-water as washing solvent,pH = 6.0, temperature 40oC and eluate flow rate 1 BV·h-1.The adsorption of toosendanin over D201 ion exchange resin and S-8 resin for are in line with the Langmuir and Freundlich isotherm equation. The results showed that the ion exchange kinetics, adsorption rate over D201 resin and the rate of Lagergren adsorption equation have a good match, and adsorption rate was controlled by intraparticle diffusion. The toosendanin adsorption process on S-8 resin have a good match with the first-order kinetic equation and the intraparticle diffusion equation, influenced by the liquid film diffusion resistance and intraparticle diffusion resistance.