• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.157-162
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• 2012

In this study, we have for the first time applied increased surface area fractional precipitation in order to decrease the particle size of the anticancer agent paclitaxel from plant cell cultures. When compared with the case where no surface area increasing material was employed, the addition of ion exchange resin as a surface area increasing material resulted in a considerable decrease in the size of the paclitaxel precipitate. When ion exchange resin was used, the paclitaxel particles were four to five times smaller, having less than a 20 ${\mu}m$ radius, than those obtained in the absence of ion exchange resin. This is presumably because the growth of paclitaxel particles was impeded by the addition of ion exchange resin. The size of the paclitaxel precipitate also depended on the material used to increase the surface area, a result considered to be due to differences in the affinity between the particular ion exchange resin used and the paclitaxel particles. The yield of paclitaxel was significantly improved when ion exchange resin was used as a material to increase surface area. Paclitaxel, with a reduced particle size due to the addition of a surface area increasing material during the fractional precipitation process, is believed to be particularly useful for practical applications of the drug.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.114-120
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• 2014

This study evaluated the effect of the zeta potential of silica-alumina on the behavior, in terms of purity, yield, fractional precipitation time, precipitate shape, size of fractional precipitation in the increased surface area, and the fractional precipitation process, for the purification of paclitaxel. As the zeta potential value of silica-alumina increased, the yield of paclitaxel concurrently increased while the precipitation time decreased. The use of alumina with the highest value of the zeta potential (+35.41 mV) as a surface area-increasing material dramatically reduced the precipitation time by 12 h compared with the results of the control. On the other hand, the purity of paclitaxel had almost no effect on changes in the zeta potential of silica-alumina. In addition, the precipitate size was inversely correlated with the absolute value of the zeta potential.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.343-349
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• 2015

In this study, we applied an increased surface area fractional precipitation with hydrophilic polymer for decreasing the particle size of the anticancer agent paclitaxel from plant cell cultures. The addition of polymer resulted in a considerable decrease in the size of the paclitaxel precipitate. Among the polymers (HPMC 2910, PVP-K90, PVA) used, PVP-K90 was the most effective for the inhibition of precipitate growth. When PVP-K90 (0.2%, w/v) was used, the paclitaxel particles were four to five times smaller, having less than a $20{\mu}m$ radius, than those obtained in the absence of the polymer. In addition, the precipitate size was inversely correlated with the absolute value of zeta potential.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.831-835
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• 2015

This study evaluated the influence of the zeta potential of silica-alumina on the behavior in terms of purity, yield, and precipitate shape and size of fractional precipitation in the fractional precipitation process for the purification of (+)-dihydromyricetin. The optimal silica-alumina amount (surface area per working volume of reacting solution) for zeta potential control was $100mm^{-1}$. As the zeta potential value of silica-alumina increased, (+)-dihydromyricetin yield and precipitate size were increased. The use of silica with the highest value of the zeta potential (+4.99 mV) as a zeta potential-controlling material increased the (+)-dihydromyricetin yield by 2-fold compared with that of the use of alumina with the lowest value of the zeta potential (-19.00 mV). In addition, the (+)-dihydromyricetin yield and precipitate size was inversely correlated with the absolute value of the zeta potential. On the other hand, the purity of (+)-dihydromyricetin had almost no effect on changes in the zeta potential of silica-alumina.