The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Jin-hyun Kim - One of the best experts on this subject based on the ideXlab platform.
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ultrasound based Fractional Precipitation for the purification of dihydromyricetin
Korean Journal of Chemical Engineering, 2021Co-Authors: Jin-hyun KimAbstract:The purification efficiency of (+)-dihydromyricetin, a bioactive plant flavonoid, was remarkably improved through ultrasound-based Fractional Precipitation. The Precipitation time (up to 30 min) taken to obtain (+)-dihydromyricetin with high purity (87.01–91.66%) and yield (90.63–92.00%) through the ultrasonic Fractional Precipitation (ultrasonic power: 80–250 W) was shortened by 40-fold as compared to the conventional method (up to 1200 min). In addition, the Precipitation rate constant was increased by 12- to 18-fold, but the activation energy was decreased to between −5,787 J/mol and −6,526 J/mol, and thereby the Precipitation rate was improved. Furthermore, the size of the precipitate was reduced by 5.1- to 5.5-fold, while the diffusion coefficient was increased by 6.4- to 6.9-fold.
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Ultrasound-based Fractional Precipitation for the purification of (+)-dihydromyricetin
Korean Journal of Chemical Engineering, 2021Co-Authors: Jin-hyun KimAbstract:The purification efficiency of (+)-dihydromyricetin, a bioactive plant flavonoid, was remarkably improved through ultrasound-based Fractional Precipitation. The Precipitation time (up to 30 min) taken to obtain (+)-dihydromyricetin with high purity (87.01–91.66%) and yield (90.63–92.00%) through the ultrasonic Fractional Precipitation (ultrasonic power: 80–250 W) was shortened by 40-fold as compared to the conventional method (up to 1200 min). In addition, the Precipitation rate constant was increased by 12- to 18-fold, but the activation energy was decreased to between −5,787 J/mol and −6,526 J/mol, and thereby the Precipitation rate was improved. Furthermore, the size of the precipitate was reduced by 5.1- to 5.5-fold, while the diffusion coefficient was increased by 6.4- to 6.9-fold.
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cavitation bubble and gas bubble induced Fractional Precipitation of paclitaxel from taxus chinensis
Process Biochemistry, 2020Co-Authors: Hoejong Kang, Jin-hyun KimAbstract:Abstract In this study, a Fractional Precipitation technique of paclitaxel using ultrasonic cavitation bubbles and gas bubbles is presented. Precipitation efficiency has been dramatically improved, and the time required for Precipitation has been reduced by 20–30 times compared to conventional methods. As a result of investigating the mechanism of Fractional Precipitation in which cavitation and gas bubbles were introduced, it was found that the bubble surface itself acts as a nucleation site, resulting in faster nucleation and thereby improving Precipitation efficiency. In addition, compared to the conventional Fractional Precipitation, the particle size was reduced by 7.8–8.9 times and 4.7–4.9 times for cavitation bubbles and gas bubbles, respectively, and the diffusion coefficient was increased by 10.3–11.9 times (cavitation bubble) and 4.7–4.9 times (gas bubble).
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ultrasound assisted Fractional Precipitation of paclitaxel from taxus chinensis cell cultures
Process Biochemistry, 2019Co-Authors: Hyewon Seo, Jin-hyun KimAbstract:Abstract In this study, we developed an ultrasound-assisted Fractional Precipitation for the purification of poorly water-soluble anticancer agent paclitaxel. The effects of ultrasound power (80, 180, 250, and 380 W) were investigated in samples of different purity (20.4, 63.6, and 92.7%) for Precipitation. Higher Precipitation rate and shorter Precipitation time were found with ultrasound treated solutions than with those without ultrasound. When the experimental data were applied to the Johnson-Mehl-Avrami-Komolgorov (JMAK) equation, the rate constant increased to 200–500-fold for 20.4% of sample purity, 150–250-fold for 63.6% of sample purity, and 60–120-fold for 92.7% of sample purity by treatment with ultrasound. In addition, the lower the purity of the sample, the greater was the decrease in activation energy compared with the control, which means that the lower the sample purity, the more effective the Fractional Precipitation using ultrasound.
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a kinetic and thermodynamic study of Fractional Precipitation of paclitaxel from taxus chinensis
Process Biochemistry, 2017Co-Authors: Chunggi Lee, Jin-hyun KimAbstract:Abstract This study investigated the effect of Precipitation time and temperature on the efficiency of Fractional Precipitation during the purification of paclitaxel. The kinetics and thermodynamics of this process were also analyzed. Fractional Precipitation was carried out at different temperatures (−10, 4, 7, 8, 10 °C) and the highest yield was obtained in the shortest time at 4 °C. The Johnson-Mehl-Avrami-Komolgorov (JMAK) equation was applied to the experimental data and nucleation and growth were found to take place simultaneously at Precipitation temperatures of −10, 4, 7, and 8 °C, while these processes occurred in a consecutive manner at 10 °C. In addition, the transformation rate (rate constant k = 1.810 × 10 −5 min −1 ) was the highest at 4 °C, suggesting that this temperature is ideal for Fractional Precipitation. Analysis of thermodynamic parameters also confirmed that Fractional Precipitation was exothermic, irreversible, and spontaneous at 4 °C.
Jiyeon Lee - One of the best experts on this subject based on the ideXlab platform.
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influence of crude extract purity and pure paclitaxel content on Fractional Precipitation for purification of paclitaxel
Separation and Purification Technology, 2013Co-Authors: Jiyeon Lee, Jin-hyun KimAbstract:Abstract Fractional Precipitation is a simple method for pre-purifying paclitaxel extracted from plant cell cultures. However, the Fractional Precipitation process has been inherently problematic due to the lengthy Precipitation time (∼3 days) that is required. In this study, we evaluated the effect of crude extract purity and pure paclitaxel content on the behavior (purity, yield, Fractional Precipitation time, precipitate shape and size) of Fractional Precipitation to improve paclitaxel purification efficiency. As the crude extract purity and pure paclitaxel content were increased, the yield and purity of paclitaxel were increased and the Precipitation time and precipitate size were decreased. Furthermore, we found that the maximum amount of pure paclitaxel content for Fractional Precipitation was 0.45–0.51% (w/v) regardless of the purity of crude extract.
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decrease in the particle size of paclitaxel by increased surface area Fractional Precipitation
Korean Journal of Microbiology and Biotechnology, 2012Co-Authors: Jiyeon Lee, Jin-hyun KimAbstract: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 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.
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Evaluation of the effect of crude extract purity and pure paclitaxel content on the increased surface area Fractional Precipitation process for the purification of paclitaxel
Process Biochemistry, 2012Co-Authors: Jiyeon Lee, Jin-hyun KimAbstract:Abstract This study evaluated the effect of crude extract purity and pure paclitaxel content on the behavior in terms of purity, yield, Fractional Precipitation time, and precipitate shape and size of Fractional Precipitation in the increased surface area Fractional Precipitation process for the purification of paclitaxel. With increased pure paclitaxel content and crude extract purity, the purity and yield of paclitaxel were improved and the Fractional Precipitation time was reduced. Regardless of changes in crude extract purity and pure paclitaxel content, it was possible to obtain a small paclitaxel precipitate size by hindering the growth of precipitate particles using an ion exchange resin to increase the surface area. In addition, according to the type of surface-area increasing substance used, precipitate size and shape differed because of a differing affinity for the paclitaxel particles. The lower the crude extract purity and pure paclitaxel content, the higher the yield and the improvement in purity in the process of increased surface area Fractional Precipitation, with a greater effect on the decrease in paclitaxel particle size.
Shingchung Lam - One of the best experts on this subject based on the ideXlab platform.
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optimization of the Fractional Precipitation of paclitaxel from a taxus chinensis cell culture using response surface methodology and its isolation by consecutive high speed countercurrent chromatography
Journal of Separation Science, 2014Co-Authors: Zhikun Liang, Zhisheng Xie, Shingchung LamAbstract:A consecutive preparation method for the isolation and purification of paclitaxel from the Taxus Chinensis cell culture was developed in this study. The process involved alkaline Al2O3 chromatography, Fractional Precipitation, and high-speed countercurrent chromatography. The original cell culture materials were first extracted with methanol using ultrasound-assisted extraction, and then the extract (the content of paclitaxel is 1.5%) was separated by alkaline Al2O3 column chromatography. Subsequently, Fractional Precipitation was used to obtain paclitaxel. In particular, response surface methodology was used to optimize the factors of Fractional Precipitation (methanol concentration, material-to-solvent ratio, and precipitating time were optimized as 48.14%, 8.85 mg/mL, and 48.71 h, respectively) and the yield of Fractional Precipitation product was 30.64 ± 0.60 mg (the content of paclitaxel is 89.3%, 27.37 ± 0.54 mg) from a 100 mg fraction by Al2O3 column separation (the content of paclitaxel is 32.4%). Then, the product was used for further isolation by high-speed countercurrent chromatography. About 1.00 g paclitaxel (200 ± 2 mg in each loading) with a purity up to 99.61% was isolated from 1.25 g of Fractional Precipitation product with a solvent system of n-hexane/ethyl acetate/methanol/water (1.2:1.8:1.5:1.5, v/v/v/v) in one run of five consecutive sample loadings without exchanging a new solvent system.
Yan Zhang - One of the best experts on this subject based on the ideXlab platform.
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stability and coagulation behavior of solid al13 purified with an ethanol acetone Fractional Precipitation method
Chemical Engineering Journal, 2012Co-Authors: Huazhang Zhao, Yan Zhang, Hongyu WangAbstract:Abstract The Al tridecamer (Al13) is the most active species in Al-based coagulant. Solid Al13 samples with high purity can be separated and purified using an ethanol–acetone Fractional Precipitation method. In this paper, we present the characterization of the stability of solid Al13 under different storage conditions as well as the performance and behavior during the coagulation process. The results show that solid Al13 has good solubility and stability, and the original distribution of the Al species and the Al13 content can be maintained stably during the dissolution, dilution and storage processes. During the studied storage period, either as liquids or solids, the Al13 neither degrades nor polymerizes. The Al13 is prone to aggregation at high concentrations, but the aggregates dissociate rapidly upon dilution. Compared with other Al species, the Al13 has better charge-neutralizing ability and can destabilize particles suspended in water more rapidly. The Al13 can decrease the optimum dosage, improving the coagulation performance at lower dosages. The coagulation mechanism of Al13 depends on its dosage and the coagulation pH, and is dominated by the charge-neutralization and enmeshing–sweeping mechanisms.
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the formation mechanism of al13 and its purification with an ethanol acetone Fractional Precipitation method
Separation and Purification Technology, 2011Co-Authors: Huazhang Zhao, Hongyu Wang, Seok Dockko, Yan ZhangAbstract:Abstract The formation mechanism of Al13 is discussed via the investigation of the distribution and transformation of Al13 in the precipitate and in the solution during the preparation of polyaluminum chloride (PACl). After the NaOH is injected into the AlCl3 solution, the monomeric Ala species reacts with OH− immediately to form the high-molecular-weight Alc species, which may exist either in the solution or in the precipitate, depending on the system temperature and the rate of base injection. Subsequently, the Alc species reacts with Ala to generate the medium-molecular-weight Alb species, i.e., Al13. The Al13 species can be separated and purified from PACl solutions with an ethanol–acetone Fractional Precipitation method. The results from ferron assay and liquid- and solid-state 27Al NMR show that the purity and the extraction yield of the extracted Al13 depend on the initial Al13 concentration. A higher Al13 content in the initial PACl solution leads to higher Al13 purity and to a higher extraction yield. A maximum purity of 99.5% for Al13 can be achieved by the described ethanol–acetone Precipitation method.
Keumyoung Jeon - One of the best experts on this subject based on the ideXlab platform.
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development of a micelle Fractional Precipitation hybrid process for the pre purification of paclitaxel from plant cell cultures
Process Biochemistry, 2010Co-Authors: Mingyeong Han, Keumyoung Jeon, Sungyong Mun, Jin-hyun KimAbstract:Abstract A micelle-Fractional Precipitation hybrid process was developed for the effective pre-purification of the anticancer agent paclitaxel extracted from plant cell cultures. First, it was found that the efficiency of such a developed process could be remarkably enhanced by removing waxy substances originating from plant cells using the adsorbent sylopute. Paclitaxel yield was improved and the Fractional Precipitation time was shortened by increasing the surface area per working volume ( S / V ) of the reacting solution through the addition of a cation exchange resin (Amberlite IR120 or Amberlite 200), an anion exchange resin (Amberlite IRA400 or Amberlite IRA96), or glass beads. Most of the paclitaxel (>98%) could be obtained after about 12 h of Fractional Precipitation using Amberlite 200. Purity increased with increasing Fractional Precipitation time up to 9 h to about 85%, after which it showed little change. On the other hand, no paclitaxel precipitate was formed using either of the nonionic exchange resins because paclitaxel, which is hydrophobic, was strongly adsorbed on the hydrophobic resin surface. Since high-purity paclitaxel can be obtained in high yield and the Precipitation time can be reduced by combining micelle formation with Fractional Precipitation, this hybrid method is expected to significantly enhance the final purification process.
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improvement of Fractional Precipitation process for pre purification of paclitaxel
Process Biochemistry, 2009Co-Authors: Keumyoung Jeon, Jin-hyun KimAbstract:Abstract Fractional Precipitation is a simple, efficient method for pre-purifying paclitaxel extracted from plant cell cultures. However, the Fractional Precipitation process has been inherently problematic due to the lengthy Precipitation time (∼3 days) that is required. An improved Fractional Precipitation process could significantly reduce the Precipitation time by increasing the purity of crude extract and the surface area available for Precipitation. Glass beads (7 mm) were used to increase the surface area, and the optimal surface area per working volume (i.e. volume of reaction solution) ( S / V ) for achieving the highest purity and yield of paclitaxel possible was found to be 0.428 mm −1 . The content of paclitaxel dissolved in methanol that can be processed during Fractional Precipitation was evaluated, and it was established that up to 0.9% (w/v) pure paclitaxel content could be processed. This improved pre-purification process serves to minimize solvent usage and the size and complexity of the high performance liquid chromatography operation required for paclitaxel purification.
