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葛根素在乙醇/硫酸铵两水相体系中的分配特性 被引量:12
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作者 王志辉 朱建航 +3 位作者 郑楠 刘国金 甄晨 戴玲 《时珍国医国药》 CAS CSCD 北大核心 2008年第1期13-15,共3页
目的研究葛根素在乙醇/硫酸铵两水相体系中的分配特性及其影响因素。方法变化体系中乙醇的浓度、添加不同分子量及浓度的PEG、改变体系pH值。结果葛根素的分配系数与回收率和体系中乙醇的浓度成正比,小分子量的PEG更有利于葛根素在上相... 目的研究葛根素在乙醇/硫酸铵两水相体系中的分配特性及其影响因素。方法变化体系中乙醇的浓度、添加不同分子量及浓度的PEG、改变体系pH值。结果葛根素的分配系数与回收率和体系中乙醇的浓度成正比,小分子量的PEG更有利于葛根素在上相的分配,增加pH值,对提高葛根素的分配系数有正面影响。结论最佳分配体系是向组成为乙醇(21%)/硫酸铵(20%)的体系中添加5%(W/W)的PEG400,最佳萃取环境为pH=7.8。 展开更多
关键词 葛根素 两水相体系 分配系数
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两水相体系中聚乙二醇浓度的测定 被引量:4
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作者 曹学君 刘彦明 邬行彦 《分析化学》 SCIE EI CAS CSCD 北大核心 1993年第12期1470-1470,共1页
1 引言 利用两水相体系作为生物反应器进行生物转化反应,或者提取生物大分子,近年来受到国内外关注。聚乙二醇(PEG)-葡聚糖(Dextran)是最常用的两水相体系,在实际应用中,了解上下两相的组成是十分必要的,因此,建立合适的测定两水相体系... 1 引言 利用两水相体系作为生物反应器进行生物转化反应,或者提取生物大分子,近年来受到国内外关注。聚乙二醇(PEG)-葡聚糖(Dextran)是最常用的两水相体系,在实际应用中,了解上下两相的组成是十分必要的,因此,建立合适的测定两水相体系的方法是研究和应用两水相体系的基础工作。 展开更多
关键词 聚乙二醇 两水相体系 浓度
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PEG修饰青霉素酰化酶及其在两水相生物转化体系中的分配
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作者 何汉平 刘叶青 +1 位作者 曹学君 张秀萍 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第1期109-112,共4页
采用对甲苯磺酰氯法 ,用聚乙二醇对青霉素酰化酶进行化学修饰 ,修饰酶的比活为未修饰酶的 75% ,稳定性比游离酶有了很大提高。酶在带修饰酶的聚乙二醇与葡聚糖组成的两水相体系中的分配系数为 2 5。
关键词 对甲苯磺酰氯 修饰酶 两水相体系 聚乙二醇 青霉素酰化酶 化学修饰 分配系数
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Surfactant-coated Candida rugosa Lipase as Catalyst for Hydrolysis of Olive Oil in Solvent-Free Two-Phase System
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作者 宋宝东 丁辉 +3 位作者 吴金川 Hayashi Y. Talukder MMR 王世昌 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第5期601-603,共3页
The surfactant-coated Candida rugosa lipase was used as catalyst for hydrolysis of olive oil in two-phase system consisting of olive oil and phosphate buffer without organic solvent. For both the coated and native lip... The surfactant-coated Candida rugosa lipase was used as catalyst for hydrolysis of olive oil in two-phase system consisting of olive oil and phosphate buffer without organic solvent. For both the coated and native lipases,the optimal buffer/oil volume ratio of 1.0, aqueous pH 6.8 and reaction temperature 30℃ were determined. The maximum activity of the coated lipase was ca 1.3 times than that of the native lipase. The half-life of the coated lipase in olive oil and the native lipase in phosphate buffer was ca 9 h and 12 h, and the final residual activity was 27% and 20% of their initial values, respectively. The final substrate conversion by the coated lipase was ca 20% higher than that of the native lipase. 展开更多
关键词 Candida rugosa HYDROLYSIS LIPASE olive oil solvent-free system SURFACTANT
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Correlation of Critical Loci for Water-Hydrocarbon Binary Systems by EOS Based on the Multi-Fluid Nonrandom Lattice Theory
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作者 Hun Yong SHIN Hwayong KIMb +3 位作者 Ki-Pung YOO Chul-Soo LEEd Yoshio IWAI Yasuhiko ARAI 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第6期661-665,共5页
Quantitative representation of complicated behavior of fluid mixtures in the critical region by any of equation-of-state theories re-mains as a difficult thermodynamic topics to date. In the present work, a computatio... Quantitative representation of complicated behavior of fluid mixtures in the critical region by any of equation-of-state theories re-mains as a difficult thermodynamic topics to date. In the present work, a computational efforts were made for representing various types of critical loci of binary water with hydrocarbon systems showing Type II and Type III phase behavior by an elementary equation of state [called multi-fluid nonrandom lattice fluid EOS (MF-NLF EOS)] based on the lattice statistical mechanical theory. The model EOS requires two mo-lecular parameters which representing molecular size and interaction energy for a pure component and single adjustable interaction energy pa-rameter for binary mixtures. Critical temperature and pressure data were used to obtain molecular size parameter and vapor pressure data were used to obtain interaction energy parameter. The MF-NLF EOS model adapted in the present study correlated quantitatively well the critical loci of various binary water with hydrocarbon systems. 展开更多
关键词 critical locus WATER HYDROCARBON lattice theory multi-fluid theory*
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