聚乙二醇/硫酸铵双水相体系萃取猪胰蛋白酶

采用聚乙二醇(PEG)/硫酸铵[(NH4)2SO4]双水相体系对猪胰蛋白酶分离进行了研究。通过综合考察酶分配系数、蛋白质分配系数、相比和回收率,探讨了PEG400质量分数、(NH4)2SO4质量分数、NaCl质量分数以及pH值对胰蛋白酶萃取的影响,并通过正交实验进一步优化实验条件,结果表明(NH4)2SO4质量分数和PEG浓度对胰蛋白酶的萃取影响大,在PEG400质量分数为24%、(NH4)2SO4质量分数为21%、pH值为4.2所组成的双水相体系下,可获得酶的高分配系数8.48,提取的胰蛋白酶活力达到1780 U/mL。     

聚乙二醇一硫酸铵双水相萃取结晶紫的研究

利用分光光度法研究了结晶紫在聚乙二醇一硫酸铵双水相体系中的萃取行为,探讨了质量配比( mPEG/m(NH4)2SO4)、温度、结晶紫浓度对结晶紫的分配系数(cup/Clow)及萃取率的影响.结果表明,在一定的温度和结晶紫浓度下,随着质量配比的减小,结晶紫的分配系数增大,萃取率略有降低;在一定的质量配比和结晶紫浓度下,随...     

聚乙二醇-硫酸铵双水相萃取结晶紫的研究

利用分光光度法研究了结晶紫在聚乙二醇-硫酸铵双水相体系中的萃取行为,探讨了质量配比(mPEG/m(NH4)2SO4)、温度、结晶紫浓度对结晶紫的分配系数(cup/clow)及萃取率的影响。结果表明,在一定的温度和结晶紫浓度下,随着质量配比的减小,结晶紫的分配系数增大,萃取率略有降低;在一定的质量配比和结晶紫浓度下,随着温度的升高,分配系数显著增大,萃取率基本保持不变;在一定的质量配比和温度下,随着结晶紫浓度的增大,分配系数显著减小,萃取率基本保持不变;在mPEG/m(NH4)2SO4为1.25∶1、结晶紫浓度为6.536×10-5 mol.L-1、温度为50℃的条件下,萃取率高达99.81%。     

丙醇/硫酸铵双水相体系分离纯化茶皂素的研究

以茶饼中提取的茶皂素为粗品原料（茶皂素质量分数为40.2%）,采用丙醇/硫酸铵双水相体系对粗品茶皂素进行分离提纯。考察了硫酸铵质量分数、丙醇质量分数、萃取温度、萃取pH对茶皂素产品萃取率和产品含量的影响。结果表明：该工艺分离速度快,产品萃取率和含量较高,在硫酸铵质量分数为20%、丙醇质量分数为23%、温度为40 ℃、pH为7时,茶皂素萃取率可达到89.32%,茶皂素质量分数可达到78.12%。     

丙醇/硫酸铵双水相体系分离纯化茶皂素

以茶饼中提取的茶皂素为粗品原料(茶皂素质量分数为40.2%),采用丙醇/硫酸铵双水相体系对粗品茶皂素进行分离提纯。考察了硫酸铵质量分数、丙醇质量分数、萃取温度、萃取p H对茶皂素产品萃取率和产品含量的影响。结果表明,该工艺分离速度快,产品萃取率和含量较高,在硫酸铵质量分数为20%、丙醇质量分数为23%、温度为40℃、p H为7时,茶皂素萃取率可达到89.32%,茶皂素质量分数可达到78.12%。     

聚乙二醇双水相体系在萃取分离中的应用

聚乙二醇双水相体系具有易分相、价格低廉、萃取高效温和、无毒、对萃取物活性损失小等优点。本文综述了近几年来聚乙二醇双水相体系及其在蛋白质、生物酶、生物活性物质、抗生素、金属离子等萃取分离方面的应用进展,展望了聚乙二醇双水相在分离方面的应用前景和发展方向。     

乙醇/硫酸铵双水相体系萃取甘草酸钾的研究

实验考察了乙醇/硫酸铵双水相萃取甘草酸钾的可能性及其影响因素,结果表明,甘草酸钾在该体系的分配系数K和收率均随乙醇、硫酸铵质量分数的增加而增大,而随着pH的增加先增加后减小。且在w(乙醇)=35 1%,w(硫酸铵)=17 7%,pH=6 0左右时,分配系数K可达13 7,收率η可达96 3%。这将为甘草酸钾的提取分离提供一种新的可能。     

蛋白质-磷酸钾-聚乙二醇双水相体系热力学研究

建立了由蛋白质、磷酸氢二钾、磷酸二氢钾、聚乙二醇所组成的双水相体系的平衡浓度分析测定方法,实验测定了6种蛋白质分子在25℃下的液液平衡分配数据,共23组.将Baskir等的吸附晶格模型和Pitzer的长程静电项相结合,扩展用于含电解质-高聚物双水相体系的热力学计算,仅用7组实验数据进行关联,得到2个吸附能参数,预测了其它16组蛋白质分配系数,结果满意。并提出了蛋白质分配系数与双水相成相物质在两相间浓度差的经验关系式。     

蒲公英总黄酮在聚乙二醇-硫酸铵双水相体系中的分配与提取

蒲公英中内含的黄酮类物质具有较高药用价值,用双水相萃取法提取植物中有效成分是新型提取高附加值生物质的有效方法。本文考察了PEG/(NH4)2SO4双水相体系萃取分离蒲公英总黄酮时聚乙二醇相对分子质量、PEG质量分数、(NH4)2SO4质量分数、温度、pH值5个因素对分配行为的影响,并通过正交实验优化了工艺条件。结果表明最佳双水相提取工艺条件为：(NH4)2SO4质量分数18%,PEG1000质量分数23%,pH值5.34,提取温度25℃,NaCl盐的存在与否对萃取影响很小,蒲公英中总黄酮的提取率可达5.47%。因此,使用双水相法提取蒲公英总黄酮是该类提取技术中一种更加绿色环保和高效的方法。     

硫酸铵—聚乙二醇双水相体系热力学研究

本文建立了由一种无机盐(硫酸铵)和一种高聚物(聚乙二醇)及水所组成的三元体系(不含生物物质)的平衡浓度分析方法,实验共测定了聚乙二醇数均分子量分别为1000,1540,2000和4000四种共43组在25℃下的液-液平衡数据(包括临界点数据)。将UNIQUAC和UNIFAC方程分别扩展,并与Fowler-Guggenheim长程静电项相结合,关联了此双水相三元液-液平衡数据,结果表明:扩展的UNIFAC方程对此三元体系具有预测推算的功能。     

溪黄草黄酮配合物的合成及抑制亚硝化反应研究

超声波最优化法提取溪黄草总黄酮,提取物经乙酸乙酯萃取后进行柱层析分离纯化,得一纯物质,鉴定为黄酮化合物,并以该化合物为配体合成了锌(Ⅱ)、铜(Ⅱ)和铁(Ⅲ)配合物,研究它们对亚硝化反应的抑制作用。结果表明该黄酮化合物及其配合物在一定浓度范围能阻断亚硝胺的合成及清除亚硝酸盐,其中配合物作用较黄酮配体强。     

溪黄草黄酮的超声波法提取与活性研究

采用超声波法提取溪黄草中的总黄酮,用正交法确定了最佳提取工艺,并与常规回流提取法作了比较研究。超声波法的最佳提取条件为:使用60%乙醇作溶剂,在温度60℃,料液比为1∶40条件下超声波辅助提取20 min,连续提取2次,黄酮的总提取率可达99.81%。研究了黄酮提取物对羟自由基的抑制作用及体外抑菌作用,结果表明,溪黄草黄酮提取物对羟自由基有抑制作用,对金黄色葡萄球菌和枯草杆菌有一定的抑菌效果。     

正交试验优选溪黄草袋泡茶的提取工艺

采用正交试验,考察加水量、提取时间、提取次数3个因素对提取工艺的影响,以总黄酮、总三萜含量及干膏得率为指标,采用紫外-可见分光光度法测定总黄酮、总三萜含量,烘干法测定干膏得率,优选溪黄草袋泡茶的提取工艺。结果表明,最佳提取工艺为药材加10倍量水,加热提取3次,每次提取1小时。该工艺设计稳定、合理、可行,可用于溪黄草袋泡茶的提取。     

Separation and Purification of Aloe Anthraquinones Using PEG/Salt Aqueous Two-Phase System

The anthraquinones were extracted from Curacao aloe leaves. Aqueous two-phase system (ATPS) of polyethylene glycol (PEG)/salt, coupled with spectrophotometry and high performance liquid chromatography (HPLC) were employed for the first time as an attractive alternative for the downstream processing of aloe anthraquinones, mainly for the removal of the impurities without additional steps. The influence factors such as molecular mass and concentration of PEG, type, and concentration of neutral salt, temperature, and pH on the phase partition behavior of ATPS had been studied. Under the optimal condition, the highest extraction yield 90.54% was obtained in PEG phase using PEG-6000/(NH₄)₂SO₄ system to a mass ratio of 2:1 at 40°C, pH 3.0 with 0.6 g sodium chloride added. The reverse extraction of anthraquinones from the PEG phase was achieved with a recovery of 70.15% by adjusting the pH. Meanwhile, the PEG could be recycled. The major components in aloe anthraquinones of aloe-emodin and chrysophanol were analyzed by HPLC before and after ATPS extraction process. Compared with conventional purification methods, this technique can be completed in one operation; besides it is low-cost and environmentally friendly.     

Potassium Phosphate Salts-Based Aqueous Two-Phase Systems Applied in the Extraction of Gallic Acid from Guava

Aqueous two-phase systems (ATPS) consisting of potassium phosphate salt + alcohol or polyethylene glycol were investigated to extract gallic acid. The partitioning process was studied using purity gallic acid (GA). The constituents either promote the partition process of GA to bottom or top phase, leading to the creation of versatile systems. The salt acts as a drive force of process because it influences the value of phase pH, and consequently the deprotonation of biomolecule and its partition. The results using GA from guava are in close agreement with the model systems, validating the experimental data and supporting their applicability in real systems.     

Partitioning of Charged Solutes in Poly(Ethylene Glycol)/Potassium Phosphate Aqueous Two-Phase Systems

Abstract

A mathematical model based on the dissociation of charged compounds and the pH of each phase is developed to describe the partitioning of charged compounds in aqueous two-phase systems. Observed partition coefficients of several charged and uncharged compounds, including three pairs of oppositely charged analogs (tryptamine/indole 3-acetic acid, 5-methoxytryptamine/5-methoxyindole 3-acetic acid and 2-(p-tolyl) ethylamine/p-tolyl acetic acid), are compared in identical poly-(ethylene glycol)/potassium phosphate aqueous two-phase systems over the pH range of 5.5 to 9.2. Among these pairs, the partition coefficients of the acids increased with increasing pH, from 8.4 to 33.3 for indole 3-acetic acid, from 11.4 to 53.9 for 5-methoxyindole 3-acetic acid, and from 4.2 to 17.7 for p-tolyl acetic acid. The amine partition coefficients also increased with increasing pH, from 4.0 to 7.8 for tryptamine, from 5.8 to 12.2 for 5-methoxytryptamine, and from 1.6 to 3.0 for 2-(p-tolyl) ethylamine, respectively. Consistent with the derived model, the greatest rate of increase in the partition coefficients of the acids occurs at low pH, while the greatest rate of increase in amine partition coefficients occurs at high pH. The ratio of partition coefficients for these pairs predicted by the model agrees with the observed partition ratio. The results indicate that charge, in addition to hydrophobic effects previously described, plays a major role in the partitioning of biological compounds.     

内折香茶菜叶挥发油的化学成分

用水蒸气蒸馏法、两相溶剂萃取法从新鲜内折香茶菜叶中提取挥发油,用气相色谱-质谱联用技术对挥发油的化学成分进行了分析,用气相色谱面积归一法测定了各个成分的相对质量分数。共分离出16个峰,鉴定出16个化学成分。内折香茶菜挥发油中的主要成分为香芹酚(相对质量分数76.45%)、石竹烯(5.65%)、1-甲基-4-(1-异丙基)-1,4-环己二烯(3.68%)和2,6-二甲基-6-(4-甲基-3-戊烯基)-双环[3.1.1]2-庚烷(2.74%)。     

水/有机溶剂两相体系中生物转化合成2-苯乙醇

研究了在水/有机溶剂两相体系中生物转化合成2-苯乙醇的工艺,选择确定了构建两相体系的有机溶刺,考察了有机溶荆加入体积、转化培养的振荡转速和温度以及底物浓度对2-苯乙醇合成影响.结果表明,油酸是构建两相体系的最佳溶剂,在油酸加人体积与培养基体积比为1:3,振荡转速250 r/min,温度30℃,底物浓度14 g/L的条件下,转化培养18 h,有机相和水相中2-苯乙醇的浓度分别为14.9 g/L和1.74 g/L,2-苯乙醇收率为65%,生产率达到0.37 g/(L·h).     

Thermoseparating Aqueous Two-Phase System for the Separation of Alkaline Proteases from Fish Viscera

The objective of this study was to isolate alkaline proteases from farmed giant catfish viscera by using a thermoseparating aqueous two-phase system (T-ATPS). Different phase partitioning parameters—type of salts, NaCl addition, and temperature—were optimized. The optimum system contained 40% EOPO3900-10% MgSO₄ with 17%NaCl, induced phase separation at 55°C, and provided the highest recovery (77.98 %) and purity (PF: 21.50-fold) with a partition coefficient (K_E) of 11.90 and a volume ratio (V_R) of 0.19. In the recycling step, the mixture of the bottom salt-rich phase and bottom EOPO-rich phase in the ratio of 0.5:1.5 (w/w) provided the highest recovery and purity. Hence, the total recovery of 91.62% was obtained from the separation system. Three major clear zones (24, 36, and 130 kDa) can be distinctively observed on casein-substrate gel electrophoresis for protease activity staining. Major protein components of perilla seed hydrolysates were completely hydrolyzed by the alkaline proteases at 70 units while those of red kidney bean isolate were more resistant to protein hydrolysis. Fifty units of Flavourzyme® hydrolyzed completely both plant proteins into small peptides or amino acids. As a result, T-ATPS could be used as an alternative method for the separation of enzymes from various sources with acceptable recovery. In addition, the obtained alkaline proteases can be further used in preparation of protein hydrolysates.