D-氨基酰化酶拆分D,L-苯丙氨酸制备D-苯丙氨酸

进行了以D,L-苯丙氨酸为原料经D-氨基酰化酶制备D-苯丙氨酸的研究。乙酰-D,L-苯丙氨酸浓度为0.5mol.L-1,给酶量为3×104U.L-1时,24 h拆分率可达到97%。采用阳离子交换树脂进行了拆分液中的D-苯丙氨酸的分离,D-苯丙氨酸的收率为95.4%。采用醋酸酐作为催化剂,在145℃的条件下,乙酰-L-苯丙氨酸可以消旋成乙酰-D,L-苯丙氨酸继续拆分。     

用吸附柱和离交柱层析法从猪血粉水解液中连续分离七种氨基酸

<正> 本文介绍了采用国产活性炭及阳离子交换树脂两种柱体巧妙地组合,并应用不同类型的洗脱剂,变换其浓度和洗脱速度,相互配合,能成功地从猪血粉水解液中一次连续分离和制取L-苯丙氨酸、L-酪氨酸、L-亮氨酸、L-缬氨酸、L-组氨酸、L-赖氨酸和L-精氨酸。多次提取试验表明,工艺操作简单、稳定可靠,苯丙氨酸与酪氨酸、亮氨酸与缬氨酸分离良好,     

发酵液中L-色氨酸分离纯化工艺研究

通过静态吸附实验,考察了温度、pH值对001×7阳离子交换树脂平衡吸附量的影响,并测定了吸附动力学曲线。通过动态实验,测定了动态吸附曲线和洗脱曲线。最后确定了001×7阳离子交换树脂分离纯化L-色氨酸的最佳工艺条件:用001×7阳离子交换树脂吸附L-色氨酸,以浓度为2 mol.L-1氨水进行洗脱,收集的流份经D315阴离子交换树脂脱色,浓缩结晶后得L-色氨酸成品,总提取率为73.0%。     

从发酵液中高效提取L-缬氨酸的工艺研究

目的:利用有机膜过滤和离子交换法分离提取发酵液中的L-缬氨酸。方法:通过有机膜过滤,除去发酵液中的菌体及蛋白,滤液浓缩结晶获得L-缬氨酸产品,通过离子交换法从结晶母液中回收部分L-缬氨酸。结果:确定了有机微滤膜和超滤膜去除发酵液中菌体蛋白和色素的操作条件;确定了采用离子交换法提取L-缬氨酸的操作条件:选择732强酸性阳离子树脂,料液pH值为3.0左右,用0.4 mol/L的氨水以1.0 mL/min的速度洗脱,L-缬氨酸的收率为89.2%。结论:通过有机膜过滤和离子交换法分离提取发酵液中的L-缬氨酸,可以提高提取收率和产品质量。     

利用酵母菌细胞转化肉桂酸生成L—苯丙氨酸

对利用酵母菌转化肉桂酸生成L-苯丙氨酸的方法进行了菌株筛选、菌体细胞培养、转化反应条件以及产物提取等方面的探索。从13个属的71株酵母菌中选到转化生成L-苯丙氨酸较高的粘红酵母(Rhodosorula glusinis)As 2.102菌株。经实验得出该菌株的最佳培养条件为:在含有1.5%酵母膏、1%葡萄糖、1.5%蛋白胨、0.05%L-苯丙氨酸、0.05% KH_2PO_4、0.5%NaCl、pH5.0的培养基中,30℃振荡培养20小时;最佳转化条件为1.5%肉桂酸、8mol/L氨、0.1?sO_4 pH10.0 30℃振荡转化反应24小时。每升转化液可生成10.78克L-苯丙氨酸,肉桂酸重量转化率为71.8%。产物用阳离子交换树脂法进行提取,所得结晶经纸层析单斑试验、生物测定、熔点、旋光、元素分析、红外光谱等项鉴定结果证实是L-苯丙氨酸,纯度超过99%。     

用D61大孔树脂从结晶母液中回收谷氨酸的研究

采用D61大孔氨型树脂,从等电点结晶母液中回收谷氨酸,上柱正交换,测出不同流率下的穿透曲线,得到交换区高度与交换速率的关系方程.同时采用3种试剂NH4Cl、(NH4)2SO4、NH3*H2O进行洗脱,其中NH3*H2O的洗脱效果较好,并测定了洗脱剂浓度和洗脱流率对洗脱效果的影响.     

离子交换树脂纯化还原型谷胱甘肽(GSH)的研究

研究005×7阳离子交换树脂分离纯化谷胱甘肽(GSH)的工艺条件。考察了005×7阳离子交换树脂对GSH的静态吸附量,洗脱时铵离子浓度、洗脱流速等对分离纯化产品GSH的影响。根据试验结果确定最佳工艺条件为:最适上柱pH为3.0,洗脱流速为:2.4ml/min,洗脱液为0.5mol/L的NH4Cl溶液;收集洗脱液,浓缩,乙醇沉淀,真空冷冻干燥,用高效液相色谱检测产品GSH,所得GSH纯度为60.8%,GSH的平均收得率为61.3%。说明此分离纯化GSH工艺可行。     

L-赖氨酸离子交换树脂的筛选

本文介绍一种从 L-赖氨酸发酵液中提取 L-赖氨酸的离子交换树脂——SR—1—3树脂。它对 L—赖氨酸的交换容量比国内普遍使用的732树脂提高25%左右。洗脱高峰集中,强度大,可望代替732树脂应用于 L-赖氨酸生产。     

活性炭-离子交换树脂联合柱层析分离猪血粉水解液中L-苯丙氨酸等多种氨基酸的新工艺

<正> 本文报道了活性炭——离子交换树脂联合柱层析分离猪血粉水解液中L-苯丙氨酸等多种氨基酸的新工艺。本工艺将猪血粉水解液通过活性炭柱吸附,依次用IN氨水,适当浓度乙醇解吸得到L-苯丙氨酸,L-酪氨酸;活性炭柱流出液再通过离子交换柱交换吸附,依次用0.05、0.1、2N氨水解吸得到L-组氨酸、L-亮氨酸、L-精氨酸、L-赖氨酸。上述六种氨基酸对猪血粉的百分收率分别为2.5、0.8、5.4、4.1、3.4、2.9。     

离子交换法在L-精氨酸发酵生产提取工艺中的应用研究

在发酵生产L-精氢酸的提取工艺中,对提取总收率影响较大的离子交换工艺进行了研究。结果表明,用国产强酸性001×7树脂对发酵液中的L-精氨酸进行动态交换吸附,当上柱流速控制在1/50vvm条件下,其交换量为1.135meq/ml湿树脂。用2.5mol/L氨水洗脱,流速控制在1/50vvm时,其洗脱效果最好。用国产201×4树脂进行脱色,每10ml树脂可脱色160ml以上的洗脱液,透光度大于90%,几乎不发生交换吸附L-精氨酸的现象。离子交换工序收率大于95%。     

Preparation of high purity biphenyl cyclooctene lignans from Schisandra extract by ion exchange resin catalytic transformation combined with macroporous resin separation

In this study, ester-bond biphenyl cyclooctene lignans were efficiently hydrolytically degraded into free biphenyl cyclooctene lignans by ion exchange resin transformation and simultaneous removal of impurities by macroporous resin. The OH-type strongly basic anion exchange resin 201×7 was the best one, and the dynamic hydrolysis efficiency was 146.7±5.0%. HPD5000 macroporous resin, which offered higher adsorption and desorption capacities and faster adsorption than other resins. The purity of free biphenyl cyclooctene lignans in the product increased from 5.14±0.24% to 79.67±0.0.67%. After dynamic catalytic transformation by 201×7 resin combined with purification of HPD5000 resin, the yield and the purity of free biphenyl cyclooctene lignans in the product were 132.1±4.7% and 80.91±3.53%, respectively.     

Evaluation of a high surface area fractional precipitation process for the purification of paclitaxel from Taxus chinensis

In this study, we evaluated a high surface area fractional precipitation process to achieve the effective purification of paclitaxel, an anticancer agent, from plant cell cultures. Fractional precipitation experiments were performed by increasing the surface area per working volume (S/V) to 0.428/mm using a variety of ion exchange resins. When the cation exchange resin Amberlite IR 120 H was used, the highest purity (>85%) and yield (>80%) of paclitaxel could be obtained in the shortest fractional precipitation time (within 6 h). Use of an ion exchange resin resulted in the production of smaller paclitaxel precipitates since it inhibited the growth of particles. When Amberlite IR 120 H in particular was used, paclitaxel particles were 2 ?? 3 times smaller (less than 30 ??m radius) than those obtained in the absence of ion exchange resin. Paclitaxel particle size was inversely correlated with the zeta potential of the fractional precipitation solution after the addition of ion exchange resin.     

从火棘果中提取精氨酸的研究

以天然野生植物火棘果为原料分离提取精氨酸,考察了树脂类型、吸附方式、温度、pH值、洗脱液、脱色及精制方法等因素对提取精氨酸的影响,并对产物进行了分析鉴定。结果表明,在20℃、pH值7-8的条件下,选用D001型大孔阳离子交换树脂静态吸附,40 min即达到饱和;以3 mol.L-1氨水为洗脱液,流速控制在40 mL.h-1,精氨酸的洗脱率达到90%以上;采用711型阴离子树脂进行脱色,D001型大孔阳离子交换树脂动态精制,精氨酸的提取率达到95.83%。     

Manufacture of cellulose nanocrystals by cation exchange resin-catalyzed hydrolysis of cellulose

Cellulose nanocrystals (CNC) were prepared from microcrystalline cellulose (MCC) by hydrolysis with cation exchange resin (NKC-9) or 64% sulfuric acid. The cation exchange resin hydrolysis parameters were optimized by using the Box–Behnken design and response surface methodology. An optimum yield (50.04%) was achieved at a ratio of resin to MCC (w/w) of 10, a temperature of 48 °C and a reaction time of 189 min. Electron microscopy (EM) showed that the diameter of CNCs was about 10–40 nm, and the length was 100–400 nm. Regular short rod-like CNCs were obtained by sulfuric acid hydrolysis, while long and thin crystals of cellulose were obtained with the cation exchange resin. X-ray diffraction (XRD) showed that, compared with MCC, the crystallinity of H₂SO₄-CNC and resin-CNC increased from 72.25% to 77.29% and 84.26%, respectively. The research shows that cation exchange resin-catalyzed hydrolysis of cellulose could be an excellent method for manufacturing of CNC in an environmental-friendly way.     

Toward the Synthesis of Pyroglutamate Lauroyl Ester: Biocatalysis Versus Chemical Catalysis

The synthesis of dodecyl pyroglutamate (or pyroglutamate lauroyl ester) was achieved in a two-step process involving a pyroglutamic acid alkyl ester intermediate. The reaction was carried out either by lipase or by chemical catalysis using ion exchange resin. Among the various tested lipases, the one from Candida antarctica B gave the best results allowing 73% formation of the desired ester after 6 h. Comparing the efficiency of this latter lipase with the one of Amberlyst IR120H resin in catalyzing this reaction, the biocatalyst gave a molar yield of pyroglutamate lauroyl ester of 79% compared to 69% when using the ion exchange resin starting with 1.04 mmol substrate in each case.     

猪脑组织总神经节苷脂提取纯化工艺的研究

本文较详细地研究论述了神经节苷脂（Ｇｌｓ）的提取纯化工艺。从猪脑组织中用萃取法获得Ｇｌｓ后,用多孔型弱碱性离子交换树脂３３５和强碱性离子交换树脂７１７对其进行分离纯化,并对工艺过程及产品品质进行了分析和比较研究,实验证明：３３５离子交换层析分离Ｇｌｓ,得率６５．９ｍｇ／１００ｇ湿组织,纯度８０．３％;７１７离子交换层析分离Ｇｌｓ,得率７７．４ｍｇ／１００ｇ湿组织,纯度７６．９％;从工艺过程及产品品质而言,采用多孔型弱碱性离子交换树脂分离提取Ｇｌｓ,具有一定的经济价值。     

Purification of bovine hemoglobin via fast performance liquid chromatography

Bovine hemoglobin (bHb) was purified from bovine red blood cells (bRBCs) via anion exchange chromatography preceded by dialysis. This is a fast and effective way to obtain bHb from bRBCs using Q Sepharose XL, a strong anion exchange resin. This resin had double the binding capacity for bHb compared to three other anion exchange resins that were studied in this work. Methemoglobin levels remained below 2% with bHb concentrations between 0.7 and 1.7 mM. The high purity of bHb was confirmed via SDS-PAGE and size exclusion chromatography (SEC).     

A method for the determination of glucose synthesis in isolated bovine hepatocytes

A simple method for determining glucose synthesis from radiolabeled precursors in isolated bovine hepatocytes using ion exchange resins is presented. This method allows processing of multiple small volume samples using suspensions of anion and cation exchange resins rather than traditional stacked column separation methods. Hepatocytes were isolated from calf liver by collagenase perfusion of the caudate lobe and were incubated with (14)C-labeled lactate or propionate as gluconeogenic substrates. Glucose synthesis was determined in an aliquot of cell suspension that was vortexed with a slurry of anion exchange (acetate form) resin, followed by a slurry of cation exchange resin. Newly synthesized, labeled glucose was recovered in the supernatant after centrifugation and quantitated by scintillation counting. Using this procedure, more than 98% of the unused labeled precursor was bound to the ion exchange resin and essentially 100% of a labeled glucose tracer was recovered in the supernatant. Pretreatment of hepatocyte suspensions with glucose oxidase was shown to eliminate the accumulation of radioactivity in the supernatant, thus confirming the specificity of this technique for measurement of newly synthesized glucose. This method was sensitive to changes in the rate of hepatic gluconeogenesis that resulted from changes in substrate concentration or the addition of glucagon or fatty acids to the hepatocyte incubations.     

Fluidized bed ion exchange for improving purification of lactic acid from fermentation

A strong anionic exchange resin was used to recover lactic acid directly from fermentation in an upflow fluidized bed column, resulting in 0.18 g lactic acid/g resin bound with a subsequent elution of 94%. When the culture broth was heated and adjusted pH to 8.0, 0.4 g lactic acid was bound per g resin, with a subsequent elution of 90%. L(+) and D(–) lactic acid isomers distribution was analyzed in the elution product resulting in an increase of L(+) isomer concentration. The resin did not alter its binding capacity after 23 cycles.