Separation of salidroside from the fermentation broth of engineered Escherichia coli using macroporous adsorbent resins

Salidroside (8-O-β-D-glucoside of tyrosol), a plant-derived natural product, is used for treatment of hypoxia, fatigue and aging diseases. The availability of salidroside is restricted since it is extracted from 3-5 years old Rhodiola roots, which grow very slowly in the cold region of northern hemisphere of Earth. Our laboratory has constructed an engineered Escherichia coli and established a fermentation process to produce salidroside from glucose. In this article, nine macroporous resins from polarity to non-polarity, including NKA-9, S-8, AB-8, SP825, D101, LSA-8, LX-12, LX-18 and LX-68 resins, were tested to separate salidroside from fermentation broth. After static and dynamic experiments, the weakly polar SP825 resin had a better separation efficiency among nine resins. The adsorption kinetic and isotherm of salidroside on the SP825 resin were determined, and the pseudo-second-order kinetic model and Langmuir model could be fitted well. The effects of the pH on adsorption and ethanol concentration on desorption were investigated, and an optimal separation process was established. The adsorption for salidroside in the SP825 resin column was conducted with loading 150 ml at pH 7, and desorpted by washing 50 ml of 80% ethanol solution. Under the best process conditions, the purity and yield of salidroside in the final product were 91.6% and 74.0%, respectively. The results showed that the macroporous SP825 resin would be feasible and effective to prepare salidroside and has promising application in the downstream process of microbial fermentation.     

吸附树脂极性的高效液相色谱法测定及表征

建立了测定及表征吸附树脂极性的高效液相色谱法。DA-201极性树脂、AB-8弱极性树脂和D-101非极性树脂分别填充高效液相色谱柱,以去离子水为流动相,葡聚糖为示踪剂,流速1.0 mL/min,柱温30℃,测定树脂的极性。结果表明,正丁醇、乙醇均可作为单一探针分子,流出顺序可定性表征吸附树脂极性:DA-201极性树脂AB-8弱极性树脂D-101非极性树脂;采用乙醇/甲醇作为探针分子组,通过相对极性法计算,得到3种吸附树脂的定量极性值:DA-201极性树脂极性值100,AB-8弱极性树脂极性值18,D-101非极性树脂极性值0,相对标准偏差(RSD)均小于1.50%。方法稳定可靠,可以有效表达吸附树脂的极性。     

大孔聚苯乙烯吸附树脂对鳕鱼排免疫活性肽的脱盐

比较了6种聚苯乙烯型大孔树脂对鳕鱼排活性肽的吸附能力,并研究了各因素(温度、pH、吸附物浓度、料液比等)对树脂吸附特性的影响. 通过动态吸附与解析实验,探讨了DA201-C树脂对鳕鱼排活性肽脱盐的可行性. 结果表明,DA201-C树脂对鳕鱼排活性肽吸附能力最强,在温度25℃、pH 4.0、溶液浓度10 mg/mL、料液比(树脂质量与活性肽体积比)2 g/mL的条件下,吸附率最高为84.7%. 在动态吸附解析实验中,多肽的脱盐率为98.1%,回收率为90.3%. 且脱盐后的多肽同样具有促进脾细胞增殖活性且呈剂量依赖关系.     

Preparative Separation of Glabridin from Glycyrrhiza glabra L. Extracts with Macroporous Resins

Abstract

In the present study, the performance and adsorption characteristics of five macroporous resins for the separation of glabridin from Glycyrrhiza glabra L. have been evaluated. The adsorption and desorption properties of glabridin on macroporous resins including HPD100, HPD300, HPD800, NKA and H103 were compared. HPD100 resin offered the best adsorption and desorption capacities based on the research results. Both Langmuir and Freundlich isotherms were used to describe the interactions between the solutes and resins at different initial concentrations. Dynamic adsorption and desorption experiments on HPD100 resin packed column were conducted to optimize the separation process of glabridin from licorice extracts. After the treatment with stepwise elution on HPD100 resin, the content of glabridin in the product increased from 0.21% to 32.2% which is 153-fold higher than it in G. glabra L. roots and the recovery yield was 79.7%. The results indicated the good ability of HPD100 resin for separation glabridin and the study may provide scientific references for the large-scale glabridin production from G. glabra L. or other plants extracts.     

大孔吸附树脂分离纯化杜仲中京尼平甙酸

比较了NKA-9、D311、S-8、HPD600、NKA-2、A型、D140、聚酰胺8种树脂对杜仲中的降血压活性成分京尼平甙酸(GPA)的吸附及脱附性能,从中筛选出吸附率(88.17%)及脱附率(97.71%)均较高的A型树脂进行实验。最佳工艺条件为:杜仲皮粉末用φ(乙醇)=50%的水溶液提取后,乙醇沉淀,上清液调节pH=6~9后,用A型树脂吸附220 m in,装柱,用φ(乙醇)=15%的水溶液洗脱,流速为1.5 mL/m in,洗脱液浓缩后,冷冻干燥得产品。京尼平甙酸的收率为84.03%,w(GPA)=84.06%。     

深共熔溶剂-水混合物同步提取红景天苷和酪醇的响应面优化及其分离回收

以深共熔溶剂-水混合物（LAEG40）作为提取溶剂，红景天苷提取率为主要指标，酪醇提取率为辅助指标，在前期单因素实验的基础上，利用响应面法考察了液料比、提取温度、提取时间三个主要因素对红景天中红景天苷和酪醇同步提取的影响。得到的最佳提取条件为: 液料比12.05:1(mL/g)，提取温度60 ℃，提取时间35 min。在此条件下LAEG40对红景天苷的提取率可达到19.3552?0.6604 mg/g，酪醇提取率可达到1.7211?0.0585 mg/g，远高于传统溶剂水、乙醇对红景天苷和酪醇的提取率。为实现LAEG40提取红景天苷和酪醇的回收，进行了大孔树脂吸附分离的研究。经过一系列优化，获得的最佳吸附分离条件为：选用SP-825树脂装柱，每10g树脂上样30 mL LAEG40提取液，洗脱剂选用80 %乙醇，洗脱体积40 mL，洗脱流速1 mL/min，在此条件下红景天苷和酪醇的回收率分别可达60.47 %和85.07 %。     

大孔吸附树脂纯化石榴皮多酚

从D3520、D4020、AB-8、D140、D141、D160、DM-301、DA-201、SAD-7和D101大孔吸附树脂中筛选出D141树脂,研究了其对石榴皮多酚的静态与动态吸附和解吸性能。结果表明,D141树脂对石榴皮多酚的饱和吸附量为19.86 mg/g(干树脂),吸附等温线符合Langmuir方程,饱和吸附时间为5 h,适宜解吸剂为体积分数70%的乙醇溶液;以质量浓度9 mg/mL的石榴皮提取液上柱,流速为1.8~2.0 BV/h时,树脂的多酚穿透吸附容量为39.42 mg/g(干树脂),2.5 BV体积分数70%的乙醇溶液可将吸附于柱上的石榴皮多酚完全洗脱。以该条件纯化石榴皮多酚提取物时,纯化样的收率为15.4 g/100 g(石榴皮),多酚质量分数从34%提高到76.34%。     

Modification of faujasites to generate novel hosts for “ship-in-a-bottle” complexes

Zeolites X, Y, and DAY have been modified by a post-synthetical dealumination procedure to generate mesopores that are completely surrounded by micropores. In these novel host materials several bulky transition metal salen complexes have been occluded via the “ship-in-a-bottle” synthesis approach. Both the host materials and the “ship-in-a-bottle” catalysts have been characterized by FTIR spectroscopy and nitrogen adsorption. Additionally, the “ship-in-a-bottle” catalysts have been characterized by thermogravimetric analysis and ICP-AES spectroscopy. The catalysts have been tested in the stereoselective epoxidation of R-(+)-limonene and (−)--pinene with molecular oxygen as oxidant. The best results so far — 100% conversion, 96% selectivity and 91% de — were achieved with the immobilized (R,R)-(N,N′)-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethylene-1,2-diaminocobalt complex in the epoxidation of (−)--pinene.     

大孔吸附树脂纯化黄花蒿黄酮及其抗氧化活性

该文对大孔吸附树脂纯化黄花蒿黄酮的工艺条件进行了研究与优化,并对纯化后的黄酮进行了抗氧化活性的研究。比较了AB-8,DM-101,DA-201,D-101及SD-401对黄花蒿中黄酮类物质的吸附及解吸附性能,结果显示,D-101的综合效果最佳。通过D-101大孔吸附树脂动态吸附解吸实验,获得较佳的纯化工艺:上样液黄酮质量浓度为1.55 g/L,流速为2 mL/min,上样100 mL后,用蒸馏水洗脱至溶液无色,再用250 mL体积分数70%乙醇以1 mL/min洗脱。在该条件下,黄酮质量分数从20.10%提高到80.32%,洗脱率达91.08%,黄酮回收率为68.25%。黄花蒿黄酮对油脂有明显的抗氧化性作用;黄花蒿黄酮对植物油的抗氧化能力强于柠檬酸和抗坏血酸,对动物油脂的抗氧化能力稍弱于抗坏血酸而略强于柠檬酸。     

大孔吸附树脂分离纯化银杏叶总黄酮的研究

利用4种大孔吸附树脂分离纯化银杏叶总黄酮.结果表明,HPD100型大孔吸附树脂最适合分离纯化银杏叶总黄酮,该树脂的静态饱和吸附量(以干树脂计)为63.8 mg·g-1,静态洗脱率为91.2%,动态饱和吸附-洗脱量为14.0 mg·g-1,洗脱剂为70%乙醇,洗脱剂用量为4倍树脂体积,树脂可重复使用7个周期.     

Phase transition phenomena of the adsorbed 1-dodecanol monolayer at the air–water interface

Phase transition phenomenon of the 1-dodecanol monolayer at the air/water interface was studied by the dynamic γ(t) curves and the adsorption isotherm obtained by ellipsometry at 20 °C. The surface-concentration adsorption isotherm clearly showed three abrupt increases at bulk concentration C of 1.3 × 10⁻⁹, 2 × 10⁻⁹ and 3.7 × 10⁻⁹ mol/mL, respectively. The 1st and the 3rd transitions observed herein, that were typical 2D first-order transitions, were consistent with the gas to liquid expanded (G–LE) and the liquid expanded to liquid condensed (LE–LC) phase transitions observed in a previous tensiometry study. The 2nd transition that occurred at C = 2 × 10⁻⁹ mol/mL was not identified from any previous dynamic surface-tension profiles. Judging from the substantial increase in the film thickness of the transition, it was believed that the orientation change of the adsorbed molecule was involved in the LE phase. A LE_h and a LE_v phase, that denoted the “lie-down” and “stand-up” types of adsorption, respectively, was used to describe this transition and a cusp, instead of a constant surface-tension region, was observed in the dynamic γ(t) curves for this transition. This suggested that, since the surface tension varied during the transition process, the newly identified LE_h and LE_v transition might not be the typical first-order type of phase transition.     

ISOTHERMAL AND NON-ISOTHERMAL MULTICOMPONENT ADSORPTION KINETICS

The model equations in the relaxation form for the multicomponent kinetics of isothermal and non-isothermal adsorption, taking into account all major distinctive features of the interphase heat and mass exchange inside porous grains and at their surface (see points 1 to 4 below) for P (“pore”) and S (“solid”) models of mass transfer within porous grains of the adsorbent, have been obtained.

First for isothermal and non-isothermal kinetics in the mixed kinetics region of mass and heat exchange in the absence natural mutual diffusion and natural thermal-diffusion the essential influence effective mutual diffusion and effective thermal-diffusion is shown.

Recommendations on the use of model equations of adsorption kinetics for describing isothermal and non-isothermal adsorption dynamics of multicomponent mixtures in the inner-diffusion and mixed (outer- and inner-diffusion) kinetic region of heat and mass exchange are made.     

Enrichment and Purification of Syringin, Eleutheroside E and Isofraxidin from Acanthopanax senticosus by Macroporous Resin

In order to screen a suitable resin for the preparative simultaneous separation and purification of syringin, eleutheroside E and isofraxidin from Acanthopanax senticosus, the adsorption and desorption properties of 17 widely used commercial macroporous resins were evaluated. According to our results, HPD100C, which adsorbs by the molecular tiers model, was the best macroporous resin, offering higher adsorption and desorption capacities and higher adsorption speed for syringin, eleutheroside E and isofraxidin than other resins. Dynamic adsorption and desorption tests were carried out to optimize the process parameters. The optimal conditions were as follows: for adsorption, processing volume: 24 BV, flow rate: 2 BV/h; for desorption, ethanol-water solution: 60:40 (v/v), eluent volume: 4 BV, flow rate: 3 BV/h. Under the above conditions, the contents of syringin, eleutheroside E and isofraxidin increased 174-fold, 20-fold and 5-fold and their recoveries were 80.93%, 93.97% and 93.79%, respectively.     

COMPREHENSIVE STUDY OF THE GAS HOLD UP AND BUBBLE SIZE DISTRIBUTION IN HIGHLY VISCOUS LIQUIDS II. CMC SOLUTIONS

Following properties of short bubble columns employing CMC solutions (1.0, 1.4 and 2.0%) and perforated plates (0.5, 1.0 and 3.0 mm hole diameters) were determined: relative mean gas hold up, E_G, bubble size distribution, Sauter bubble diameter, d_s, and the specific geometrical bubble surface areas, a' and a' due to the “intermediate to large bubbles.” The a' values were compared with the corresponding volumetric mass transfer coefficients, k_La's and the mass transfer coefficients, k_L, were estimated. The properties of these systems were investigated as function of the superficial gas velocity, W_SG, CMC concentration and aerator type.     

基于Aspen Adsorption的氦气/甲烷吸附分离过程模拟优化

工业氦气主要通过深冷、膜分离和变压吸附（PSA）耦合从天然气提取,其中PSA是获得高纯He的关键。吸附过程模拟可以克服实验局限,有效指导工程设计、优化工艺条件。以体积分数90%的粗He为原料,利用Aspen Adsorption软件建立He/CH₄ 单塔PSA模型,获得穿透曲线。以此为基础,建立双塔分离流程,分析吸附、顺放、逆放、冲洗、升压步骤中吸附塔内气相组成的变化,五步最佳操作时间分别为 60、180、30、60和180 s。在三塔流程中,一个循环周期的最佳吸附时间和均压时间分别为135 s和90 s,产品纯度可达98.42%,回收率达60.45%。在五塔流程中,考虑到各步骤时间的匹配及生产的连续性,需要对一个周期内的循环时间进行优化。循环时间为300~340 s时,产品纯度达到99.07%以上。     

阻尼剂提高硅橡胶阻尼性能的研究

采用阻尼剂提高硅橡胶阻尼性能,研究了不同阻尼剂对硅橡胶性能的影响。结果表明,阻尼剂DA—1和DA—3均可有效提高硅橡胶阻尼系数。采用阻尼剂DA—1/DA—3配比为15/5时,硅橡胶阻尼性能最优,综合性能最好。     

大孔吸附树脂纯化草木樨香豆素的动力学和热力学

通过静态吸附和解吸实验筛选出纯化草木樨香豆素的大孔吸附树脂,确定了HPD300树脂纯化香豆素的吸附动力学模型、等温吸附模型和热力学参数,并通过动态吸附和解吸实验优化其工艺条件。结果表明:HPD300树脂对香豆素的吸附量大、解吸率高、吸附速度快,其吸附动力学可用拟二级动力学方程很好地描述,等温吸附过程可用Langmu ir方程较好地拟合,其吸附是一个自发、放热的物理吸附过程,在优化的条件下产物中香豆素的纯度大于90%,回收率高于90%。研究表明:HPD300树脂是一种分离纯化草木樨香豆素的理想树脂,可用于大规模分离纯化草木樨香豆素。     

Adsorption and association of xanthine in absence and presence of some divalent metal ions at the mercury/solution interface

The adsorption and interfacial orientations of xanthine were studied by out-of-phase ac voltammetry at a hanging mercury drop electrode. The adsorption equilibrium and its attainment have been investigated as a function of various parameters such as pH, adsorption potential, temperature, adsorption time, the nature of anions of the supporting electrolyte and the bulk concentration of xanthine. The changes in the stacking interactions of xanthine molecules in the presence of Cd(II), Cu(II), Co(II), Ni(II), Ca(II) and Mg(II) were studied by ac voltammetry as changes in “pits” or “wells” on double layer capacitance curves due to adsorption and association of M(II)-xanthine complexes on the charged interface. The results indicate that the complexation of xanthine molecules enhances the stacking interactions and hence would be expected to facilitate the formation of perpendicularly stacked layer of M(II)-xanthine complex on the electrode surface. The time dependence of the electrode impedance indicates that the formation of a compact film in absence and presence of these metal ions controlled by a fixed number of nuclei and the data were analysed according to the Avrami equation. The adsorption parameters of xanthine have been computed at different pH values in the absence and the increased presence of metal ions.     

Preparation of high purity squalene from soybean oil deodorizer distillate with the combination of macroporous resin and thin-film evaporation coupling distillation

ABSTRACT

In this study, the combination of macroporous adsorbent resins (MARs) and thin-film evaporation coupling distillation (TFECD) was studied systematically, with aim to obtain high value-added squalene from soybean oil deodorizer distillate (SODD). Five types of resins (X-5, D-101, D4020, DM301, and AB-8) were first used to evaluate the adsorption/desorption properties of squalene. D101 resin exhibited higher adsorption/desorption capacities and desorption ratios for squalene based on static adsorption results among the tested resins. We further investigated the adsorption kinetics, isotherms, and thermodynamics with D101 resin as adsorbent. The adsorption of squalene on D101 was best fitted to pseudo-second-order kinetic model and the Langmuir equation. The dynamic adsorption and desorption indicated that similar results were observed in the static adsorption test. The purity of squalene was increased from 7.5 to 82.5% with the recovery up to 88.5% after separation on D101 column. The resin-refined sample was directly subjected to TFECD purification. Under optimized process parameters, the final product with purity of 98.5% and recovery yield of 76.5% was confirmed by high-performance liquid chromatography (HPLC) analysis. The present study provided an effective method for large-scale production of high purity squalene.     

离子交换树脂对白扦中莽草酸的分离纯化

建立了离子交换树脂分离纯化白扦中莽草酸的工艺条件和参数。通过研究D261、D296、D301-R、D301-G、D290、201*7(717)、D201和D280共8种离子交换树脂对莽草酸的吸附和解吸附能力,筛选出最佳树脂为D290,确定了最佳的吸附与解吸附工艺参数,吸附条件为pH=6、25 ℃、流速为3 mL/min;脱附条件为：洗脱液为2.5%NaOH水溶液,洗脱流速为3 mL/min。莽草酸样品溶液经D290树脂吸附与脱附后回收率为92.53%,纯度由2.97%提高到46.76%,提高了15.74倍。实验结果表明,D290树脂对莽草酸的吸附量大,脱附容易,可以应用于莽草酸的分离纯化。