吸附树脂AB－8对甜菊甙的吸附性能及在其提取纯化中的应用

考察了大孔吸附树脂ＡＢ－８对甜菊甙的吸附性能，和溶液的ｐＨ值、洗脱剂的种类及流速对树脂吸附，脱附性能的影响；结果表明，ＡＢ－８树脂对甜菊甙吸附量高，循环使用性能好且易于洗脱。     

吸附树脂的色层吸附及其在甜菊甙分离纯化中的应用

研究了ADS－7等吸附树脂对甜菊甙各组分的吸附选择性及色层吸附性能,发现ADS－7吸附树脂不仅在吸附甜菊甙时对各个组分呈现出一定的选择吸附顺序,在水洗时还有一定的选择洗脱顺序,这两个顺序正好相反。利用ADS－7吸对脂的这一色层性能,制备了富含甜度最高、味质最好的Rebaudioside A及几科不含色素的高品质甜菊甙,具有很好的实际应用意义。     

大孔吸附树脂合成及从甜叶菊中提取分离甜菊甙的研究

本文合成了一系列用于从甜叶菊提取液中吸附分离甜菊甙的大孔吸附树脂，测定了它们的孔结构参数及吸附量，并比较了吸附量较高的五种树脂的循环使用性能及解吸性能。实验结果表明，Ｍ－３５树脂吸附量大，解吸率高，用树脂法工艺制备的甜菊甙产品纯度高，质量好。     

季铵基吸附树脂的合成及其在甜菊式甙提取分离中的应用

研究了由工业二乙烯苯聚合得到的大孔树脂进行氯甲基化的可行性，考察了聚合物孔结构催化剂用量、反应温度和时间等因素对氯甲基化反应的影响，由氯甲基化树脂制备了强极性季铵基吸附剂。并研究了合成的季铵基吸附剂对甜叶菊提取物中甜菊甙及色素的吸附－脱附性能，发现该吸咐剂对甜菊甙与色素的吸附－脱附性能完全不同，因而可用该吸附剂制备高品质的甜菊式。     

极性修饰的聚苯乙烯吸附树脂的结构和性能

在苯乙烯－二乙烯苯共聚体系中加入甲基丙烯酸甲酯，甲基丙烯酸，丙烯腈和乙酸烯丙酯等等三单体，对吸附树脂表面进行修饰，用物理技术和化学方法表征了合成树脂的结构，测定了它们对甜菊甙的吸附量。结果表明，第三单体的极性和用量等因素对树脂的孔结构和吸附量有较大的影响。     

AB—8树脂对罗汉果皂甙的吸附

本文初步研究了大孔吸附树脂ＡＢ－８对罗汉果皂甙的吸附性能，比较了１５℃和６５℃下的吸附速度，获得了在ＳＶ２、ＳＶ５、ＳＶ８三种空速下的穿漏吸附量。     

交联聚苯乙烯吸附树脂的修饰及其对天然皂甙的吸附性能

交联聚苯乙烯氯甲基化后,将氯转化为羟基、氨基、甲氧基、苯氧基、4-羟基苯氧基和4-乙酰苯氧基,合成了不同极性的吸附树脂Ⅰ—Ⅵ。同时由交联聚苯乙烯经Friedel-Crafts酰化反应在其苯环上引入乙酰基,制备了树指Ⅶ。用物理技术和化学方法表征树脂Ⅰ—Ⅶ的结构,然后测定了它们对天然皂甙如甜菊甙和绞股蓝皂甙的吸附量。结果说明,这些树脂亲水性较好,均能吸附天然皂甙,但只有中极性的酮基树脂Ⅵ和Ⅶ的吸附量较大。     

若干极性树脂对黄芩甙及黄芩黄素的吸附性能研究

测定了35种具有不同极性的吸附树脂对黄芩甙及黄芩黄素的吸附量,发现弱碱树脂具有较大的吸附量,研究了弱碱树脂对黄芩黄素的吸附动力学,观察到该树脂对黄芩黄素的吸附较快,5h已基本达到吸附平衡。     

超高交联吸附树脂柱色谱法分离提纯喜树碱及喜果甙

本文比较了所合成的8种大孔超高交联吸附树脂对喜树果提取液中喜树碱和喜果甙的吸附性能及柱层析分离效果。结果表明，经超高效联树脂的层析分离，喜树碱的质量分数可提高到约15％，喜果甙的质量分数可提高到约60％。     

大孔吸附树脂的合成及其对黄芩甙的吸附性能

用吸附树脂纯化分离中药黄芩中的黄苓甙是天然药物研究新技术。但吸附树脂交联聚苯乙烯疏水性强,水相与树脂之间的界面能较大,通过氯甲基化引入极性基团可以改善树脂的吸附性能。本文通过对氯甲基化后的交联聚苯乙烯(氯球)进行后交联以改善树脂孔结构,并通过胺化反应增加树脂的极性和亲水性,研究所合成一系列大孔吸附树脂的碱基含量对黄苓甙的静态吸附性能的影响。     

基于稀土分离的萃淋树脂制备与应用研究

萃取色层法被称为第二代萃取体系,相对于液-液萃取选择性分离效果更好,萃取剂溶解损失小,被应用于超高纯稀土的制备。萃取色层法的关键是萃淋树脂,决定萃淋树脂性能的关键因素是萃取剂/萃取官能团。按照萃取剂与支撑基底的作用方式不同,萃淋树脂可分为两类:一类是萃取剂通过物理作用负载在支撑物基底上,另一类则是具有萃取作用的官能团通过化学键悬挂在支撑基底上。以萃取剂/萃取官能团为主要切入点,综述了近十年来萃淋树脂的研究进展,阐述了萃淋树脂的制备方法,负载不同萃取剂/悬挂不同萃取官能团的萃淋树脂对RE3+的萃取行为、机制、饱和萃取容量及分离性能等。     

萃淋树脂和螯合树脂在金属元素分离及试剂纯化中的应用

作者等就多年来在萃淋树脂及螯合树脂在金属元素分离及试剂纯化方面所取得的经验和成果作了总结。在萃淋树脂方面,概要地叙述了此类树脂的制备方法,其选择性及应用等内容。就螯合树脂方面几种突出实例,如Chelex 100树脂应用于从碱金属及碱土金属离子溶液中选择性地分离两价重金属;Amberlite 743硼选择性树脂用于选择性分离以BO33-或BF4-形式存在的硼(Ⅲ)离子;LZ 85树脂用于制备高纯度含钴试剂及353E树脂用于吸附分离金属离子与氰根形成的络合离子如Au(CN)4-、Ag(CN)2-等作了介绍。此外,还对应用阴离子交换树脂,如Dowex 1-X8,分离金属离子与氯离子生成的络阴离子,如[AuCl6]3-、[FeCl4]-等;对阳离子交换树脂用于制备高纯铀等特例作了简述。     

Anti-Quorum Sensing Activity of Stevia Extract,Stevioside, Rebaudioside A and Their Aglycon Steviol

Governments are creating regulations for consumers to reduce their sugar intake, prompting companies to increase the ratio of artificial sweeteners in their products. However, there is evidence of some deleterious effects ascribed to the aforementioned synthetic agents and therefore consumers and food manufacturers have turned their attention to natural dietary sweeteners, such as stevia, to meet their sweetening needs. Stevia is generally considered safe; however, emerging scientific evidence has implicated the agent in gut microbial imbalance. In general, regulation of microbial behavior is known to depend highly on signaling molecules via quorum sensing (QS) pathways. This is also true for the gut microbial community. We, therefore, evaluated the possible role of these stevia-based natural sweeteners on this bacterial communication pathway. The use of a commercial stevia herbal supplement resulted in an inhibitory effect on bacterial communication, with no observable bactericidal effect. Purified stevia extracts, including stevioside, rebaudioside A (Reb A), and steviol revealed a molecular interaction, and possible interruption of Gram-negative bacterial communication, via either the LasR or RhlR receptor. Our in-silico analyses suggest a competitive-type inhibitory role for steviol, while Reb A and stevioside are likely to inhibit LasR-mediated QS in a non-competitive manner. These results suggest the need for further safety studies on the agents.     

Separation and Purification of Glufosinate Through Combination of an Electrodialysis Membrane and a Macroporous Adsorption Resin

Glufosinate is a nonselective organophosphorus herbicide with low toxicity and high efficiency that is widely used in forestry, agriculture and other industries. In the process of manufacturing glufosinate, large amounts of ammonium chloride and coloured organic impurities are generated. Because of its high solubility in water, separation of glufosinate from inorganic salts is extremely difficult. Hence, a co-separation method combining an electrodialysis membrane and a macroporous adsorption resin was developed to obtain glufosinate with higlier purity. For the electrodialysis process, a glufosinate reaction solution was placed in a dilute chamber and desalinated. The concentration of inorganic salts in the resultant glufosinate aqueous solution was only 0.99 g/L under the optimal conditions of an operating voltage and a volume ratio of 9 V and 1:1, respectively. For the macroporous resin adsorption/desorption process, the sample solution treated by electrodialysis was pumped into the resin-filled column, which was eluted to obtain the eluent when the adsorption reached equilibrium. Consequently, nearly all the coloured organic impurities were removed under the optimal conditions, in which the resin type, pH value, flow rate, glufosinate concentration, temperature, ratio of ethanol and volume of eluent were LX-300C,3,0.5 mL·cm^2·min^-1,20 mg/mL,25℃, 50% and 400 mL, respectively. After the electrodialysis and adsorption/desorption process, the purity of the glufosinate was increased to 95.14%, and its recovery rate was as high as 98%. The advantages of this process included its ease of operation, environmental friendliness and low cost, which provided strong potential for its use in industrial applications.     

固相萃取分离铀

铀是重要的核工业原料,也是一种有较强化学和生物毒性的重金属。从各类含铀水体系中分离和回收铀对缓解铀资源短缺,保护人类健康和生态环境安全都具有重要的科学和实际意义。本文简要回顾和评述了近15年来具有代表性的新型固相萃取材料及其在铀分离方面的应用研究,并对相关材料在铀分离领域的应用前景进行了分析和展望。     

甜叶菊糖的组份分离与味质改进研究进展

对甜菊叶提取物中甜菊甙及甜双匝糖甙相关物的组分离，测定以及为改进味质采用的酶转糖基化法，等手段进行概要评述。     

胺化超高交联吸附树脂的制备及其对喜树碱和喜果苷的色谱分离

胺化超高交联吸附树脂的制备及其对喜树碱和喜果苷的色谱分离;喜树碱;喜果苷;胺化超高交联吸附树脂;吸附性能;层析分离     

Study on Adsorption and Separation of Naringin with Macroporous Resin

X-5 resin, with higher adsorption and easier desorption of naringin, was selected from five kinds of macroporous resins through static adsorption and desorption experiments. Effects of concentration, pH value, and flow rate of naringin extract on the adsorption of naringin by X-5 resin were studied. Meanwhile, the effect of these factors on the desorption of naringin from X-5 resin was also investigated. The experimental results show that the adsorption isotherm of naringin by X-5 resin can be described by the Langmuir isotherm equation. The static maximum adsorption capacity of naringin is 32.6 mg/g with naringin concentration at 2.7 g/L, while the dynamic adsorption capacity of naringin is 23.8 mg/g with naringin extract flow rate at two times that of resin volume per hour. The optimal eluant is 60% (v/v) ethanol-water with pH value of 10. The desorption ratio will rise to more than 85% when the flow rate of this optimal eluant is one to two times that of resin volume per hour. Translated from Journal of Central South University (Science and Technology)     

Stevioside Activates AMPK to Suppress Inflammation in Macrophages and Protects Mice from LPS-Induced Lethal Shock

Stevioside, a diterpenoid glycoside, is widely used as a natural sweetener; meanwhile, it has been proven to possess various pharmacological properties as well. However, until now there were no comprehensive evaluations focused on the anti-inflammatory activity of stevioside. Thus, the anti-inflammatory activities of stevioside, both in macrophages (RAW 264.7 cells, THP-1 cells, and mouse peritoneal macrophages) and in mice, were extensively investigated for the potential application of stevioside as a novel anti-inflammatory agent. The results showed that stevioside was capable of down-regulating lipopolysaccharide (LPS)-induced expression and production of pro-inflammatory cytokines and mediators in macrophages from different sources, such as IL-6, TNF-α, IL-1β, iNOS/NO, COX2, and HMGB1, whereas it up-regulated the anti-inflammatory cytokines IL-10 and TGF-β1. Further investigation showed that stevioside could activate the AMPK -mediated inhibition of IRF5 and NF-κB pathways. Similarly, in mice with LPS-induced lethal shock, stevioside inhibited release of pro-inflammatory factors, enhanced production of IL-10, and increased the survival rate of mice. More importantly, stevioside was also shown to activate AMPK in the periphery blood mononuclear cells of mice. Together, these results indicated that stevioside could significantly attenuate LPS-induced inflammatory responses both in vitro and in vivo through regulating several signaling pathways. These findings further strengthened the evidence that stevioside may be developed into a therapeutic agent against inflammatory diseases.