高比表面季铵基树脂的结构调控及在三七叶总皂甙纯化中的应用研究

利用Davankov后交联反应,合成了一类兼具高比表面积和高功能基含量的季铵基(—N+(CH)3)吸附树脂,考察了树脂比表面积和功能基含量的调控规律,并将其用于三七叶总皂甙的进一步纯化.结果表明,当树脂比表面积为692m2/g,交换量为2.1mmol/g时,树脂具有最佳的纯化效果,只通过吸附—解吸一步工艺,产品纯度即可从32.0%提高到90%以上,皂甙的回收率高于95%.最后,初步探讨了树脂对皂甙和色素的吸附机理,认为树脂对皂甙的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应.     

吸附树脂法在泽泻提取物的脱色及高纯度泽泻醇制备中的应用研究

将具有脱色和吸附双重功能的新型吸附树脂用于泽泻提取物的脱色和高纯度泽泻醇提取物的制备工艺中,考察了树脂结构对脱色性能和吸附性能的影响熹见律.结果表明,兼具适宜的比表面积和功能基含量的No.2树脂具有最佳的纯化效果,只通过"吸附-解吸"一步工艺,产品纯度即可从1.93%提高到50%以上,泽泻醇的回收率高于95%.初步探讨了树脂的吸附机理,认为树脂对泽泻醇的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应.     

大孔交联聚(对乙烯基苄基苯胺)树脂对苯酚的吸附

由氯甲基化聚苯乙烯合成了大孔交联聚(对乙烯基苄基苯胺)树脂, 测定了其对正己烷和水中苯酚的吸附等温线, 计算了吸附焓. 结果表明, 苯胺基树脂主要是通过氢键吸附正己烷中苯酚的, 树脂负载的功能基氮原子和苯环都作为氢键受体与苯酚的羟基氢原子形成氢键, 而其对水中苯酚的吸附是基于氢键和疏水作用.     

高比表面极性大孔树脂的结构设计及在甜菊糖Rebaudioside D苷分离中的应用

基于高交联聚苯乙烯树脂骨架上悬挂双键的二次引发,设计合成了一类弱极性酯基功能基含量较高且兼具高比表面积的新型大孔吸附树脂,在吸附分离中表现出偶极-疏水协同作用机制,用于甜菊糖中结构相近的单体糖苷Rebaudioside D (简称RD)的分离纯化,克服了传统吸附树脂的选择性和吸附容量不能兼顾的缺点,对甜菊糖粗提物纯化后,RD苷的纯度由7.1%提高到51.2%。     

不同长度酰胺基手臂吸附树脂对罗布麻黄酮吸附纯化研究

二乙烯苯交联的酯基树脂分别与乙二胺、二乙烯三胺、三乙烯四胺、四乙烯五胺发生胺解反应,将其胺端与乙酸酐进行酰化得到不同长度手臂的酰胺树脂,研究了其对罗布麻黄酮的纯化,发现二乙烯三胺手臂的酰胺树脂对黄酮选择性最好,将罗布麻黄酮纯度从17%提高到80%。利用吸附热力学研究其吸附机理,树脂对黄酮的等量吸附焓在氢键吸附范围内。通过红外光谱测定,发现树脂吸附罗布麻黄酮前后,酰胺基团的伸缩振动峰由1624.5cm~(-1)移动到了1619.6cm~(-1),移动了5个波长,说明酰胺树脂的酰胺基团与多酚类的黄酮分子之间形成了氢键作用,增强了其对黄酮化合物吸附选择性。     

川佛手黄酮类物质的分离纯化和抗氧化活性研究

采用微波和超声波联合提取技术提取川佛手中的黄酮.通过对大孔吸附树脂种类和洗脱液浓度条件优化,获得了最佳实验参数.在此基础上,选择D101树脂,通过石油醚、水和无水乙醇梯度洗脱对川佛手黄酮粗提物进行了分离纯化,得到川佛手黄酮纯化物纯度为92.65%.将川佛手黄酮粗产物、纯化产物、Vc和芦丁进行了抗氧化比较研究,川佛手黄酮纯化产物对DPPH·和·OH的清除率分别可达到82.22%和69.46%,结果表明川佛手黄酮纯化产物具有较好的清除自由基能力和较强的抗氧化活性.     

大孔吸附树脂对罗布麻叶中总黄酮的纯化研究

比较了HPD100,HPD400,HPD500,HPD600和HPD826等5种吸附树脂对罗布麻总黄酮的吸附选择性,在静态和动态吸附基础上筛选出效果较好的HPD100树脂,探讨了洗脱液乙醇浓度对黄酮纯化的影响,得到一次粗提物黄酮纯度为17.2%,为初始纯度的3.5倍。为了提高树脂对黄酮选择性,制备了4种二乙烯苯(DVB)含量不同的酰胺树脂,并对树脂进行了表征。以AB8树脂为对比,将酰胺树脂用于罗布麻黄酮的二次纯化,发现40%DVB含量的酰胺树脂纯化效果最好,考察了洗脱液乙醇浓度,上柱液乙醇浓度,上柱液黄酮浓度等吸附洗脱条件对黄酮纯化效果的影响,获得最佳纯化条件,在2BV/h的流速下,上柱液乙醇浓度为15%(V:V),洗脱液乙醇浓度为80%(V:V),上柱液黄酮浓度为2.02mg/mL,上柱体积为2BV。HPLC测定黄酮纯度为72.5%,是一次粗提物黄酮纯度的4.3倍,为初始纯度的14.8倍。     

二乙烯苯-异氰酸三烯丙基酯-丙烯腈共聚物大孔树脂对原花青素的吸附

根据原花青素含有疏水性的苯环和酚羟基的特点,设计合成了含有苯环和酰胺基的大孔二乙烯苯-异氰酸三烯丙基酯-丙烯腈(DTA)共聚物吸附树脂,DTA树脂通过疏水作用和氢键吸附原花青素.比较了DTA吸附树脂和3种商品化吸附树脂ADS-5(非极性)、ADS-8(弱极性)和ADS-17(中极性)对原花青素的吸附性能.结果表明,DTA、ADS-8、ADS-17对原花青素的吸附既包含疏水作用又有氢键参与.在合适的单体和致孔剂配比情况下合成的DTA吸附树脂对原花青素有很好的吸附性能.     

分子烙印技术在沙棘功效成分提取中的应用

槲皮素和异鼠李素为黄酮类物质，是中药沙棘治疗和预防多种心血管疾病的主要功效成分.作者制备了以槲皮素为模板的分子烙印聚合物（MIP），从沙棘粗提物中分离提取这两种黄酮，得到良好的效果.     

邻胺基-羟基吸附树脂的制备及其对羟基红花黄色素HSYA的纯化效果研究

合成了结构均匀的、具有邻胺基-羟基的吸附树脂poly(GMA-co-TMPTMA),简称GT树脂。将GT树脂应用于红花中羟基红花黄色素A(HSYA)的纯化,羟基的氢键作用由于邻位胺基酸碱作用的协同而极大增强,有效弥补了疏水协同作用的不足,对高亲水性HSYA的吸附容量和吸附选择性均显著提高。基于HSYA的高度亲水性,建立了常规聚苯乙烯型大孔吸附树脂XAD-4与GT-70A树脂联用工艺,在连续的闭路体系中完成了红花中HSYA的高纯度提取,产品中HSYA含量达到78.1%,该纯化工艺重现性好、操作简便、易于大规模工业化生产。     

Synthesis of new hydrophobic adsorbents based on homologous series of uncharged alkyl sulphide agarose derivatives

A homologous series of uncharged thioalkyl derivatives of agarose were prepared by a simplified synthetic route and their adsorption behaviour towards human serum proteins was evaluated and compared with that of a commercially available alkyl ether derivative of agarose. The influence of the spacer arm length on the adsorption efficiency was also investigated. The degree of substitution of the derivatives can be estimated conveniently by sulphur analysis. The four different types of thiolkyl derivatives (C6, C8, C12 and C14) investigated here behave in all respects like hydrophobic adsorbents. The coupling yield obtained is high (75% or more) and is better than that obtained by alternative synthetic routes reported so far. The adsorption capacity towards serum proteins of the various derivatives increases with increasing alkyl chain length and degree of substitution. Desorption is achieved by a progressive decrease in the polarity of the eluent and the recovery of the applied material is in the range 80-90%. The role played by the thioether as a possible modulator of the observed hydrophobic adsorption is discussed. For the group separation of serum proteins the optimum adsorbent, as regards capacity combined with ease of elution of adsorbed material, should be substituted with chains of six or eight carbon atoms and have a ligand concentration in the range 80-120 mumole g-1 dry gel.     

High selective purification of flavonoids from natural plants based on polymeric adsorbent with hydrogen-bonding interaction

The efficient purification method of high purity flavonoids from natural plants was reported. A series of polymeric adsorbents with novel structure were synthesized based on the copolymerization of methyl acrylate (MA) and ethylene glycol dimethacrylate (EDGMA). Functional groups, such as ester, amino or amide group, were introduced into the adsorbent matrix, respectively, to produce the hydrogen-bonding interaction and enhance the adsorption selectivity towards flavone compounds. The influences of matrix structure and functional groups of synthesized adsorbents on the adsorption selectivity were investigated. The resins were applied to purify flavonoids in natural plants. It was illuminated that the adsorbent No. 3B with 15% EGDMA content and amide groups performed optimal selectivity to flavone compounds in Scutellaria barbata D.Don, from which the purity of flavonoids in extracts was obtained more than 50%, obviously higher than that from commercial adsorbents. The result of adsorption thermodynamics experiment showed that the isosteric adsorption enthalpy of No. 3B was in the range of 25–30 kJ/mol, which testified that the adsorption mechanism was related to hydrogen-bonding interaction. The method showed its universality via good effects on the purification of total flavonoids from Ginkgo biloba L., Radix puerariae and Hypericum perforatum L.     

寡肽吸附剂的制备及吸附机理

为清除尿毒症患者血清中分离出的八肽VVRGCTWW(V8), 制备了不同间隔臂长含苯环的吸附剂Phenc. 吸附实验结果显示, 吸附剂Phe3c具有非常好的吸附能力. 采用NMR和分子模拟技术对吸附剂的模型体系的吸附机理进行了研究. 结果显示, 配体中的苯环可与八肽形成π-π堆积, 而且间隔臂的增长可以克服空间位阻效应, 有效增加配体与V8的作用几率, 进而增强吸附剂与八肽的相互作用. 研究结果表明, 采用合理的分子模型及分子对接方法, 不仅可以合理解释吸附剂的吸附机理, 而且可用于吸附剂的虚拟筛选.     

树脂填充EVAL纤维吸附剂的制备及其吸附性能表征

采用具有亲水性的乙烯-乙烯醇共聚物(EVAL)作为纤维吸附剂基质材料,粉末型Lewatit阳离子交换树脂CNP80ws为功能材料,采用可控相分离方法,制备了不同表面形态结构的树脂填充EVAL吸附剂.当使用外部液体调控相分离过程时,在纤维的表面形成了粗糙的开孔结构,并且随树脂的填充量提高纤维表面的粗糙度与开孔度有所提高.研究结果表明:树脂填充EVAL纤维吸附剂具有较大的吸附容量与较高的脱附率,其吸附容量不低于53.9mg BSA/g吸附剂(树脂填充量50%).     

Dendrimer PAMAM为手臂的LDL吸附剂制备及性能研究

树状高分子聚酰胺-胺(Dendrimer PAMAM)是一种具有大量活泼氨基末端的对称大分子.通过官能团转化,可将其变为具有不同端基的新性能的树状高分子.本文研究了不同代数的Dendrimer PAMAM作为血液净化吸附剂的"手臂"对配基牛磺酸的连接和对LDL吸附性能的影响.初步研究树状高分子的手臂效应,证明使用枝化手臂是一种能提高吸附剂吸附性能的有效方法.     

EFFECT OF pH ON THE ADSORPTION OF p-AMINOBENZOIC ACID ON POLYSTYRENE-BASED ADSORBENTS

In the present study the adsorptive properties of p-aminobenzoic acid with hypercrosslinked and multi-functional polymeric adsorbents at different solution pHs were systematically investigated in accordance with the particular physicochemical characteristics of the aromatic amphoteric compound involving both Lewis acid and Lewis base functional groups. It was found that the equilibrium adsorption data of the three polymeric adsorbents fitted well in the Langmuir and Freundlich isotherm equations. Studies at various pH levels indicate that the capacity of the adsorbents for adsorption of the ionic forms of adsorbate is less than that for the corresponding neutral species. At pH 3.78, the adsorption capacities of the three adsorbents are the highest. Whereas the adsorption property of multi-functional polymeric adsorbent NJ-99 is the largest, which may be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of p-aminobenzoic acid. The trend of the adsorption capacities of the three adsorbents towards p-aminobenzoic acid with the solution pH is in accord with the dissociation curve of the neutral molecular p-aminobenzoic acid. The adsorption forces include π-π interaction, hydrogen-bonding interaction and electrostatic attraction or repulsion when there exist the molecular and ionic adsorbing species at different pHs in aqueous solution.     

Comparison of the protein adsorption selectivity of salt-promoted agarose-based adsorbents: Hydrophobic, thiophilic and electron donor–acceptor adsorbents

Protein adsorption of human serum onto six different agarose-based chromatographic gels that were representative of the salt-promoted adsorbent family [octyl- and phenyl-Sepharose, mercaptoethanol–divinyl sulfone agarose (T gel), mercaptomethylene pyridine-derivatized agarose gel (MP gel), tricyanoaminopropene–divinyl sulfone agarose (DVS–TCP gel), tricyanoamino-propene–bisoxirane agarose (bisoxirane–TCP gel)] was studied in the presence of moderate or high concentrations of the water structuring salt, sodium sulfate. Study of the protein adsorption selectivity by two-dimensional gel electrophoresis revealed an opposed selectivity for hydrophobic interaction adsorbents and electron donor–acceptor adsorbents. The T gel, MP gel and TCP gels belonged to the electron donor–acceptor adsorbents, displaying a main selectivity for immunoglobulins, whereas octyl-Sepharose belonged to the hydrophobic adsorbents, displaying a main selectivity for ‘hydrophobic' proteins. Phenyl-Sepharose for its part was described as an example of a composite selectivity of both families. The conclusion of this work is two-fold: (1) hydrophobic interaction chromatography (HIC) and electron donor–acceptor chromatography (EDAC) have opposed protein selectivities and are both salt-promoted. As a main consequence, it means that high concentrations of a water-structuring salt can promote different types of weak molecular interactions, resulting in different protein adsorption selectivities: (2) thiophilic adsorption chromatography (TAC) should be renamed EDAC as similar protein selectivity is demonstrated for electron donor–acceptor ligand devoid of sulfur atoms.     

Selective removal of caffeine from tea extracts using macroporous crosslinked polyvinyl alcohol adsorbents

The hydrolysis reaction of ester groups in vinyl acetate (VAc) was used to introduce hydroxyl groups into the matrix of a macroporous adsorbent, which was itself prepared by free radical suspension copolymerization of triallyl isocyanurate (TAIC) and VAc. Therefore, the copolymerization incompatibility between the hydrophilic and the hydrophobic monomer was overcome successfully and the hydrophobic matrix of the polymeric adsorbent containing a polyvinyl alcohol (PVA) segment was obtained. Introduction of the PVA segment decreased the hydrophobic adsorption affinity of the adsorbent while producing the hydrogen-bonding interaction. When isolating the two active components, polyphenols (TPh) and caffeine (CAF), from green tea extracts, this polymeric adsorbent, namely poly(TAIC-co-VA), exhibited good adsorption selectivity towards TPh over CAF. The adsorption mechanism leading to this selectivity involved a hydrophobic interaction mechanism for CAF and multiple weak hydrophobic and hydrogen-bonding interactions for TPh. The adsorption thermodynamics for TPh on poly(TAIC-co-VA) were studied. The effects of adsorbent structure and gradient desorption conditions on isolation were investigated. The result showed that adsorbent, with 20% TAIC content, was able to efficiently remove CAF from different tea extracts with different ratios of TPh and CAF. Finally, almost no CAF was detected in the TPh fraction and the recovery of TPh was greater than 95%.     

Microcalorimetric studies of interactions between proteins and hydrophobic ligands in hydrophobic interaction chromatography: effects of ligand chain length, density and the amount of bound protein

Using isothermal titration calorimetry (ITC), this investigation directly measured the adsorption enthalpies of proteins on various hydrophobic adsorbents. Various amounts of butyl and octyl groups were attached onto CM-Sepharose to form C4 and C8, two types of hydrophobic adsorbents. The adsorption enthalpies of both trypsinogen and alpha-chymotrypsinogen A were measured at 4.0 M NaCl and pH 10.0, in which most ionic interaction was suppressed. The adsorption isotherms of both proteins on various adsorbents were also measured, thus allowing us to calculate the Gibbs free energy and entropy of adsorption. Experimental results indicated that the adsorption of both proteins on butyl-containing adsorbents was exothermic, while their adsorption on octyl ones was endothermic. In addition, binding of both proteins with the butyl ligand is basically an adsorption process, while binding with the octyl ligand is adsorption and partition processes. Moreover, on both butyl or octyl, the adsorption enthalpy became increasingly positive as the ligand density increased, while the adsorption entropy became more positive as the alkyl chain length or density of the adsorbent increased. In addition, ITC was used to measure protein-protein interaction. The adsorption enthalpy of both proteins increased as the amount of bound protein increased, and the enthalpy increase of trypsinogen appeared to be higher than that of alpha-chymotrypsinogen A. This observation implies that protein-protein repulsion was stronger among trypsinogen molecules in the experiments.