反胶团系统及蛋白质萃取过程研究进展

综述了反胶团系统和蛋白质萃取过程,将反胶团萃取系统按单一反胶团系统、混合反胶团系统和亲和反胶团系统划分,强调了研究开发生物相容性表面活性剂以及在反胶团系统中引入亲和作用的重要性。另外,指出了深入开展反胶团萃取设备和过程研究的必要性。     

Chlorophyllase biocatalysis in an aqueous/miscible organic solvent medium containing canola oil

Chlorophyllase catalyzes the bioconversion of chlorophyll into chlorophyllide by replacing the phytol group with a hydrogen atom. There is an increased interest in the biotechnological application of chlorophyllase for the removal of green pigments from edible oil and its potential as an alternative to the use of the conventional bleaching technique. Partially purified chlorophyllase, obtained from the alga Phaeodactylum tricornutum, was assayed for its hydrolytic activity in an aqueous/miscible organic solvent system containing refined-bleached-deodorized (RBD) canola oil, using chlorophyll and pheophytin as substrate models. The results indicated that chlorophyllase biocatalysis could be successfully carried out in an aqueous/miscible organic system containing RBD canola oil. The presence of 20% RBD canola oil decreased the hydrolytic activity of chlorophyllase by 2.2 and 6.7 times, using chlorophyll and pheophytin as substrates, respectively. In addition, acetone acted as an activator of chlorophyllase activity at low concentrations and an inhibitor at higher ones. The optimal reaction conditions for chlorophyllase biocatalysis in the aqueous/miscible organic system were determined to consist of 20% RBD oil and 10% acetone at a 200 rpm agitation speed and at a temperature and substrate concentration of 35°C and 12.6 μM for chlorophyll, and 30°C and 9.3 μM for pheophytin.     

Continuous Countercurrent Extractive Biocatalysis in Aqueous Surfactant Two‐Phase Systems

To evaluate the possibility of performing extractive biocatalysis in continuous mode, the hydrolysis of penicillin G in a micellar solution containing the nonionic surfactant Tergitol NP‐7 was chosen as model system. While the product phenylacetic acid distributes into the micellar phase, 6‐aminopenicillanic acid moves preferably into the aqueous phase. The yield in the continuous multi‐step process was higher in comparison to equivalent batch systems. Overall, the results demonstrate the suitability of aqueous surfactant two‐phase systems for continuous biocatalytic reactive extraction processes.     

生物催化在环保中的应用进展

对生物催化剂在环境保护中的应用进行了阐述。具体描述了生物除污和生物产能两个方面。其中前者包括微生物的生物除污和酶生物除污,后者包括生产生物柴油、生物乙醇、生物氢和生物燃料电池。     

选择性腈水解酶在生物催化中的应用

腈水解酶作为生物催化剂水解腈类化合物,具有高效性、高选择性、反应条件温和、环境污染小、成本低等优点。本文综述了腈水解酶的化学、区域及立体选择性在生物合成中的广泛应用。     

胶束扫集毛细管电动色谱用于实验教学初探

现代职业教育提倡"教学做一体化"的教学模式,针对液相色谱设备昂贵,实验消耗多,教学成本较高等问题,首次提出在色谱分析基础实验教学中应用胶束扫集毛细管电动色谱技术,单次实验成本降低到约为高效液相色谱法的百分之一,大大提高实验经费使用效率,增加学生实践机会。并从方法原理、实验目的、实验方法设计、数据记录及处理等方面开展实例探讨。     

Optimization of the Biocatalysis for D-DIBOA Synthesis Using a Quick and Sensitive New Spectrophotometric Quantification Method

D-DIBOA (4-hydroxy-(2H)-1,4-benzoxazin-3-(4H)-one) is an allelopathic-derived compound with interesting herbicidal, fungicidal, and insecticide properties whose production has been successfully achieved by biocatalysis using a genetically engineered Escherichia coli strain. However, improvement and scaling-up of this process are hampered by the current methodology for D-DIBOA quantification, which is based on high-performance liquid chromatographic (HPLC), a time-consuming technique that requires expensive equipment and the use of environmentally unsafe solvents. In this work, we established and validated a rapid, simple, and sensitive spectrophotometric method for the quantification of the D-DIBOA produced by whole-cell biocatalysis, with limits of detection and quantification of 0.0165 and 0.0501 µmol·mL⁻¹ respectively. This analysis takes place in only a few seconds and can be carried out using 100 µL of the sample in a microtiter plate reader. We performed several whole-cell biocatalysis strategies to optimize the process by monitoring D-DIBOA production every hour to keep control of both precursor and D-DIBOA concentrations in the bioreactor. These experiments allowed increasing the D-DIBOA production from the previously reported 5.01 mM up to 7.17 mM (43% increase). This methodology will facilitate processes such as the optimization of the biocatalyst, the scaling up, and the downstream purification.     

生物催化技术在化学工业中的应用（一）

化学工业在尝试使用可再生的原料以改善其持续性 ,促使化学品生产中生物加工的探索。生物系统吸引人的特征包括多样性、酶作用物选择性、区域选择性、化学选择性、对映体选择性以及在温和环境温度和压力下的催化作用。然而 ,生物加工的问题在于同化学加工的成本竞争 ,因为与现行的工业化生产过程对应的资产成本是很高的。化学工业可能会将生物技术运用于现有的原料和生产过程中 ,以从原料、加工副产物及废弃物中获取更多的好处。在今后的 10年间 ,能提供优于传统化学路线的生产过程或产品的生物加工将被更为广泛地应用。本文综述了环烷酮、烷基芳香烃、腈的生物转化 ,生物的芳香烃羧化作用和葡萄糖制 1,3 丙二醇     

Biocatalysis of tyrosinase in chloroform medium,using selected phenolic substrates

The biocatalysis of mushroom tyrosinase was optimized in chloroform medium using as substrates selected phenolic compounds, including chlorogenic acid (CA), p‐aminophenol (pAP) and hydroquinone (HQ). The specific activity of tyrosinase was found to be much higher in the chloroform medium than that obtained in the aqueous one. The optimal pH and temperature as well as other kinetic parameters for tyrosinase biocatalysis was also determined. The presence of catechol in the chloroform medium resulted in an increase in tyrosinase activity when CA was used as substrate; however, no activatory effect was found with pAP or HQ. The presence of ethylenediamine tetraacetic acid in the chloroform medium showed different effects on tyrosinase activity depending on the nature of the substrate. FT‐IR analyses confirmed the bioconversion of selected phenolic substrates into o‐quinones by tyrosinase activity in the chloroform medium. © 2000 Society of Chemical Industry     

新型磷–氮–卤三系阻燃剂的合成及其在PP中的应用

五硫化二磷、对卤苯酚和二乙胺经过两步反应,合成了两种新型磷–氮–卤三系阻燃剂:O,O’–二(4–卤代苯基)二硫代磷酸–N,N–二乙铵(4–XC_6H_4O)_2PS_2NH_2Et_2[X=Br(1),Cl(2)],用元素分析、傅里叶变换红外光谱、核磁共振氢谱、紫外–可见吸收光谱和热重分析测定了两种阻燃剂的结构和热稳定性,并测定了它们在聚丙烯(PP)材料中的阻燃性能。热分析结果表明:两种阻燃剂的热稳定高,热分解温度分别为234.8℃和200.7℃;阻燃剂在PP中的质量分数为30%时,两种阻燃剂的极限氧指数(LOI)分别为28.5%和27.1%,垂直燃烧等级达到UL94 V–0级,表明所合成的两种阻燃剂具有良好的阻燃性能和潜在应用前景。     

生物催化在农药合成中的应用

对现有农药进行结构修饰及制备光学纯的手性农药是当前农药研究开发的重要内容,其中常涉及很多高选择性反应步骤,采用传统化学方法往往操作复杂、成本高并可能造成环境污染。生物催化具有反应条件温和、高效、高选择性及低污染等优点,成为化学催化的重要补充。近年来,生物催化在农药合成中的应用日益受到关注。介绍了生物催化在农药分子的选择性结构修饰及手性农药去消旋化等方面的研究及应用情况。     

Biocatalysis at Work: Applications in the Development of Sagopilone

For the antitumour agent sagopilone, an epothilone analogue, a large‐scale synthesis was developed to synthesise the active pharmaceutical ingredient for clinical trials, exploring enzymatic and microbial methods to produce chiral building blocks on a multi‐kilogram scale. The three building blocks were identified as key intermediates in the synthesis and needed to be produced with high optical purity in yields higher than those previously published. The improved syntheses of two of these building blocks are detailed herein. For building block A, the chemical research synthesis was abandoned, and a novel chemical route was developed leading to building block A via an enzymatic hydrolysis process. For building blocks C, replacement of a chemical catalytic procedure by a microbial process meant that the development of a new starting material could be avoided, thereby accelerating the development process. For the clinical development process, a human metabolite of sagopilone was required as a reference. To accelerate the synthesis of the metabolite, no chemical synthesis was investigated; rather, we relied solely on oxidoreductases. The human metabolite of sagopilone was synthesised on a multi‐gram scale in a single‐step process using genetically engineered E. coli expressing human cytochrome P450 enzyme 2C19. The integration of enzymatic and microbial processes provided tools that enable the synthesis of highly functionalised intermediates and metabolites.     

胶束液相色谱法测定尿液中布洛芬的含量

建立了布洛芬在尿液中的胶束液相色谱测定方法。采用ZORBAX Extend-C18色谱柱（4.6 mm×250 mm,5μm）,流动相为含20 mmol/L Tween-80和25 mmol/L K2HPO4的胶束溶液,pH 7.8,检测波长为263 nm,流速为1.5 mL/min,柱温为30℃,进样量为20μL。结果尿液中布洛芬的回收率大于97%,在0.2 mg/mL和1.0 mg/mL范围内线性良好,r值高于0.999,24 h内RSD值为3.2%。该方法绿色环保、简便、准确、灵敏、经济,可用于分析尿液中布洛芬的分析测定。     

二茂铁表面活性剂电化学行为的胶束效应

采用循环伏安法研究了具有可逆特性的二茂铁表面活性剂Fc12在pH值为2的0.1 mol·L-1 Li2SO4溶液中的电化学行为的胶束效应,讨论了扫描速度及底物浓度对Fc12电化学行为的影响.结果表明,Fc12具有良好的可逆变化特性,可在氧化态(I2+)与还原态(I+)之间实现自由转换; Fc12在玻碳电极上的峰电流(Ipc)与扫描速度的平方根呈线性关系(R=0.997),说明Fc12的电化学行为是受扩散控制的可逆过程;Ipc和扩散系数(D)在Fc12的临界胶束浓度(CMC)附近出现突变,Ipc和D随Fc12单体的浓度变化较快,超过CMC后,Ipc与D随表面活性剂浓度缓慢变化,与Fc12表面张力变化趋势相吻合.     

胶束毛细管电泳法测定有机磷农药的研究

本论文着重研究了毛细管胶束电泳-紫外检测氧乐果、乐果、敌百虫的分析方法。采用胶束电动毛细管色谱法(MEKC)技术对这三种有机磷农药进行分离,并研究了分析电压、表面活性剂十二烷基硫酸钠(SDS)、电泳缓冲溶液浓度、有机改性剂(甲醇)、进样时间及pH值等对分离测定的影响。当分离电压为20kV,检测波长195nm,在pH值为8.50的150mmol/L硼砂-150mmol/L硼酸的缓冲液与11mmol/L十二烷基硫酸钠和4%甲醇的混合溶液中,在30mbar下进样15s的最佳条件下,3种有机磷农药在最短时间内达到基线分离。在优化条件下,用MEKC方法进行测试。它们的检测限分别为0.11μg/ml、0.06μg/ml、0.10μg/ml。迁移时间和峰高的变异系数分别为0.75%～1.9%、0.44%～0.76%。     

阳离子表面活性剂胶束体系中反离子缔合度的测定

用离子选择电极法和电导法测定了阳离子表面活性剂胶束溶液中的反离子缔合度。结果表明,离子选择电极法测出的数据可靠。     

胶团催化在化学反应中的应用研究进展

胶团催化是近年在有机合成领域迅速发展起来的一项催化技术。该文综述了胶团催化在催化加氢、氧化、水解和亲核取代等有机反应中的应用现状,简要介绍了小分子有机物、电解质和可溶性高分子化合物的加入对胶团催化的影响,展望了胶团催化的发展趋势。引用文献13篇。     

三元链状分子系统液液平衡的Monte Carlo模拟和分子热力学模型

在格子模型基础上,采用构型偏倚蒸发法（CBVM）对三元链状分子系统的液液平衡进行了Monte Carlo模拟,分别考查了分子链长和链节间相互作用参数对相区的影响。模拟发现,在保持交换能参数一定的情况下,互溶区随高分子之一的链长的增加而减小。在各组分链长不变的情况下,分相区随交换能的减小而增加。修正的Freed模型（RFT）可较满意地再现模拟结果,而Ftory—Huggins模型总是过低地估计互溶区。RFT模型可满意地关联和预测苯-庚烷-二甘醇系统的二元和三元液-液平衡数据。     

The Oxidation of Hydrophobic Aromatic Substrates by Using a Variant of the P450 Monooxygenase CYP101B1

The cytochrome P450 monooxygenase CYP101B1, from a Novosphingobium bacterium is able to bind and oxidise aromatic substrates but at a lower activity and efficiency than norisoprenoids and monoterpenoid esters. Histidine 85 of CYP101B1 aligns with tyrosine 96 of CYP101A1, which, in the latter enzyme forms the only hydrophilic interaction with its substrate, camphor. The histidine residue of CYP101B1 was mutated to phenylalanine with the aim of improving the activity of the enzyme for hydrophobic substrates. The H85F mutant lowered the binding affinity and activity of the enzyme for β-ionone and altered the oxidation selectivity. This variant also showed enhanced affinity and activity towards alkylbenzenes, styrenes and methylnaphthalenes. For example the rate of product formation for acenaphthene oxidation was improved sixfold to 245 nmol per nmol CYP per min. Certain disubstituted naphthalenes and substrates, such as phenylcyclohexane and biphenyls, were oxidised with lower activity by the H85F variant. Variants at H85 (A and G) designed to introduce additional space into the active site so as to accommodate these larger substrates did not improve the oxidation activity. As the H85F mutant of CYP101B1 improved the oxidation of hydrophobic substrates, this residue is likely to be in the substrate binding pocket or the access channel of the enzyme. The side chain of the histidine might interact with the carbonyl groups of the favoured norisoprenoid substrates of CYP101B1.