Light‐Driven Kinetic Resolution of α‐Functionalized Carboxylic Acids Enabled by an Engineered Fatty Acid Photodecarboxylase

Chiral α‐functionalized carboxylic acids are valuable precursors for a variety of medicines and natural products. Herein, we described an engineered fatty acid photodecarboxylase (CvFAP)‐catalyzed kinetic resolution of α‐amino acids and α‐hydroxy acids, which provides the unreacted R‐configured substrates with high yields and excellent stereoselectivity (ee up to 99 %). This efficient light‐driven process requires neither NADPH recycling nor prior preparation of esters, which were required in previous biocatalytic approaches. The structure‐guided engineering strategy is based on the scanning of large amino acids at hotspots to narrow the substrate binding tunnel. To the best of our knowledge, this is the first example of asymmetric catalysis by an engineered CvFAP.     

Ce(IV) ion initiated graft polymerization of glycidylmethacrylate onto a demineralized bone matrix: effect of reaction parameters

Studies on chemical modification of demineralized bone matrix (DBM) have opened new arenas in the field of clinical orthopedics owing to its potential osteoinductivity with desired chemical functionality. To widen its usage to biomolecular delivery, graft polymerization of glycidylmethacrylate onto DBM was carried out by a free-radical initiating process using ceric ammonium nitrate as an initiator. The evidence of the grafting reaction was examined by chemical analysis using Fourier transform IR spectroscopy. The grafting condition was standardized by regulating the reaction parameters such as the concentrations of the backbone, the monomer and the initiator, the polymerization temperature and time. The optimum polymerization temperature and time to have the maximum grafting yield were 40 °C and 3 h, respectively. The percentage of grafting and the percentage of grafting efficiency were determined as a function of the reaction parameters, and both were found to increasing initially and thereafter decrease in most of the cases. The grafting results are discussed in a detailed fashion and a reaction mechanism is proposed.     

Experimental design and the optimization of a polymer supported palladium complex for use in the Heck reaction

Optimization of the Heck reaction of 4-bromoacetophenone with styrene by a polymer supported, sulfur-containing palladacycle, varying 6 factors at a total of 28 different levels, corresponding to 5760 different possibilities was undertaken. Conversion improved from 34%, with large observable leaching to 88% with no leaching. This was accomplished using a Design of Experiments approach facilitated by the Statistical Design Package, MODDE 7.0^TM.     

To what extent can an uncertainty calculation be general?

 It is argued that results of uncertainty calculations in chemical analysis should be taken into consideration with some caution owing to their limited generality. The issue of the uncertainty in uncertainty estimation is discussed in two aspects. The first is due to the differences between procedure-oriented and result-oriented uncertainty assessments, and the second is due to the differences between the theoretical calculation of uncertainty and its quantication using the validation (experimental) data. It is shown that the uncertainty calculation for instrumental analytical methods using a regression calibration curve is result-oriented and meaningful only until the next calibration. A scheme for evaluation of the uncertainty in uncertainty calculation by statistical analysis of experimental data is given and illustrated with examples from the author's practice. Some recommendations for the design of corresponding experiments are formulated.     

毛细管电泳柱端安培检测装置的研制

研制了一种新型的毛细管电泳柱端型安培检测装置。以直径为6μm的碳纤维微电极为工作电极,在自组装的ACS-2000毛细管电泳仪上,考察了用不同内径毛细管分离时分离电压对背景噪声的影响。利用该装置同时测定了3种苯二酚的异构体。     

基于过程分析技术和设计空间的金银花醇沉加醇过程终点检测

建立了一种新的基于过程分析技术(PAT)和质量源于设计(QbD)设计空间的中药制药过程终点分析与控制方法.以近红外(NIR)光谱技术为PAT工具, 采集正常操作条件下制药过程的多批次NIR光谱; 采用主成分分析结合移动块相对标准偏差(PCA-MBRSD)法, 确定每一批次过程的理想终点样本(DEPs), 由多批DEPs的光谱信息构成过程终点设计空间; 在过程终点设计空间确定的范围内, 建立多变量统计过程控制(MSPC)模型, 利用多变量Hotelling T²和SPE控制图对过程终点进行判断.应用上述方法, 进行了金银花醇沉加醇过程终点检测研究, 结果表明该方法灵敏、准确, 适宜于中药制药过程终点检测.     

电光高分子材料的最新研究进展

电光高分子材料由于其在光电子信息领域的潜在应用前景已得到了广泛关注和深入研究.本文在简要介绍电光效应及其材料等相关知识的基础上,综述了最近几年来电光高分子材料的研究进展,主要包括生色团的设计与合成,以及掺杂型、侧链型、主链型、交联型、互穿网络型和树枝型等聚合物材料体系的设计与合成.     

Application of Task-specific Ionic Liquids for Intensified Separations

Summary. Ionic liquids offer tremendous opportunities to intensify reactions and separations in process technologies by tuning their physical and chemical properties. Several ionic liquids are suitable for the separation of aromatic and aliphatic hydrocarbons. CO₂ absorption behavior was influenced by the functionalized chains appended to the room temperature ionic liquid (RTIL) cation. Ionic liquids seem able to combine the chemical features of amine solutions with the characteristic advantages of the physical solvents used for CO₂ absorption.