Natural products from Bacillus subtilis with antimicrobial properties☆

Bacil us subtilis produces many chemical y-diverse secondary metabolites of interest to chemists and biologists. Based on this, this review gives a detalled overview of the natural components produced by B. subtilis including cyclic lipopeptides, polypeptides, proteins (enzymes), and non-peptide products. Their structures, bioactive ac-tivities and the relevant variants as novel lead structures for drug discovery are also described. The challenging effects of fermentation metabolites, isolation and purification, as wel as the overproduction of bioactive com-pounds from B. subtilis by metabolic engineering, were also highlighted. Systematical y exploring biosynthetic routes and the functions of secondary metabolites from B. subtilis may not only be beneficial in improving yields of the products, but also in helping them to be used in food industry and public medical service on a large-scale.     

Membrane materials in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures—A review

The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry,but challenged in some cases.Compared with conventional separation technologies,pervaporation is quite promising in terms of its economical,energy-saving,and eco-ffiendly advantages.However,this technique has not been used in industry for separating aromatic/aliphatic mixtures yet.One of the main reasons is that the separation performance of existed pervaporation membranes is unsatisfactory.Membrane material is an important factor that affects the separation performance.This review provides an overview on the advances in studying membrane materials for the pervaporation separation of aromatic/aliphatic mixtures over the past decade.Explored pristine polymers and their hybrid materials (as hybrid membranes) are summarized to highlight their nature and separation performance.We anticipate that this review could provide some guidance in the development of new materials for the aromatic/aliphatic pervaporation separation.     

ELECTROSTATIC PSEUDO LIQUID MEMBRANE SEPARATION TECHNOLOGY

Electrostatic pseudo liquid membrane(ESPLIM)separation process,developed recently in this laboratory,is a novel chemical separation technology.ESPLIM is an interdisciplinary technology evolved from thecombination of solvent extraction,liquid membrane and electrostatic techniques.It can be used to separate,purify and concentrate specific solutes from aqueous solutions.Therefore,it is suitable for the recovery ofvaluable metals from aqueous solutions in the field of hydrometallurgy(including nuclear fuel cycles)and forthe processes of waste water treatment.This paper discusses the basic principles of this new technology.Taking the extraction of Co~(2+)by D2EHPA as an example,effects on metal extraction of electrical fieldstrength,extractant concentration and the flow ratio of feed to stripping solution have been studied.Exper-iments show that the once through extraction efficiency of Co~(2+)can reach 99% while Co~(2+)can be concen-trated up to 40—50g/L in the stripping solution.     

混合分离过程的有序设计框架

The design of optimal separation flow sheets for multi-component mixtures is still not a solved problem This is especially the case when non-ideal or azeotropic mixtures or hybrid separation processes are considered. We review recent developments in this field and present a systematic framework for the design of separation flow sheets. This framework proposes a three-step approach. In the first step different flow sheets are generated. In the second step these alternative flow sheet structures are evaluated with shortcut methods. In the third step a rigorous mixed-integer nonlinear programming （MINLP） optimization of the entire flow sheet is executed to determine the best alternative. Since a number of alternative flow sheets have already been eliminated, only a few optimization runs are necessary in this final step. The whole framework thus allows the systematic generation and evaluation of separation processes and is illustrated with the case study of the separation of ethanol and water.     

SIMULATION OF DISTILLATION PROCESSES WITH REACTIONS IN SERIES

This paper introduces a mathematical model and advances an algorithm,that can be used for simu-lation of reactive distillation processes.This model takes into account the reactions in series,that occurwithin a distillation column and this algorithm is based upon the block tridiagonal matrix technique.In order to accomplish a computation of design and inspect whether or not different configuration of flowsbetween stages can increase the yields of intermediate products,a procedure for solving block tridiagonalmatrix equation with some off-tridiagonal submatrixes and/or submatrixes on the borders is modified.The saponification of propylene chlorophydrin is illustrated to verify the algorithm.It can be seen thatthe results are satisfactory.     

First Continuous Natural Gutta-percha Device Built in China

正The first set of 100-ton continuous natural gutta-precha production device was recently completed and put into operation in Hunan Xiangxi Laodie Bio-technoIogy Co.,Ltd.This marked that Chinese natural gutta-percha extraction had climbed to a new level and it would accumulate valuable experience and lay a good foundation for the scale developmeat of national natural gatta-percha,said the expert group of Eucommia Ulmoides Industry Alliance.     

An efficient methodology for utilization of K-feldspar and phosphogypsum with reduced energy consumption and CO2 emissions

The issues of reducing CO2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO2 with reduced CO2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the high-temperature co-reaction significantly facilitated the reduction of phosphogypsum to SO2 and the exchange of K+(K-feldspar) with Ca2+(CaSO4 in phosphogypsum). The reaction parameters were systematical y investigat-ed with the highest sulfur recovery ratio of~60%and K extraction ratio of~87.7%. This novel methodology possesses an energy consumption reduction of~28%and CO2 emission reduction of~55%comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.     

A FUZZY MATCH BASED EXPERT SYSTEM FOR SYNTHESIS OF SEPARATION PROCESSES

A predictive parallel search algorithm,the fuzzy match inference strategy,is implemented ina prototype expert system.Selection of separation technologies and sequencing of separators are beingapproached in an integrated manner.The fuzzy match mechanism results in a relatively smaller subsetof favored schemes,constituting a hyperstructure for further quantitative evaluation and combinationoptimization.An industrial application example of aromatics extraction separation is presented.     

Bovine Placental Bioactive Proteins Preparation and Efficacy Evaluation

Taking the qualiffed bovine placenta as the research object, a series of pure physical separation and extraction processes such as tissue fragmentation, ultrasound, freeze-thawed, centrifugation and filtration were used to prepare the bovine placental bioactive proteins. The results of protein concentration showed that bovine placental bioactive proteins prepared in this study could reach(11.33 ± 2.09) mg/mL under optimal experimental condition. The determination of speciffc components showed th...     

Determination of Teicoplanin A2's Partition Coefficient in Different Liquid-Liquid Extraction Systems

Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partition coefficients and extraction ratio of teicoplanin in three different solvent systems were studied: conventional extraction, reactive extraction and reverse micelle extraction. With conventional solvent extraction, n-butanol demonstrated high partition coefficient for teicoplanin, but low extraction ratio because of its high solubility in water. Reactive extraction of teicoplanin showed the highest partition coefficient with almost 100% recovery in organic phase when tri-n-octylmethyl ammonium chloride (TOMAC) was used as extractant and pH value was above 5.0. A reverse micelle system, consisted of isooctane 10mmol-L-1 TOMAC 1% n-octanol, also offered high separation factor for teicoplanin. The results are beneficial for the design of teicoplanin separation and purification process.     

Bioactive compounds and advanced processing technology: Phaleria macrocarpa (sheff.) Boerl,a review

Recent technological advances and the development of new methods has provided an opportunity to obtain highly purified natural bioactive compound extracts with potential for the treatment and prevention of human diseases. The use of hazardous and toxic solvents for the extraction and processing of bioactive compounds from plant materials is considered a problem for health, safety and environmental pollution. Advanced technology aims to increase production of the desired compounds and find an alternative to using toxic solvents in the extraction of bioactive compounds from plant materials. The ever growing interest in plant bioactive compounds and today's concerns about environment issues have led to an increased need for an efficient and green extraction method. This review is focused on the extraction of bioactive compounds from plants using advanced and environment‐friendly methods such as supercritical fluid extraction, microwave‐assisted extraction, ultrasound‐assisted extraction and similar techniques that can extract rapidly and free from organic residues. An updated overview of the bioactive compounds present in the plant Phaleria macrocarpa and its extraction, fractionation, purification and isolation is provided. The advantages and disadvantages of both conventional and non‐conventional extraction methods are also discussed in this review. © 2014 Society of Chemical Industry     

现代分离技术在磷脂酰胆碱分离纯化中的应用

磷脂酰胆碱是一种重要的生物活性物质,在食品、保健品、医药、化妆品等行业得到广泛应用。本文综述了超声波萃取法、微波萃取法、高压脉冲法、树脂吸附法、溶剂冷冻法等新技术在磷脂酰胆碱分离纯化研究方面的进展。     

新技术在天然产物分离中的应用进展

超临界CO2萃取、分子蒸馏技术是近年来倍受关注的高新分离技术,本文简述了他们的基本原理、技术特点以及在天然产物领域中的应用现状,并探讨了超临界、分子蒸馏联用技术提取分离天然有效成分的可行性及在工业化应用中存在的问题,以期为该领域的生产和研究工作提供参考。     

手性萃取剂与液-液萃取拆分对映体技术研究进展

手性对映体的拆分是当前备受关注的一个研究领域。手性对映体的拆分方法有多种, 手性液-液萃取拆分法是其中有较好发展前景的一种手性对映体拆分技术。本文概述了手性液-液萃取技术的基本原理, 并进一步对酒石酸类手性萃取剂、环糊精类手性萃取剂、冠醚类手性萃取剂、金属络合物类手性萃取剂等不同种类手性萃取剂及其研究进展进行了综述。分析表明, 手性液-液萃取拆分技术对外消旋体特别是药物外消旋体的拆分有较好的效果, 随着对手性萃取剂研究的进一步深入, 手性液-液萃取有望成为一种手性化合物拆分的重要方式。     

天然产物样品的高通量制备技术

自动化制备高质量和足够数量的样品是进行高通量筛选天然产物的前提 ,是发现新生物活性分子的关键步骤之一。通过基于固相萃取或高效液相 /固相萃取联用的自动化方法制备天然产物样品 ,制得的样品质量和数量能够满足高通量筛选天然产物的需要。     

近年国内高速逆流色谱分离天然产物的应用

高速逆流色谱(HSCCC)是一种快速高效的分离方法。综述了近五年来关于HSCCC分离天然产物的研究进展,详细的论述了常用溶剂体系适合分离物质的特征,列举了大量的应用实例和被分离物质的结构及分配系数,对其分离提取天然产物有效成分的应用及其进展进行了综述,对快速选择溶剂体系起到了一定的指导作用。并对HSCCC的未来发展进行展望。     

现代分离技术在何首乌成分分离中的应用

文章对何首乌成分分离中常用的技术方法进行了综述,分别介绍了经典柱色谱、超临界流体萃取、微波提取、高速逆流色谱等技术及其在何首乌成分分离中的应用,为何首乌成分的提取分离提供了参考。     

SFE-MD联用技术在天然产物分离提纯中的应用进展

分子蒸馏技术与超临界萃取技术都是新型的绿色分离技术,二者联用技术也一直备受各国关注。本文介绍了超临界萃取（SFE）与分子蒸馏（MD）技术的原理特点,综合评述了SFE-MD联用技术在天然产物分离提纯中的发展概况及其应用特点,并对该技术在天然产物提纯方面的前景进行了展望。     

天然有机物提取及表征技术近期发展动态

在阐述天然有机物(NOM)来源和危害的基础上,对NOM的提取、分离和表征技术的近期发展动态进行了全面综述。介绍了NOM的各种提取和分离方法,对各种提取方法的优缺点和产率进行了分析比较,指出以反渗透、大孔树脂和膜分离为核心的工艺为目前最主要的提取分离手段。此外,详细列举了包括光谱、色谱、核磁共振、原子力显微成像等在内的NOM表征方法,对各分析结果所对应的NOM的结构特征和物化性质进行了阐述。     

High-Performance Polymers for Separation and Purification Processes: An Overview

Separation and purification techniques are applied in many important fields, such as in the medical, chemical, metallurgical, environmental, and pharmaceutical industries. Recent advances in separation science and the urgent need for highly selective purification have necessitated a rapid progress with respect to the reagents, chemicals, and surfactants used in separation processes to attain a high efficiency and selectivity. Polymeric materials have attracted considerable interest, and they have been widely used as extractants, catalysts, and modifiers, in separation and purification processes. This review outlines the recent advances in the use of novel polymers, natural and synthetic, in different separation and purification techniques. Various separation techniques such as chromatography, crystallization, precipitation, distillation, electrophoresis, filtration, and mineral processing methods are discussed, and the polymers used in each method are described in terms of their properties, structure, and function. The application of polymers shows great promise in achieving a highly efficient separation, especially in the areas of membrane separation and water purification. The rational design of new multifunctional polymers with triggered functions presumably presents new opportunities for the development of advanced separation methods.