酶催化区域选择性合成蔗糖酯的研究进展

详细综述了非水相酶催化合成蔗糖酯的研究进展。主要介绍了酶的种类、反应介质、底物性质、外加辅助手段等因素对蔗糖酯产率以及对酶区域选择性的影响。酶催化区域选择性合成蔗糖酯的难点在于蔗糖具有多个可酰化羟基及其与酰基供体的不相溶性,提出通过介质工程、底物修饰改性、外加物理场如微波和超声波辅助等改善底物相溶性,通过筛选酶、蔗糖修饰等可以得到高区域选择性的蔗糖酯。最后指出酶催化合成蔗糖酯存在的问题、发展前景等。     

蔗糖酯的酶促合成研究进展

蔗糖酯是通过脂肪酸类化合物和蔗糖合成的一种重要食品添加剂。相对于化学催化,酶催化条件温和,操作简单,更具有高的选择性。就蔗糖酯不同位置上的选择性酶促合成进展做一综述.     

酶催化合成糖脂肪酸酯研究进展

侧重介绍了在不同体系中酶催化糖酯合成的研究进展,其中包括微乳化法,有机溶剂法,糖基修饰法,酶修饰法,无溶剂法,固定化法。     

酶催化合成混合型蔗糖酯的研究

脂肪酸蔗糖酯是一种非离子表面活性剂，可用于日用化工、食品工业、医药行业等方面。过去多以碱性物质为催化剂，在较高温度由脂肪酸和蔗糖合成。由于脂肪酸及蔗糖在较高温度下不稳定，导致脂肪酸蔗糖酯产率降低，产品质量低下。近年来，利用脂肪酶为催化剂在较低温度下催化合成脂肪酸蔗糖酯的研究引起了人们的兴趣。     

酶催化选择性脱酰作用在糖酯合成中的应用研究进展

较详细地综述了目前国外酶催化选择性脱酰合成糖酯的研究进展,并对酶的主要来源和选择性脱酰的位置等进行了介绍,认为酶催化选择性脱酰技术在糖酯合成中有重要的应用价值,具有方法简便,产率较高等特点,该方法的运用扩展了糖酯类物质合成的空间。     

相转移催化合成蔗糖硬脂酸酯

采用相转移催化的基本原理和方法合成蔗糖硬脂酸酯,考察了反应时间、反应温度、原料的不同配比和催化剂用量对蔗糖硬脂酸酯产率的影响,得出反应时间为3 h,反应温度为95-100℃、硬脂酸甲酯与蔗糖的摩尔比为1:2.5,硬脂酸甲酯与PTC之比为1:0.07时为最佳配比。     

相转移催化合成蔗糖油酸酯

以蔗糖和油酸酯为原料应用相转移催化剂(PTC)与碱性催化剂结合，合成蔗糖油酸酯，考察了反应时间、反应温度和催化剂用量对蔗糖油酸酯产率的影响，得出反应时间为4h，反应温度为100℃～110℃、催化剂聚乙二醇400(PEG-400)为油酸甲酯摩尔数的8％～10％，蔗糖油酸酯的产率达80％以上，单酯质量分数可以达到50％。     

蔗糖酯的合成与应用研究进展

蔗糖酯是一种性能优良的非离子表面活性剂,综述了蔗糖酯的合成方法,分别了溶剂法（包括二甲基甲酰胺法、丙二醇法、水溶剂法、甲醇法及相转移催化法）及非溶剂法（包括生物合成法）。对蔗糖酯的应用及市场情况作了较为详细的介绍。     

硫酸氢钠催化合成丁酸酯

硫酸氢钠能够代替硫酸作为酯化催化剂，讨论了利用一水硫酸氢钠为催化剂时，丁酸与各种醇的酯化作用。研究了催化剂的重复使用性能。结果表明，硫酸氢钠对于酯化作用具有活性反应温和、无腐蚀及无废酸等优点。     

The synthesis of sucrose esters from telomer monocarboxylic acids

Glycolipid biosurfactants possess excellent surfactant properties and can be useful model compounds for the synthesis of surfactants from materials available in large quantities. The incorporation of a long, branched alkyl group, which is a feature of glycolipids, into a synthetic surfactant was achieved by the transesterification of sucrose with the methyl ester of a selected telomer monocarboxylic acid mixture, in a solution reaction. Characterisation showed the product to be a mixture of mono- and diesters each comprising a different ratio of linear to branched alkyl chains in the substituted group. Surfactant properties of the mixture, and the chromatographically-separated components, when evaluated in both distilled water and a salt solution, were found to be superior to a range of sucrose stearates. In addition the biosurfactant analogues were found to be more effective than surfactants derived from β-keto alkyl esters of various sugars (including sucrose) but were not as efficient as these latter compounds.     

Application of lipases to the regioselective synthesis of sucrose fatty acid monoesters

A regioselective synthesis of 6′-O-acyl sucrose monoesters has been developed through the lipase-catalyzed esterification of sucrose acetals with fatty acids in both organic solvents and under solvent-free conditions. The products were obtained in overall yields of 20–27% after hydrolysis of the isopropylidene groups with aqueous acids. The strict selectivity of the enzymes used also enabled the preparation of a monoester fraction that was highly enriched in 6-O-acyl sucrose. This was accomplished by lipase-catalyzed transesterification of sucrose monoesters, prepared by conventional chemical methods, in propan-2-ol. After removal of the transesterification products (sucrose and fatty acid isopropyl esters) and column chromatography on silica gel, the obtained monoester product contained 80% of the single regioisomer, 6-O-acyl sucrose.     

Enzyme‐catalyzed regioselective synthesis of sucrose‐based esters

Sucrose‐based esters are nonionic biosurfactants, which can be synthesized from the enzyme‐catalyzed esterification/transesterification of sucrose. The multi‐hydroxyl groups of sucrose and the immiscibility of sucrose with the acyl donors are the main bottlenecks in obtaining highly regioselective sucrose‐based esters. In this mini‐review, the effects of reaction conditions such as biocatalysts, design of solvent systems used as reaction media, modification and denaturation of substrates, and coupling with external auxiliary physical fields such as microwave irradiation and ultrasonic waves on the yield of sucrose esters and regioselectivity of products are highlighted. The existing problems in the field of enzymatic synthesis of sucrose esters as well as its future perspectives were pointed out. Copyright © 2011 Society of Chemical Industry     

有机相酶法合成己二酸单乙烯蔗糖酯的研究

以蔗糖和己二酸二乙烯酯(DVA)为原料,采用单因素法和均匀设计法对脂肪酶Novozym-435在有机溶剂中选择性地催化合成己二酸单乙烯蔗糖酯进行了研究。考察了有机溶剂种类及含水量、反应温度、酶质量浓度、底物摩尔比对产物产率的影响,得到蔗糖单(己二酸单乙烯酯)酯(SMVA)、蔗糖双(己二酸单乙烯酯)酯(SDVA)的适宜合成条件及相应的产率分别为:在叔丁醇介质中,不含水,反应温度49℃,酶质量浓度30 mg/mL,糖酯摩尔比1∶3.2的条件下,反应4 d,SMVA的产率为13.69%;在丙酮介质中,不含水,反应温度47.5℃,酶质量浓度30 mg/mL,糖酯摩尔比1∶3.3的条件下,反应3 d SDVA的产率为28.82%。用FTIR、HPLC、HPLC-MS和TLC等对产物SMVA、SDVA等进行了表征。     

研磨强化无溶剂法合成蔗糖脂肪酸酯

以蔗糖和脂肪酸甲酯为反应原料,无溶剂条件下采用研磨强化的方法合成了蔗糖脂肪酸酯(即蔗糖酯),考察了研磨时间、乳化剂用量、反应时间、反应压力以及催化剂用量对蔗糖酯收率及脂肪酸甲酯转化率的影响,产品经水洗、醇提精制后,用FTIR和HPLC-ELSD对其进行了表征和分析。结果表明:研磨处理能将反应分散物粒径(D50)降至约5μm,有效地增强了蔗糖与脂肪酸甲酯的无溶剂酯交换反应。得到的最优反应条件为:研磨时间为60min,硬脂酸钾乳化剂质量分数为10%(占体系总质量,下同),K2CO3质量分数为2.0%,反应时间6 h,反应压力0.5 kPa,在该条件下脂肪酸甲酯转化率为91.2%,蔗糖酯收率为61.6%。精制后产品中蔗糖酯质量分数为81.9%,且其游离糖质量分数为0.6%,酸值为3.0mgKOH/g,水分(质量分数)为0.2%和灰分(质量分数)为0.5%,均达到FAO/WHO标准。     

Enzyme‐catalyzed regioselective synthesis of sugar esters and related compounds

In this review, a comprehensive and illustrative survey is made of the regioselective synthesis of esters of sugars and related compounds using lipases. The main emphasis has been given to the screening and use of commercially available lipases for the enzymatic esterification of neutral monosaccharides, disaccharides, sugar alcohols and their selected ether and ester derivatives. The effect of solvents and solubilizing agents in improving the yields of the resultant sugar fatty acid esters has been incorporated. Further, solvent‐free esterification with molten fatty acids, use of ionic liquids and microwave radiations for improvement in the methodology have also been discussed. Copyright © 2006 Society of Chemical Industry     

表面活性剂蔗糖酯在药物递送系统的应用

蔗糖酯（Sucrose esters，SEs）是一种被广泛使用在食品、化妆品工业中的表面活性剂。近年来，SEs由于其良好的生物降解性、乳化和增溶作用，在医药领域的应用是其应用的一个巨大突破，引起了国内外研究者的极大兴趣。SEs在药物控制释放体系中，能促进药物的溶解、药物的吸收或渗透，从而提高药物的治疗效果。目前，关于蔗糖酯在药物递送领域的应用还没有综述文献的报道，本文在近年来SEs用于药物递送研究的基础上，介绍了SEs的主要特性、其在生物医药领域的应用，着重讨论和总结了SEs在药物递送领域的一些应用，以及SEs的毒理学研究现状。展望了SEs在医药领域的发展前景，并提出SEs在该领域还需深入研究的问题，为SEs在医药领域的深入研究提供理论参考。     

高单酯含量蔗糖酯的无溶剂制备

通过把微细蔗糖和硬脂酸甲酯制成粗分散体系(粒径小于10μm),用无溶剂法制备出了单酯含量高达79.8%的蔗糖酯。与其他典型的方法不同,该方法仅用4%的皂就可使硬脂酸甲酯转化率超过99%,大大减少了皂的用量。而且用相同量的皂就可制备出不同单酯含量的蔗糖酯,产率最高可达62.4%。考察了这种新反应体系的温度、催化剂量、皂的量和反应时间等不同条件下硬脂酸甲酯的转化率,还测定了不同单酯含量蔗糖酯的亲水亲油平衡(HLB)值、表面张力、界面张力和临界胶束浓度,揭示了它们之间的相互关系。