酸化油固定床酶法合成生物柴油研究

以固定化的假丝酵母酶为催化剂，在三段式固定床反应器内，醇油摩尔比为1：1，采用分级流加甲醇的方式，将高酸值的酸化油转化为生物柴油，探讨了酶量、溶剂量、水量、温度、反应液流速等与产物中甲酯含量的关系。正交实验结果表明，反应的最适条件为酶用量、溶剂量、水量分别为油重的15％、10％、10％，反应液流速为0.8g·min^-1，温度为45℃，在此条件下，产物中甲酯含量达到了90．18％。     

反胶束中脂肪酶CSL催化性能的研究

以葵花籽油为底物，考察了未见报道的国产脂肪酶ＣＳＬ在ＡＯＴ／异辛烷反胶束体系中的催化性能，当底物体积分数为１０％，ＰＨ＝８．０，Ｔ＝３１３Ｋ，水与表活性剂的浓度比Ｗ０＝１２时，脂肪酶的催化活力最高；而且，当底物体积分数为２０％时，仍未发生抑制现象。     

脂肪酶基因结构和氨基酸序列的比较

采用PCGENE6 8软件系统对真菌脂肪酶基因和氨基酸序列进行了分析。真核生物中多数结构基因中含有内含子 ,但真菌脂肪酶基因几乎有一大半的是连续的 ;对于有内含子的基因 ,不同脂肪酶基因所含内含子数目各异。所有脂肪酶一级结构中都包含Gly X1 Ser X2 Gly保守序列 ,在真菌脂肪酶中该序列更保守 ;Ser、Asp/Glu和His3个氨基酸残基组成了真菌脂肪酶的活性中心 ;大多数真菌脂肪酶是糖蛋白 ,但也有一些不含糖基的脂肪酶 ,主要取决于脂肪酶一级结构中是否存在糖基化识别序列。     

The most favorable condition for lipid hydrolysis by Rhizopus delemar lipase in combination with a sugar–ester and alcohol W/O microemulsion system

The hydrophobic interfacial characterization of sugar–ester alcohol W/O microemulsion was investigated in order to develop a suitable design for reaction media. A W/O microemulsion system was prepared as a combination of sugar–ester, DK-ester-F-110 with alcohol as a cosolvent. The diameter of the sub-micron-sized water pool, the hydrophobicity of the water pool, and the fluidity of the micro-interface were studied to analyze the reactivity of Rhizopus delemar lipase in lipid hydrolysis. The diameter of the sub-micron sized water pool was measured by dynamic laser light scattering. It was proportional to the 0.33 power of W_soln and decayed with increasing alcohol concentration. The initial reaction rate of the hydrolysis of triolein in W/O microemulsion depended on the solubilized water content. The hydrophilic character of the micro-water pool was estimated from the fluorescence wavelength indicated by Coumarin 343. The maximum initial reaction rate appeared at 450–460 nm. The fluidity of the micro-interface was investigated by fluorescence anisotropy using TMA-DPH. A suitable physicochemical reaction condition for high reactivity to occur was found, satisfying both the hydrophilicity and the fluidity of the micro-interface.     

抗大鼠肝脏脂酶抗血清的制备及应用

按照ＲＨＬｃＤＮＡ核苷酸序列所预示肽链的氨基酸序列，化学合成了与肽链Ｎ端、Ｃｕｍｄｊｔ ｋ ｕｋ ｓｈ ｃｆ ｙｉｄ ｒ ３ｗｈ ｅｅｄｙ     

Lipase-Catalyzed Synthesis of Carboxylic Amides: Nitrogen Nucleophiles as Acyl Acceptor

Summary.  The lipase-catalyzed aminolysis of carboxylic esters is a fairly general reaction that has been performed with a wide range of esters and amines, generally in anhydrous organic media to avoid undesirable hydrolysis of the ester. Alternatively, carboxylic amides can be synthesized by lipase mediated condensation of carboxylic acids and amines if an excess of either reactant is avoided. Chiral carboxylic esters have been resolved by lipase-catalyzed aminolysis. In the majority of these resolutions, Candida antarctica lipase B has been employed as the catalyst. A range of chiral amines has been resolved by lipase mediated acylation, using mainly the lipases from C. antarctica (B type) and Pseudomonas species. The enantiorecognition was frequently found to depend critically on the acylating agent and the reaction medium. Received December 20, 1999. Accepted January 1, 2000     

蚯蚓冻干粉对高血脂小鼠胆固醇逆转运相关基因的调节作用

以高脂饲料饲喂昆明种小鼠构建高血脂小鼠模型,灌胃给予高、中、低剂量(0.4,0.2,0.1g/kg)蚯蚓冻干粉,每天1次,同时饲喂高脂饲料,以仅饲喂高脂饲料组小鼠为对照,共饲养10周.提取小鼠肝脏总RNA,应用半定量RT-PCR技术检测实验组与对照组小鼠胆固醇逆转运相关基因卵磷脂胆固醇酰基转移酶(lecithin cholesterol acyltransferase,LCAT)和脂蛋白酯酶(lipoprotein lipase,LPL)mRNA表达水平.结果表明,蚯蚓冻干粉极显著提高实验组小鼠LCAT mRNA表达水平(P0.01),显著提高LPL mRNA表达水平(P0.05),提示这是蚯蚓冻干粉能够降低高血脂小鼠血浆胆固醇水平的原因之一.     

Indoline-3-carboxylic acid derived organocatalysts for the anti-Mannich reaction

Mannich type reactions of a preformed aldimine with various carbonyl compounds were investigated with a series of functionalised indoline derivatives as catalysts: indoline‐3‐carboxylic acid, the diphenylcarbinol analogue and O‐protected silyl ether analogues. All compounds were readily prepared in enantiopure form by using an enzymatic kinetic resolution as a key step (E?100). The alcohol and ether catalysts failed to induce complete chirality transfer but did afford the Mannich bases in good yields and high diastereomeric ratios, whereas the acid catalyst gave the products in a highly diastereo‐ and enantioselective manner. The absolute configuration of the products was determined by a syn–anti isomerisation protocol, initiated by the sterically demanding base 1,8‐diazabicyclo[5.4.0]undec‐7‐ene.     

酶促制备丝裂霉素类似物反应动力学模型研究

基于固定化T. laibacchii脂肪酶催化2-甲基-1,4-苯醌与正丁胺的Michael加成反应建立了酶促制备丝裂霉素类似物2-甲基-3-正丁胺酰-1-氢-4-醌的反应动力学模型.该反应在柠檬酸缓冲溶液(pH值为7.0)中进行,最终产率可达98%.该文提出了修正的有序双双和随机双双机理,采用King-Altman方法得到相关微分方程组以表示即时反应速率.通过联合解微分方程和最优化方法确定动力学模型参数,使用ode45程序解微分方程组,并运用Fmincon软件计算动力学常数.研究结果表明:模型拟合值与实验值的平均相对偏差为11.25%,且偏差服从关于y=0的轴对称分布.当固定化酶粒径为0.5 mm、搅拌转速为200 rpm时可以忽略内外扩散限制.该文建立的动力学模型为固定化酶固有动力学模型.