无溶剂体系酶催化合成富含共轭亚油酸甘油脂的研究

采用中心组合设计和响应面方法 ,研究了无溶剂体系中脂肪酶催化共轭亚油酸(CLA)与油脂反应的主要影响因素。建立了二级响应面模型 ,模型的复相关系数为0 90。甘油酯中CLA含量随温度、反应时间、底物配比增加而提高 ,反应时间影响最为显著。水分含量对酸解反应具有负影响 ,反应温度及反应时间与水分含量有交互作用。优化的反应条件为 :反应时间 8～ 10h ,温度 4 0～ 4 5℃ ,酶量 2 0 0U / g油脂 ,底物配比 1:2 5 ,水含量 1 0 %。在优化条件下 ,红花油中共轭亚油酸含量可达 31 4 7%。脂肪酶催化 10 ,12 十八碳二烯酸反应优于 9,11 十八碳二烯酸。

Characterization of a novel marine microbial esterase and its use to make D-methyl lactate

A novel marine microbial esterase PHE14 was cloned from the genome of Pseudomonas oryzihabit‐ans HUP022 isolated from the deep sea of the western Pacific Ocean. Esterase PHE14 exhibited very good tolerance to most organic solvents, surfactants and metal ions tested, thus making it a good esterase candidate for organic synthesis that requires an organic solvent, surfactants or metal ions. Esterase PHE14 was utilized as a biocatalyst in the asymmetric synthesis of D‐methyl lactate by enzymatic kinetic resolution. D‐methyl lactate is a key chiral chemical. Contrary to some previous reports, the addition of an organic solvent and surfactants in the enzymatic reaction did not have a beneficial effect on the kinetic resolution catalyzed by esterase PHE14. Our study is the first report on the preparation of the enantiomerically enriched product D‐methyl lactate by enzymatic kinetic resolution. The desired enantiomerically enriched product D‐methyl lactate was obtained with a high enantiomeric excess of 99%and yield of 88.7%after process optimization. The deep sea mi‐crobial esterase PHE14 is a green biocatalyst with very good potential in asymmetric synthesis in industry and can replace the traditional organic synthesis that causes pollution to the environment.

Catalytic Pyrolysis of Biodiesel Surrogate over HZSM-5 Zeolite Catalyst

To obtain insight into the catalytic reaction mechanism of biodiesels over ZSM-5 zeolites,the pyrolysis and catalytic pyrolysis of methyl butanoate,a biodiesel surrogate,with H-type ZSM-5(HZSM-5)were performed in a flow rereac tor under atmospheric pressure.The pyrolysis products were identified and quantified using gas chroma to graphy-mass spec trome try(GC-MS).Kine tic modelling and experimental results revealed that H-atom abstraction in the gas phase was the primary pathway for methyl butanoate decomposition during pyrolysis,but dissociating to ketene and methanol over HZSM-5 was the primary pathway for methyl butanoate consumption during catalytic pyrolysis.The initial decomposition temperature of methyl butanoate was reduced by approximately 300 K over HZSM-5 compared to that for the uncatalyzed reaction.In addition,the apparent activation energies of methyl butanoate under catalytic pyrolysis and homogeneous pyrolysis conditions were obtained using the Arrhenius equation.The significantly reduced apparent activation energy confirmed the catalytic performance of HZSM-5 for methyl but anoa te pyrolysis.The act iva tion t empera ture may also affec t some catalytic proper ties of HZSM-5.Overall,this study can be used to guide subsequent catalytic combustion for practical biodiesel fuels.

酸增殖剂及其应用

基于自催化酸解反应的酸增殖是新的提高成像灵敏度的方法。目前发现有实用价值的酸增殖剂绝大多数为磺酸酯类化合物。本文详细介绍了酸增殖机理和酸增殖剂的种类,比较了2-甲基-2-(对甲苯磺酰氧甲基)-3-酮-丁酸叔丁酯、环己二醇二甲苯磺酸酯、三聚羟基丙醛三对甲苯磺酸酯在化学增幅抗蚀剂体系中的应用性能,认为环己二醇二碳酸酯的灵敏度高,更具有实用价值。