PREPARATION OF HETEROBIMETALLIC COMPLEXES BRIDGING WITH π，π－BOUND PHENYLCYCLOPENTADIENYL LIGAND AND X－RAY CRYSTAL STRUCTURE OF （TRICARBONYL－π－CHROMIUM）PHENYLCYCLOPENTADIENYLCOBALT DICARBONYL

ＰＲＥＰＡＲＡＴＩＯＮＯＦＨＥＴＥＲＯＢＩＭＥＴＡＬＬＩＣＣＯＭＰＬＥＸＥＳＢＲＩＤＧＩＮＧＷＩＴＨπ，π－ＢＯＵＮＤＰＨＥＮＹＬＣＹＣＬＯＰＥＮＴＡＤＩＥＮＹＬＬＩＧＡＮＤＡＮＤＸ－ＲＡＹＣＲＹＳＴＡＬＳＴＲＵＣＴＵＲＥＯＦ（ＴＲＩＣＡＲＢＯＮＹＬ...     

7，2＇－DIDESACETOXY AUSTROSPICATINE， A NEW TAXANOID FROM THE BARKS OF TAXUS WALLICHIANA ZUCC

７，２＇－ＤＩＤＥＳＡＣＥＴＯＸＹ　ＡＵＳＴＲＯＳＰＩＣＡＴＩＮＥ，　Ａ　ＮＥＷ　ＴＡＸＡＮＯＩＤ　ＦＲＯＭ　ＴＨＥ　ＢＡＲＫＳ　ＯＦ　ＴＡＸＵＳ　ＷＡＬＬＩＣＨＩＡＮＡ　ＺＵＣＣ７，２＇－ＤＩＤＥＳＡＣＥＴＯＸＹＡＵＳＴＲＯＳＰＩＣＡＴＩＮＥ，ＡＮ...     

STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES 13．THE ASYMMETRIC CYCLIZATION OF （＋）－SUBSTITUTED CYCLOPENTANODIAMINE WITH O－ARYL THIOPHOSPHOROCHLORIDATES

ＳＴＵＤＩＥＳＯＮＣＨＩＲＡＬＴＨＩＯＰＨＯＳＰＨＯＲＩＣＡＣＩＤＳＡＮＤＴＨＥＩＲＤＥＲＩＶＡＴＩＶＥＳ１３．ＴＨＥＡＳＹＭＭＥＴＲＩＣＣＹＣＬＩＺＡＴＩＯＮＯＦ（＋）－ＳＵＢＳＴＩＴＵＴＥＤＣＹＣＬＯＰＥＮＴＡＮＯＤＩＡＭＩＮＥＷＩＴＨＯ－ＡＲＹ...     

STUDY OF THE CHEMILUMINESCENCE AND FLUORESCENCE REACTIONS CATALYZED BY MIMETIC PEROXIDASE MN（II）－TETA

ＳＴＵＤＹ　ＯＦ　ＴＨＥ　ＣＨＥＭＩＬＵＭＩＮＥＳＣＥＮＣＥ　ＡＮＤ　ＦＬＵＯＲＥＳＣＥＮＣＥ　ＲＥＡＣＴＩＯＮＳ　ＣＡＴＡＬＹＺＥＤ　ＢＹ　ＭＩＭＥＴＩＣ　ＰＥＲＯＸＩＤＡＳＥ　ＭＮ（ＩＩ）－ＴＥＴＡＨｕｉＺｈｉＦＡＮ；ＹｕｎＸｉａｎｇＣＩ（Ｄｅｐ...     

MOLECULAR MECHANICAL AND QUANTUM CHEMICAL CALCULATION ON ACYLATION REACTIVITY FOR 1－（NITRO SUBSTITUTED ANILINO）－4－SUBSTITUTED－2，6－PIPERAZINEDIONES

ＭＯＬＥＣＵＬＡＲＭＥＣＨＡＮＩＣＡＬＡＮＤＱＵＡＮＴＵＭＣＨＥＭＩＣＡＬＣＡＬＣＵＬＡＴＩＯＮＯＮＡＣＹＬＡＴＩＯＮＲＥＡＣＴＩＶＩＴＹＦＯＲ１－（ＮＩＴＲＯＳＵＢＳＴＩＴＵＴＥＤＡＮＩＬＩＮＯ）－４－ＳＵＢＳＴＩＴＵＴＥＤ－２，６－ＰＩＰＥＲＡＺ...     

SYNTHESIS OF THERMOTROPIC LIQUID CRYSTAL AROMATIC COPOLYESTERS AND COPOLY （ESTER－AMIDE）S CONTAINING DI （ETHYLOXY－ETHER） AS THE SPACER

ＳＹＮＴＨＥＳＩＳ　ＯＦ　ＴＨＥＲＭＯＴＲＯＰＩＣ　ＬＩＱＵＩＤ　ＣＲＹＳＴＡＬ　ＡＲＯＭＡＴＩＣ　ＣＯＰＯＬＹＥＳＴＥＲＳ　ＡＮＤ　ＣＯＰＯＬＹ　（ＥＳＴＥＲ－ＡＭＩＤＥ）Ｓ　ＣＯＮＴＡＩＮＩＮＧ　ＤＩ　（ＥＴＨＹＬＯＸＹ－ＥＴＨＥＲ）　ＡＳ　ＴＨ...     

α－OXOKETENE CYCLIC DITHIOACETALS CHEMISTRY ──REACTION OF α，α－DIOXO（ESTER）KETENE CYCLIC DITHIOACETALS WITH BUTANONE

α－ＯＸＯＫＥＴＥＮＥＣＹＣＬＩＣＤＩＴＨＩＯＡＣＥＴＡＬＳＣＨＥＭＩＳＴＲＹ──ＲＥＡＣＴＩＯＮＯＦα，α－ＤＩＯＸＯ（ＥＳＴＥＲ）ＫＥＴＥＮＥＣＹＣＬＩＣＤＩＴＨＩＯＡＣＥＴＡＬＳＷＩＴＨＢＵＴＡＮＯＮＥ￥ＺａｉＭｉｎｇＺＨＵ；ＹｏｎｇＴｉｎｇＸ...     

THE INTRAMOLECULAR STACKING INTERACTION IN TERNARY COMPLEXES FORMED BY AND HETEROAROMATIC N－BASE LIGANDS

ＴＨＥ　ＩＮＴＲＡＭＯＬＥＣＵＬＡＲ　ＳＴＡＣＫＩＮＧ　ＩＮＴＥＲＡＣＴＩＯＮ　ＩＮ　ＴＥＲＮＡＲＹ　ＣＯＭＰＬＥＸＥＳ　ＦＯＲＭＥＤ　ＢＹ　ＡＮＤ　ＨＥＴＥＲＯＡＲＯＭＡＴＩＣ　Ｎ－ＢＡＳＥ　ＬＩＧＡＮＤＳＴＨＥＩＮＴＲＡＭＯＬＥＣＵＬＡＲＳＴＡＣ...     

STUDIES ON SEPARATION AND DETERMINATION OF THE COUMARINS IN MURRAYA PANICULATA（L）JACK BY RP－HPLC

ＳＴＵＤＩＥＳ　ＯＮ　ＳＥＰＡＲＡＴＩＯＮ　ＡＮＤ　ＤＥＴＥＲＭＩＮＡＴＩＯＮ　ＯＦ　ＴＨＥ　ＣＯＵＭＡＲＩＮＳ　ＩＮ　ＭＵＲＲＡＹＡ　ＰＡＮＩＣＵＬＡＴＡ（Ｌ）ＪＡＣＫ　ＢＹ　ＲＰ－ＨＰＬＣＳＴＵＤＩＥＳＯＮＳＥＰＡＲＡＴＩＯＮＡＮＤＤＥＴＥＲＭＩ...     

SYNTHESIS AND X－RAY STRUCTURE OF A NEW PYRRYL SUBSTITUTED PHOTOCHROMIC FULGIDE

ＳＹＮＴＨＥＳＩＳＡＮＤＸ－ＲＡＹＳＴＲＵＣＴＵＲＥＯＦＡＮＥＷＰＹＲＲＹＬＳＵＢＳＴＩＴＵＴＥＤＰＨＯＴＯＣＨＲＯＭＩＣＦＵＬＧＩＤＥＳＹＮＴＨＥＳＩＳＡＮＤＸ－ＲＡＹＳＴＲＵＣＴＵＲＥＯＦＡＮＥＷＰＹＲＲＹＬＳＵＢＳＴＩＴＵＴＥＤＰＨＯＴＯＣＨＲ...     

STUDY ON IMMOBILIZED PORCINE PANCREATIC LIPASE CATALYZING TRANSESTERIFICATION BETWEEN METHYL—BUTYRATE AND 1—BUTANOL IN NONAQUEOUS SYSTEMS

Transesterification between methyl-butyrate and 1-butanol in nonaqueous systems was catalyzed by porcine pancreatic lipase which was immobilized on cross-linked polystyrene.Organic solvents,substrate concentration,contents of water and other parameters which affect the immobilized enzyme activity were studied.Lipase immobilized on hydrophobic crosslinked polystyrene can reduce its diffusion limit in the reaction.It was found that the activity of immobilized lipase in organic systems was two times as high as that of free lipase.     

Immobilization and Properties of Lipase from Candida rugosa on Electrospun Nanofibrous Membranes with Biomimetic Phospholipid Moities

Reported here is a protocol to fabricate a biocatalyst with high enzyme loading and activity retention, from the conjugation of electrospun nanofibrous membrane having biomimetic phospholipid moiety and lipase. To improve the catalytic efficiency and activity of the immobilized enzyme, poly（acrylonitrile-co-2-methacryloyloxyethyl phosphorylcholine）s（PANCMPCs） were, respectively, electrospun into nanofibrous membranes with a mean diameter of 90 nm, as a support for enzyme immobilization. Lipase from Candida rugosa was immobilized on these nanofibrous membranes by adsorption. Properties of immobilized lipase on PANCMPC nanofibrous membranes were compared with those of the lipase immobilized on the polyacrylonitrile（PAN） nanofibrous and sheet membranes, respectively. Effective enzyme loading on the nanofibrous membranes was achieved up to 22.0 mg/g, which was over 10 times that on the sheet membrane. The activity retention of immobilized lipase increased from 56.4% to 76.8% with an increase in phospholipid moiety from 0 to 9.6%（molar fraction） in the nanofibrous membrane. Kinetic parameter Km was also determined for free and immobilized lipase. The Km value of the immobilized lipase on the nanofibrous membrane was obviously lower than that on the sheet membrane. The optimum pH was 7.7 for free lipase, but shifted to 8.3-8.5 for immobilized lipases. The optimum temperature was determined to be 35 ℃ for the free enzyme, but 42-44℃ for the immobilized ones, respectively. In addition, the thermal stability, reusability, and storage stability of the immobilized lipase were obviously improved compared to the free one.     

Rapid on‐line system for preliminary screening of lipase inhibitors from natural products by integrating capillary electrophoresis with immobilized enzyme microreactor

An on‐line system for preliminary screening lipase inhibitors from natural products with an immobilized lipase microreactor coupled to capillary electrophoresis was established. In this research, the lipase was anchored on the amino activated capillary inner wall using glutaraldehyde as a homobifunctional linker through Schiff base reaction. The immobilized lipase activity was evaluated by measuring the peak area of the hydrolyzate of p‐nitrophenyl acetate. In order to maintain the enzymatic activity of immobilized lipase, the acetonitrile content and the pH of the reaction solution were also optimized. Under the optimized reaction conditions, the Michaelis–Menten constant of the immobilized lipase and the half maximal inhibitory concentration for orlistat were studied, which were consistent with previous literature data. Furthermore, the developed method was applied to screen lipase inhibition activity from ten natural products. As a result, we found that six natural products have inhibitory effect on the activity of lipase, among which the inhibitory effect of Rhizoma atractylodis extract has never been reported before.     

脂肪酶的固定化及其在有机酶促反应中稳定性研究

利用吸附法,将圆柱状假丝酵母脂肪酶固定于４种疏水性不同的载体上,固定化酶的活性及稳定性随载休疏水性的增大而增大。用ＹＧＷ－Ｃ６Ｈ５作为载体,在有机溶剂－水双液相体系中催化萘普生甲酯的不对称水解,反应１２０ｈ转化率为２４．７２％,产品的对映体过量值为９４．８２％。     

壳聚糖固定化碱性脂肪酶的研究

以蟹壳为原料提取壳聚糖,用戊二醛作交联剂,将碱性脂肪酶固定于壳聚糖上。同时探讨了一定量干壳聚糖载体与交联剂浓度、给酶量等关系的最适固定化酶条件,并对固定化酶的热稳定性、操作稳定性、米氏常数、最适温度、离子强度的影响以及使用半衰期等理化性质进行探讨。     

单分散磁性纳米粒子固定化猪胰脂肪酶的研究

借助溶热法制备了一种亲水及生物相容良好的Fe3O4磁性纳米粒子,用γ-氨丙基三乙氧基硅烷直接对所得磁性粒子表面改性,然后用戊二醛偶联法制得了固定化猪胰脂肪酶.表征研究显示,所得磁性粒子粒径约200 nm,具有良好的单分散性和磁响应性.考察了戊二醛浓度、给酶量和反应时间对脂肪酶固定化过程的影响,并通过游离酶与固定化酶的比...     

Covalent attachment of Candida rugosa lipase on chemically modified hybrid matrix of polysiloxane-polyvinyl alcohol with different activating compounds

Candida rugosa lipase was immobilized by covalent binding on hybrid matrix of polysiloxane–polyvinyl alcohol chemically modified with different activating agents as glutaraldehyde, sodium metaperiodate and carbonyldiimidazole. The experimental results suggested that functional activating agents render different interactions between enzyme and support, producing consequently alterations in the optimal reaction conditions. Properties of the immobilized systems were assessed and their performance on hydrolytic and synthetic reactions were evaluated and compared with the free enzyme. In hydrolytic reactions using p-nitrophenyl palmitate as substrate all immobilized systems showed higher thermal stability and optima pH and temperature values in relation to the free lipase. Among the activating compounds, carbonyldiimidazole resulted in a total recovery of activity on the support and the highest thermal stability. For the butyl butyrate synthesis, the best performance (molar conversion of 95% and volumetric productivity of 2.33 g L⁻¹ h⁻¹) was attained with the lipase immobilized on POS–PVA activated with sodium metaperiodate. The properties of the support and immobilized derivatives were also evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopies and chemical composition (FTIR).     

亲水梳状环氧聚合物载体柔性固定化脂肪酶

以氯乙酰化聚苯乙烯微球载体为大分子引发剂,以甲基丙烯酸缩水甘油酯和亲水性丙烯酰胺为共聚接枝单体,以氯化亚铜及2,2'-联吡啶为催化体系,采用原子转移自由基聚合法接枝合成了具有柔性链的亲水梳状环氧聚合物载体PS-acyl-P(AM-co-GMA),并将其用于耐有机溶剂YCJ01脂肪酶的共价柔性固定化.结果表明,固定化酶催...     

Preparation and characterization of lipase immobilized on reversibly soluble-insoluble N-(2-carboxylbenzoyl) chitosan

N-(2-carboxylbenzoyl) chitosan (CBC), a reversibly soluble-insoluble polymer with pH change, was prepared by modifying chitosan backbone with phthalic anhydride and employed as carrier for lipase immobilization. The obtained CBC exhibited reversible solubility in aqueous solution; it was soluble at pH above 3.8 and precipitated at pH below 3.4. The porcine pancreatic lipase was covalently immobilized on CBC with glutaraldehyde as the crosslinking agent. Under the optimal immobilization condition, the retention activity of the immobilized lipase was found to be 69.8 %. The maximum activity of lipase immobilized on CBC was observed at 40 °C, pH 8.0, while the free lipase presented maximum activity at 37 °C, pH 7.5. The lipase immobilized on CBC exhibited improved thermal and storage stabilities and retained 58.7 % of its initial activity after 9 times of repeated use.     

IMMOBILIZATION OF LIPASE FROM PORCINE PANCREAS ON POLY （METHYL ACRYLATE）COPOLYMERS

A series of poly(methyl acrylate) copolymers of different pore structures were synthesized and functionalized by polyethylene polyamine.The lipase from porcine pancreas was adsorbed on these polymer carriers. It was found that the proe structure and functional group were basic factors which affected the activity of immobilized lipase,The optimal conditions for adsorbing lipase were studied and the effects of pH,ionic strength and temperature on the immobilized lipase were compared with those on the dissolved lipase.