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901.
902.
Xiao Yan Wu Sanna JÄÄskelÄinen Wu-Yen Linko 《Applied biochemistry and biotechnology》1996,59(2):145-158
A commercialRhizomucor miehei lipase was purified by ammonium sulfate precipitation. Phenyl Sepharose 6 Fast Row hydrophobic interaction chromatography,
and DEAE Sepharose Fast Flow anion-exchange chromatography. The recovery of lipase activity was 32% with a 42-fold purification.
The molecular size of the purified enzyme was 31,600 Dalton and the pI 3.8. The enzyme was stable for at least 24 h within
a pH range of 7.0-10.0, and 96.8% of the enzyme activity remained when kept at 30‡C for 24 h. Further, about 10–30% of the
lipase activity was inhibited by K+, Li+, Ni+, Co2+, Zn2+, Mg2+, Sn2+, Cu2+, Ba2+, Ca2+, and Fe2+ ions and by SDS, but EDTA had no effect. Under the experimental conditions, the optimum temperature for the hydrolysis of
olive oil was 50‡C (pH 8.0), and for the synthesis of 1-butyl oleate, 37‡C. It was concluded that hydrolytic activity of lipase
alone is not a sufficient criterion for its synthetic potential. The optimal molar ratio of oleic acid and 1-butanol was 2:1
for 1-butyl oleate synthesis. The 1-butyl oleate yield was unaffected by purification of the enzyme after 12 h. 相似文献
903.
Guo DJ Xiao SJ Xia B Wei S Pei J Pan Y You XZ Gu ZZ Lu Z 《The journal of physical chemistry. B》2005,109(43):20620-20628
Both end-functionalized (alpha-bromo and omega-carboxy) compounds were first tested for the radical reaction on the silicon-hydride (Si-H) terminated porous silicon (PSi) with/without the presence of diacyl peroxide initiator under microwave irradiation. Then the carboxylic acid monolayers (CAMs) assembled on PSi through the robust Si-C bonds were converted to amino-reactive linker, N-hydroxysuccinimide (NHS)-ester, terminated monolayers. And finally two proteins of bovine serum albumin (BSA) and lysozyme (Lys) were immobilized through amide bonds. The optimum PSi membrane for protein immobilization without collapse, with parameters of porous radii 4-10 nm and depth 0.2-4.6 mum, was prepared from the (100)-oriented p-type silicon wafer. The chemically converted surface products were monitored with Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM). 相似文献
904.
905.
906.
合成了含Mo(0)的三核化合物(Et4N)2[(CO)4Mo(μ-S)2Mo(μ-S)2Mo(CO)4](Ⅰ)和(Et4N)2[(CO)4Mo(μ-S)2W(μ-S)2Mo(CO)4](Ⅱ),测定了(Ⅰ)的晶体结构.Ⅰ属单斜晶系,空间群P2相似文献
907.
Two novel sesquiterpene dimers, compounds 1 and 2 , were isolated from the rhizome of Ligularia virgaurea, together with the six known sesquiterpenoids 3 – 8 . Their structures were established by physico‐chemical and spectroscopic methods, especially by means of 1D‐ and 2D‐NMR as well as HR‐MS analyses. A mechanism based on a classical Diels–Alder cyclization is proposed for the formation of the dimer 1 from the precursors 8 and the quinone form of 6 (Scheme). 相似文献
908.
A novel coordination polymer [(C10H16N)2(Pb2I6)·2DMF·H2O]n (C10H16N=N-butyl-2-Methy-Pyridinium) was synthesized by the reaction of Pb(NO3)2 with C6H10NI at room temperature in DMF solvent and structurally characterized by means of X-ray single diffraction. The title compound crystallizes in triclinic system, space group P1 with a=1.1237(2) nm, b=1.25330(16) nm, c=0.808 00(12) nm, α=102.523(4)°, β=92.475(5)°, γ=95.712(10)°, V=1.102 9(3) nm3, Z=1, Dc=2.470 Mg·m-3, F(000)=738, chemical formula C26H48N4O3Pb2I6 and Mr=1 640.46, μ(MoKα)=11.849 mm-1, the final R=0.057 8 and wR=0.166 5 for 3716 observed reflections with I > 2σ(I). The title compound consists of cations ([(C10H16N)+] and anion chain(PbI3-),they are combined by static attracting forces in the crystal. DMF and H2O locate between the organic and inorganic moiety. CCDC: 210812. 相似文献
909.
含噁二唑单元共轭聚合物合成与性质研究 总被引:12,自引:0,他引:12
单体 2 ,5 双 (4 溴苯 ) 1,3,4 二唑 (M Ⅰ )与 1,4 二乙烯基 2 ,5 二正丁氧基苯 (M Ⅱ ) ,在钯催化下通过Heck偶合反应合成得到共轭聚合物 ;单体和聚合物进行了1 H NMR ,1 3C NMR、质谱、FT IR、UV、荧光光谱、GPC、元素分析、热分析等测试 ;二唑 (OXD)基团是一种很好的生色团 ,对氧和热特别稳定 ,二唑环的亲电子性能使其特别适合于作为电子传输层 ,聚合物能发射很强的绿色荧光 ,它将是一类潜在的光电高分子材料 相似文献
910.
手性5-l-(艹孟)氧基丁内酯并[3,4-d]-3-取代基-异(口恶)唑啉类化合物的合成 总被引:2,自引:0,他引:2
研究了手性元5-(R)-(l-(艹孟)氧基)-2(5H)-呋喃酮与取代苯甲醛肟以次氯酸钙作为氧化剂进行的区域选择性原位1,3-偶极环加成反应,同步生成两个新的手性中心,得到了一系列光学纯丁内酯并[3,4-d]-3-取代基-异(口恶)唑啉类化合物;应用波谱学手段及X射线单晶衍射法确证了产物的绝对构型,并对产物的核磁共振氢谱规律性加以总结. 相似文献