酶法催化柚皮苷制备根皮素及其抗氧化活性分析

本文阐述一种高效,环保制备高价值天然抗氧化剂根皮素的方法。以天然的柑橘提取物柚皮苷为原料,经一锅法加氢反应制得柚苷二氢查尔酮,再以α-鼠李糖苷酶(α-rhamnosidase)和纤维素酶(cellulase)高效催化水解而制得根皮素。采用单因素和正交实验对α-鼠李糖苷酶和纤维素酶酶解反应的p H、温度、酶与底物比进行优化,同时对根皮素、三叶苷、柚苷二氢查尔酮、柚苷的抗氧化性进行了研究,结果表明:α-鼠李糖苷酶(α-rhamnosidase)酶解最佳工艺为温度60℃、p H 4、酶与底物比为0.6:1;纤维素酶(cellulase)最佳工艺为温度45℃、p H 5.5、酶与底物比为0.3:1。在此工艺下根皮素的转化率为96.10%,比原工艺提高了10.53%。抗氧化性研究结果为:清除DPPH自由基能力根皮素(0.18±1.45)>三叶苷(0.3±1.63)>柚苷二氢查尔酮(0.95±1.24)>柚苷(8±1.97),还原铁离子能力为根皮素(7.1±0.68)>三叶苷(2.51±0.75)>柚苷二氢查尔酮(2.05±0.58)>柚苷(0.11±0.92)。本方法条件温和,周期短且转化率高,易于放大生产。抗氧化性结果表明根皮素具有较高的抗氧化性。这对根皮素的放大生产及应用具有重大意义。

Synthesis and Structural Characterization of Bis(2,2'-bpy)bis(azide)cobalt(Ⅲ)nitrate dihydrate

The title complex [CoIII(2, 2?bpy)2(N3)2]種O3?H2O was obtained by an auto-oxidization reaction of cobalt nitrate with 2, 2-bpy and sodium azide in aqueous solution at room temperature, and violet single crystals were prepared in ethanol solution. The structure was determined by X-ray crystallography. The crystal is of triclinic, space group P ?with a = 8.285(4), b = 11.990(8), c = 12.596(7) ? a = 86.630(3), b = 86.280(5), g = 71.130(10)? C20H20CoN11O5, Mr = 553.40, Z = 2, V = 1180.6(12) ?, F(000) = 568, Dc = 1.557 g/cm3, m = 0.784 mm-1, R = 0.0403 and wR = 0.1008. The title complex consists of a [CoⅢ(2, 2?bpy)2(N3)2]+ cation, a NO3- anion and two lattice water molecules. The center CoⅢ ion coordinated by two chelating 2, 2?bpy ligands and two terminal azide groups with a CoN6 coordination environment exhibits a distorted octahedral geometry.

生物酶法制备淫羊藿素工艺条件的研究

利用β-葡萄糖苷酶酶解淫羊藿苷、得淫羊藿素,通过对温度,pH,缓冲液倍数,底物与酶比,酶解时间5个因素设计单因素实验,并在单因素实验的基础上设计正交实验,优化工艺条件,以提高淫羊藿素的转化率。正交实验结果表明,对转化率影响最大的因素是pH,最小是底物与酶比;最佳工艺条件下(温度50℃、pH为5、酶解时间为20 h、底物与酶比为6∶1)的转化率为95.73%。

Synthesis and Crystal structure of Poly{[Co(4,4'-bpy)(H_2O)_4]SO_(4·)(4-abaH)_(2·)3H_2O}

The title complex has been obtained by the reaction of cobalt sulfate heptahydrate with 4,4?-bpy and 4-abaH (4,4?-bpy = 4,4?-bipyridine, 4-abaH = 4-aminobenzonic acid) in ethanol solution, and its structure was determined by X-ray crystallography with the following data: tetragonal, space group P42/n, Mr = 5692.46, Co8C192H288N32O120S8, a = b = 16.402(5), c = 22.750(5) ?, Z = 1, V = 6120(2) ?3, F(000) = 2968, Dc = 1.544 g/cm3, μ = 0.707 mm-1, the final R = 0.0786 and wR = 0.1935 for 2673 observed reflections (I > 2σ(I)). The title complex consists of polymeric [Co(4,4?-bipy)(H2O)4]2+ cation chains, SO4 2- anions, lattice 4-abaH and water mole- cules. The center CoII ions are connected by bridging 4,4?-bpy ligands exhibiting one-dimensional chains, and coordinated by four water molecules into a distorted octahedral geometry. These chains are further extended by hydrogen bonds among SO4 2- anions, coordinated and lattice water molecules as well as lattice 4-abaH molecules into a three-dimensional network.② Corresponding author. male, 48, associate professor, research interest in coordination chemistry. E-mail: thjchen@jnu.edu.cn② Corresponding author. male, 48, associate professor, research interest in coordination chemistry. E-mail: thjchen@jnu.edu.cn

α-L-鼠李糖苷酶基因的重组表达及其应用

以来源于Thermotogapetrophila的α-L-鼠李糖苷酶为目标,将TpdRha重组于毕赤酵母细胞中,成功构建重组表达菌株GS115-TpdRha和KM71H-TpdRha。经甲醇诱导发酵后得到粗酶液,所得粗酶液均具有催化橙皮苷水解为橙皮素单葡萄糖苷的活性,转化率分别为25.38%和36.64%。因此,KM71H-TpdRha更有利于表达TpdRha,在催化生产橙皮素单葡萄糖苷及其他天然产物上有良好的应用潜力,可为产业化生产新橙皮苷及NHDC奠定物质基础。

ASM连接器设计简介

高速连接器是数据传输通讯物理链路中的一个关键节点,其电性能及应用操作性能会影响数据传输的可靠性及整体数据的传输。本文通过对自研ASM高速连接器设计的主要点做基本介绍,为同类产品后续开展类似设计提供参考。其中,ASM连接器是OmniEdge ASM连接器的缩写。

曝气生物滤池及模块化装备用于城市黑臭水体治理

惠州某河道主要支流水污染治理项目实施了截污、补水工程,以超磁+曝气生物滤池为核心工艺,将截留污水进行就地处理排回河道,实现水体的净化及循环流动,满足生态景观要求。实际工程运行结果表明,曝气生物滤池技术具有停留时间短、占地小的特点,处理后出水水质优于《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准,其中COD、NH_(3)-N达到《地表水环境质量标准》(GB 3838—2002)Ⅴ类标准,同时采用模块化装备的建造模式,安装便捷,建设周期短,可异地搬迁,尤其适用于城市黑臭水体治理分散式就地处理工程。

上向流反硝化深床滤池用于污水厂提标改造

广东省某水质净化厂一期工程原采用SBR+纤维转盘滤池为主体的工艺,提标改造后要求主要出水指标达到《地表水环境质量标准》(GB 3838—2002)的Ⅴ类标准(TN≤15 mg/L),实际出水TP偶尔超标,TN严重超标。提标改造工程在现有SBR工艺后端新增上向流反硝化深床滤池模块化水处理装备,出水COD≤30 mg/L、BOD_(5)≤6 mg/L、TN≤12 mg/L、TP≤0.3 mg/L、SS≤5 mg/L,达到了地表水准Ⅳ类标准,表明上向流反硝化深床滤池脱氮除磷效果好,尤其是脱氮效率较高,最大TN去除量高达29.4 mg/L,相应的反硝化负荷达到2.08 kgNO_(3)^(-)-N/(m^(3)·d)。

两级上向流生物滤池模块化装备用于污水厂提标改造

部分城市生活污水处理厂的进、出水水质随季节性波动较大。以山西省平定县县城污水处理厂为例,按《地表水环境质量标准》(GB 3838—2002)准Ⅴ类(TN≤10 mg/L)标准考核,该污水厂夏季出水TN不能达标,冬季NH3-N不能达标,通过新增两级生物滤池的深度处理工艺,采用上向流生物滤池及专有的布水布气系统,可根据水质处理需求实现硝化与反硝化模式的切换,保证TN及NH3-N全年稳定达标。该项目采用智能模块化装备的建造模式,具有安装便捷、占地面积小、不受施工场地限制等优势。