Synthesis of Organoselenium-Modifiedβ-Cyclodextrins Possessing a 1,2-Benzisoselenazol-3(2H)-one Moiety and Their Enzyme-Mimic Study

Abstract

Six novel H 2 O-soluble b-cyclodextrin derivatives containing a 1,2-benzisoselenazol-3(2H)-one moiety were synthesized by a convenient method in 25 ± 60% yield and characterized by MS, elemental analysis, IR, 1 H-NMR, and UV/VIS spectroscopy. The conformations of these b-cyclodextrin derivatives 1 ± 6 were analyzed by circular dichroism and fluorescence-lifetime experiments. The superoxide dismutase (SOD) activities of 1 ± 6 were determined by auto-oxidation of pyrogallol at 25.08 in buffer solution (pH 8.2), giving relatively high SOD activities of up to 121 ± 330 U/mg. Also, the glutathione peroxidase (GPX) activities of hosts 1 ± 6, determined by the method of Wilson at 378 in buffer solution (pH 7.0), show good GPX activities in the range of 0.34 ± 0.86 U/mmol. The mimicking results of the bifunctional artificial enzyme models 1 ± 6 were globally compared with regard to their structural and conformational difference.

Carboxyl-ebselen-based layer-by-layer films as potential antithrombotic and antimicrobial coatings

“…C-ebselen was synthesized using a reported method [22] with a minor modification of using anhydrous acetonitrile [23] instead of ether as the solvent in the third step. 1 H NMR, 13 C NMR spectra and mass spectra of C-ebselen were recorded using a Varian MR400 MHz, Varian VNMRS 700 MHz spectrometer and a VG (Micromass) 70–250-S Magnetic sector mass spectrometer (EI, 70eV), respectively.…”

Macrocycles in Bioinspired Catalysis: From Molecules to Materials

“…Numerous CD-based GPx models have been designed via incorporating selenium/ tellurium functional groups on macrocyclic building blocks (Huang et al, 2011). By modification of CD and with ditelluride moiety, 2,2′-ditellurobis (2-deoxy-β-CD) showed excellent GPx-like activity in the presence of substrate thiols (Figure 1B) (Liu et al, 1998;Liu et al, 2000;Liu et al, 2002;Dong et al, 2004;McNaughton et al, 2004;Dong et al, 2006a;Dong et al, 2006b;Dong et al, 2007). When an aromatic substrate was used instead of natural substrate glutathione, the activity could be 200,000-fold more efficiently than the common GPx mimic PhSeSePh (Dong et al, 2004).…”

环糊精在金属酶模拟中的应用

“…Dismukes等直接利用环糊精作配体与Mn离子配 位得到羟基桥联的双核Mn(III)的环糊精配合物 6 作 为绿色植物的光致水氧化酶模型 [23] , 电化学研究表 [25] , 如图 6 所示, 在催化过程中产生的环 糊精自由基可以诱导包合在空腔的底物产生自由基, 从而发生氧化还原或分子内重排反应. Bonomo等用 环糊精伯羟基二取代组胺的铜配合物模拟超氧化物 歧化酶(superoxide dismutase, SOD) [26] , 研究发现 邻位二取代的环糊精衍生物能有效清除超氧负离子 自由基, 其IC 50 值为 0.12 µmol⋅L −1 , 分别比间位取代 [27] , 表 现 出 较 高 的 SOD 活 力 (121~330 U/mg), 表明模型的催化中心和环糊精空腔 的协同作用加速了催化过程. Mikkelsen等用第一面 或第二面羟基修饰二茂铁环糊精模拟半胱氨酸氧化 酶 [28] , 研究发现环糊精第二面修饰的衍生物催化半 胱氨酸氧化的速率为 1470 L⋅mol −1 ⋅s −1 ,明显高于相应 的环糊精第一面修饰物.…”