A Bifunctional Spin Label for Ligand Recognition on Surfaces
作者:Michael A. Hollas、Simon J. Webb、Sabine L. Flitsch、Alistair J. Fielding
DOI:10.1002/anie.201703929
日期:2017.8.1
paramagnetic resonance (EPR) of biomolecules spin-labeled with nitroxides can offer uniquely sensitive and selective insights into these processes, but new spin-labeling strategies are needed. The synthesis and study of a bromoacrylaldehyde spin label (BASL), which features two attachment points with orthogonal reactivity is reported. The firstexamples of mannose and biotin ligands coupled to aqueous carboxy-functionalized
acid phenethyl ester, CAPE) and unnatural (N-acetylcysteine, paramagnetic alcohols) antioxidants. The in vitro antioxidant activity was tested by 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, while assays of cell protection against reactive oxygen species were carried out in the presence of 2′,7′-dichlorofluorescein diacetate and H2O2. Paramagnetic esters without phenol
摘要已经研究了新制备的含氮氧化物部分作为潜在抗氧化剂的咖啡酸盐的结构-活性关系,并将其与已知的天然(咖啡酸苯乙酯,CAPE)和非天然(N-乙酰半胱氨酸,顺磁性醇)抗氧化剂的结构-活性关系进行了比较。通过2,2'-叠氮基双(3-乙基苯并噻唑啉-6-磺酸)自由基清除测试体外抗氧化活性,同时在2',7'-二氯荧光素存在下进行细胞对活性氧的保护性测定双乙酸盐和H 2 O 2。没有酚基序的顺磁性酯表现出最低的抗氧化活性,其次是具有中等活性的顺磁性醇。在研究的化合物中,顺磁性酚类化合物是最好的抗氧化剂。由于新的顺磁性CAPE类似物在NIH3T3成纤维细胞中的细胞毒性比10μM时的CAPE小,但具有相似的抗氧化活性,因此可以认为它们是很有前途的抗氧化剂。 图形摘要
Synthesis of Nitroxide-Annulated Carbocycles and Heterocycles
New, pyrroline nitroxide annulated lactones, polycycles, and maleimide were synthesized by classical and microwave-assisted methodology. We report the application of the metathesis reaction in the presence of nitroxide yielding a pyrroline nitroxide condensed 1,4-benzoquinone as a paramagnetic dienophile. The formation of the isoselenazolone-fused pyrroline ring system was examined and different reactivity was observed with pyrrolin-1-oxyl and pyrroline derivatives.
3-Substituted 4-Bromo-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-1-yloxyl Radicals as Versatile Synthons for Synthesis of New Paramagnetic Heterocycles
作者:Tamás Kálai、Mária Balog、József Jekö、Kálmán Hideg