Department of Science Education-Chemistry Major, Daegu University, GyeongBuk 712-714, South Korea.
Carbohydr Res. 2013 Aug 9;377:18-27. doi: 10.1016/j.carres.2013.05.014. Epub 2013 May 28.
One of the most commonly employed bioorthogonal reactions with azides is copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC, a 'click' reaction). More recently, the strain-promoted azide-alkyne [3+2] cycloaddition (SPAAC, a copper-free 'click' reaction) was developed, in which an alkyne is sufficiently strained to promote rapid cycloaddition with an azide to form a stable triazole conjugate. In this report, we show that an internal alkyne in a strained ring system with two electron-withdrawing fluorine atoms adjacent to the carbon-carbon triple bond reacts to yield covalent adducts not only with azide moieties but also reacts with free sulfhydryl groups abundant in the cytosol. We have identified conditions that allow the enhanced reactivity to be tolerated when using such conformationally strained reagents to enhance reaction rates and selectivity for bioorthogonal applications such as O-GlcNAc detection.
其中一种最常用的含叠氮化物的生物正交反应是铜催化的叠氮化物-炔烃 [3+2]环加成反应（CuAAC，一种“点击”反应）。最近，开发了应变促进的叠氮化物-炔烃 [3+2]环加成反应（SPAAC，一种无铜的“点击”反应），其中炔烃受到足够的应变，可与叠氮化物快速环加成形成稳定的三唑共轭物。在本报告中，我们表明，具有两个相邻的吸电子氟原子的应变环系统中的内部炔烃与叠氮部分反应生成共价加合物，并且还与富含细胞质溶胶的游离巯基反应。我们已经确定了在使用这种构象应变试剂来提高反应速率和选择性以进行生物正交应用（例如 O-GlcNAc 检测）时，可以容忍增强的反应性的条件。
