Institut Européen de Chimie et Biologie, Université de Bordeaux , 2 rue Robert Escarpit, 33607 Pessac, France.
Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS UMR5287 , Bordeaux, France.
J Org Chem. 2018 Feb 16;83(4):2058-2066. doi: 10.1021/acs.joc.7b03004. Epub 2018 Feb 1.
Bioorthogonal fluorescent turn-on reactions are attractive for the sensitive real-time detection of a variety of phenomena including bioconjugation, chemical reactivity, and material assembly. Herein we describe the use of 3,4-disubstituted sydnones, a singular class of mesoionic dipoles, for highly fluorescent turn-on copper-free click cycloadditions with the fluorogenic dibenzocyclooctyne Fl-DIBO. Coherent with time-dependent density functional theory calculations, the pyrazole cycloadducts were found to be highly fluorescent with compelling photophysical properties including excellent fluorescence enhancement (up to 240-fold), high quantum yields (over 45%), and large Stokes shift (over 100 nm). Furthermore, the good stability and reactivity of 4-chlorosydnones with Fl-DIBO allowed us to employ them as chemical reporters for the challenging detection of modified-proteins in complex cellular extracts, with exquisite specificity in no-wash conditions. This novel fluorogenic system significantly expands our chemical biology toolbox and should be beneficial in countless applications.
生物正交荧光开启反应在各种现象的灵敏实时检测中很有吸引力，包括生物缀合、化学反应和材料组装。在此，我们描述了 3,4-二取代的 sydnones（一种独特的介离子偶极子）类化合物在与强荧光的二苯并环辛炔 Fl-DIBO 的铜自由点击环加成反应中的应用。与时间依赖的密度泛函理论计算一致，发现吡唑环加成产物具有很高的荧光性，具有引人注目的光物理性质，包括出色的荧光增强（高达 240 倍）、高量子产率（超过 45%）和大斯托克斯位移（超过 100nm）。此外，4-氯 sydnones 与 Fl-DIBO 的良好稳定性和反应活性使我们能够将其用作复杂细胞提取物中修饰蛋白挑战性检测的化学报告物，在无洗涤条件下具有极高的特异性。这种新型的荧光报告系统极大地扩展了我们的化学生物学工具包，应该在无数的应用中是有益的。
