2,4‐Dinitrobenzenesulfonyl Fluoresceins as Fluorescent Alternatives to Ellman's Reagent in Thiol‐Quantification Enzyme Assays

Fluorescent sensor for thiols: Deprotection of nonfluorescent 1 by thiols (R′SH) proceeds rapidly and near-quantitatively in aqueous solution (pH 7.4) to produce highly fluorescent 2. Assays performed in the presence of 1 provide a rapid and simple method for the determination of inhibitory constants for inhibitors such as donepezil toward acetyl- and butyrylcholinesterases. Supporting information for this article, including experimental procedures and spectral data for 5, is available on the WWW under http://www.angewandte.org or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.