Benzothiazole-substituted benzofuroquinolinium dyes as new fluorescent probes for G-quadruplex DNA

A series of new benzothiazole-benzofuroquinoline conjugates were designed and synthesized to enhance the performance for the application as a G-quadruplex fluorescent probe. All compounds were characterized and the selectivity, sensitivity, and stability of these dyes interacting with G-quadruplex were studied by using fluorescence titration, native PAGE experiments, FRET and CD analysis. Significant enhancement of fluorescent quantum yield was ob served when the compound bound with HRAS G-quadruplex. The results indicate that these compounds show much stronger binding affinity and fluorescent response to G-quadruplex than our previously reported benzothiazole-benzofuroquinoline core scaffold (CYTO) due to the incorporation of a specific amino moiety. The application of these new compounds as a fluorescent agent for living cell imaging was also demonstrated. Copyright © 2015 Published by Elsevier Ltd.