Synthesis of quinolyl-pyrrole derivatives as novel environment-sensitive fluorescent probes

Publication date: Available online 31 May 2019Source: Journal of Photochemistry and Photobiology A: ChemistryAuthor(s): Ryo Shinotsuka, Toru Oba, Takahiro Mitome, Takuto Masuya, Satoshi Ito, Yukie Murakami, Tomoko Kagenishi, Yutaka Kodama, Masaru Matsuda, Takashi Yoshida, Minoru Wakamori, Masamichi Ohkura, Junichi NakaiAbstractWe synthesized novel environment-sensitive fluorophores using a unique fluorogenic core quinolyl-pyrrole (QP, 2-(1H-pyrrol-2-yl)quinoline). QP was obtained from isatins and 2-acetylpyrrole by Pfitzinger quinoline synthesis. Derivatization at the quinoline and pyrrole rings was carried out using the Sonogashira–Hagiwara cross coupling and Vilsmeier–Haack reactions, respectively. The obtained dyes showed strong fluorescence solvatochromism, but their absorption spectra remained nearly unchanged. The introduction of a dimethylaminophenylethynyl moiety at the quinoline side of the QP resulted in a change in the fluorescence color from blue to red within a narrow relative permittivity range of roughly 2 – 10, demonstrating that the substitution strengthened the sensitivity of the dye to the low polarity environment. The dye also reflected voltage changes across liposomal membranes, showing a 3.7-fold enhanced fluorescence intensity when tested under the same conditions as di-4-ANEPPS, a popular voltage sensitive dye, which only changed its fluorescence intensity by a factor of 1.2. The voltage sensitivity of the dye was calculated to be 2.3%/mV, much l...
Source: Journal of Photochemistry and Photobiology A: Chemistry - Category: Chemistry Source Type: research