TY - JOUR

T1 - 4-Azidocinnoline—Cinnoline-4-amine Pair as a New Fluorogenic and Fluorochromic Environment-Sensitive Probe

AU - Danilkina , Natalia A.

AU - Andrievskaya , Ekaterina V.

AU - Vasileva , Anna V.

AU - Lyapunova, Anna G.

AU - Rumyantsev, Andrey M.

AU - Kuzmin , Andrey A.

AU - Bessonova, Elena A.

AU - Balova , Irina A.

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

PY - 2021/12/1

Y1 - 2021/12/1

N2 - A new type of fluorogenic and fluorochromic probe based on the reduction of weakly fluorescent 4-azido-6-(4-cyanophenyl)cinnoline to the corresponding fluorescent cinnoline-4-amine was developed. We found that the fluorescence of 6-(4-cyanophenyl)cinnoline-4-amine is strongly affected by the nature of the solvent. The fluorogenic effect for the amine was detected in polar solvents with the strongest fluorescence increase in water. The environment-sensitive fluorogenic properties of cinnoline-4-amine in water were explained as a combination of two types of fluorescence mechanisms: aggregation-induced emission (AIE) and excited state intermolecular proton transfer (ESPT). The suitability of an azide–amine pair as a fluorogenic probe was tested using a HepG2 hepatic cancer cell line with detection by fluorescent microscopy, flow cytometry, and HPLC analysis of cells lysates. The results obtained confirm the possibility of the transformation of the azide to amine in cells and the potential applicability of the discovered fluorogenic and fluorochromic probe for different analytical and biological applications in aqueous medium

AB - A new type of fluorogenic and fluorochromic probe based on the reduction of weakly fluorescent 4-azido-6-(4-cyanophenyl)cinnoline to the corresponding fluorescent cinnoline-4-amine was developed. We found that the fluorescence of 6-(4-cyanophenyl)cinnoline-4-amine is strongly affected by the nature of the solvent. The fluorogenic effect for the amine was detected in polar solvents with the strongest fluorescence increase in water. The environment-sensitive fluorogenic properties of cinnoline-4-amine in water were explained as a combination of two types of fluorescence mechanisms: aggregation-induced emission (AIE) and excited state intermolecular proton transfer (ESPT). The suitability of an azide–amine pair as a fluorogenic probe was tested using a HepG2 hepatic cancer cell line with detection by fluorescent microscopy, flow cytometry, and HPLC analysis of cells lysates. The results obtained confirm the possibility of the transformation of the azide to amine in cells and the potential applicability of the discovered fluorogenic and fluorochromic probe for different analytical and biological applications in aqueous medium

KW - AIE and ESPT fluorescence mechanisms

KW - Amines

KW - Azides

KW - Cinnolines

KW - Environment-sensitive probe

KW - Fluorescence

KW - Fluorochromic probe

KW - Fluorogenic probe

KW - Richer cyclization

UR - http://www.scopus.com/inward/record.url?scp=85121548664&partnerID=8YFLogxK

U2 - https://doi.org/10.3390/molecules26247460

DO - https://doi.org/10.3390/molecules26247460

M3 - Article

VL - 26

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 24

M1 - 7460

ER -