Tuning of environment-sensitive 3-hydroxychromone fluorophores based on strong donor substituents in positions 2 or 7

GIORDANO, LUCIANA; SHVADCHAK, VOLODYMYR V. ; ARRUPÉ, NICOLAS ; LOCKHART, LISANDRO J. FALOMIR; SÁNCHEZ, VERÓNICA M; JOVIN, THOMAS M.

Dyes and Pigments

Elsevier Ltd

Año: 2023 vol. 218

We have synthesized a series of environmentally sensitive fluorophores based on 3-hydroxychromone withsystematically varied aromatic groups at positions 2 and 7. The two families of 2,7-diaryl-3-hydroxychromoneswere synthesized using Suzuki coupling from the corresponding 2-aryl-7-bromo-3-hydroxychromones. Thesechromophores exhibit a dual fluorescent emission and a strong response to changes in environmental polarity inorganic solvents. Both experimental determination and calculations of dipole moment changes show strongercharge transfer in compounds with an electron donor group at position 7 compared to position 2. Their emissionis almost totally quenched in the aqueous medium, while the increase in quantum yield upon binding to biological molecules serves as a useful characteristic. Particularly, compounds with strong donors in position 7 aresensitive to diverse lipid environments, whereas those with strong donors in position 2 have different emissionprofiles for distinct protein interactions. The complex behavior of the probes was evaluated using spectral phasoranalysis. Altogether, these novel families of probes may help monitor several biological processes in vitro and incell cultures.