Mono-substituted corroles containing morpholinyl, piperidyl and pyrrolidinyl units: Photophysics, photobiology and biomolecular interaction studies

A classical approach is reported to design meso-mono-substituted corroles with bioactive heterocycle units. The studied corroles were obtained by the classical Gryko methodology, with yields ranging from 18 to 33 %. Corroles were fully characterized by elemental analysis, high-resolution mass analysis, nuclear magnetic resonance and electrochemical analysis. Spectroscopic assays by ultraviolet-visible absorption, steady-state fluorescence and time-resolved fluorescence emission, with density functional theory (DFT) calculations are conducted. In this sense, the obtained corroles presented absorption spectra typical of tetrapyrrolic macrocycles and emission peaks centered in the red region, with low fluorescence quantum yields and short lifetimes (between 3.0 and 4.05 ns).

Photobiological parameters such as photostability and reactive oxygen species (ROS) generation were also assessed, showing good photostability of the derivatives and generation of singlet oxygen (¹O₂) and superoxide radicals (O₂^•–) species. Finally, spectroscopic, viscometer studies and molecular docking calculations revealed the ability of each corrole derivative to interact with salmon-sperm DNA (SS-DNA) and human serum albumin (HSA) biomacromolecules, suggesting better interactions in the minor grooves of DNA and interaction in site III of albumin.