Modeling techniques and fluorescence imaging investigation of the interactions of an anthraquinone derivative with HSA and ctDNA

• A new anthraquinone derivative (AORha) was synthesized.
• The mechanisms between AORha and HSA, ctDNA were studied simultaneously.
• HepG2 cells were used for cell viability assay and cell imaging experiment.
• The binding constant, binding site and distance of hydrogen bond were also obtained.

A new anthraquinone derivative (AORha) was synthesized. Its interactions with human serum albumin (HSA) and calf thymus DNA (ctDNA) were investigated by fluorescence spectroscopy, UV–visible absorption spectroscopy and molecular modeling. Cell viability assay and cell imaging experiment were performed using cervical cancer cells (HepG2 cells). The fluorescence results revealed that the quenching mechanism was static quenching. At different temperatures (290, 300, 310 K), the binding constants (K) and the number of binding sites (n) were determined, respectively. The positive ΔH and ΔS values showed that the binding of AORha with HSA was hydrophobic force, which was identical with the molecular docking result. Studying the fluorescence spectra, UV spectra and molecular modeling also verified that the binding mode of AORha and ctDNA might be intercalative. When HepG2 cells were treated with AORha, the fluorescence became brighter and turned green, which could be used for bioimaging.

CLSM images of HepG2 cells incubated with 1.42 × 10− 7 M of AORha for 3 h at 37 °C, (a) bright field (A, D), (b) bright field + fluorescence (B, E) excited at 458 nm, (c) fluorescence (C, F).Figure optionsDownload as PowerPoint slide