Synthesis, optical properties, and cellular imaging of novel quinazolin-2-amine nopinone derivatives

•Novel quinazolin-2-amine derivatives were designed and synthesized from nopinone.•Quinazolin-2-amine derivatives had fluorescent properties in the solid and solution states.•Quinazolin-2-amine derivatives had little cytotoxicity to L02 cells.•Quinazolin-2-amine derivatives can be used for cellular imaging.

Quinazolin-2-amine derivatives (4–6) were successfully synthesized from β-pinene derivative nopinone and characterized by Fourier transform infrared spectroscope (FT-IR), nuclear magnetic resonance (NMR), mass spectrometry, and X-ray single crystal diffraction. Then, their optical and thermal properties were characterized with ultraviolet–visible spectroscopy, photoluminescence (PL) spectroscopy, thermogravimetric analysis, and confocal fluorescent microscopic imaging. Three target compounds had enhanced fluorescence in solid and solution states and fluorescent quenching occurred when acid or base was added to the solution. Thermal decomposition temperatures of compounds 4–6 were 138, 290, and 291 °C, respectively and no compound was cytotoxic to normal L02 hepatocyte cells, and confocal fluorescent microscopic imaging in human lung A549 adenocarcinoma cells was realized using these compounds. These new fluorescent compounds may be candidates for future fluorescent bio-imaging agents.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide