Synthesis and Application in Cell Imaging of Acridone Derivatives

Tricyclic acridone derivatives have been extensively developed as antimicrobial, antimalarial, and antitumor drugs due to their broad spectrum of drug design and biological activity. In this study, we developed a surfactant-like acridone scaffold that contained two vinylpyridines and a dodecyl pyridine chain. The acridone scaffold decorated the dodecyl pyridine chain by N-bromosuccinimide reagent. The surfactant-like core scaffold incorporated with 4-vinylpyridines at the 2- and 7-positions via a Heck coupling reaction. Subsequently, the acridone derivatives were methylated onto these pyridine groups. Here we developed two similar acridone derivatives, MedAcd12C and MedAcd12P. The MedAcd12C incorporated two pyridine groups, and MedAcd12P incorporated three pyridine groups. MedAcd12C and MedAcd12P have two identical vinylpyridines and the different anchor tails at the N10 position. Their physicochemical properties, cell compatibility, and photoluminescence were demonstrated. Although both compounds have no fluorescence emission in water solution, MedAcd12P and MedAcd12C significantly appeared with orange light emission in the cellular imaging. We suggested that the surfactant-like scaffold promoted the drugs’ self-assembly and caused the aggregation-induced emission (AIE) after cellular uptake. This innovative design endowed acridone derivatives with an AIE and traceability for cell imaging.