绿光光控释放和荧光增强响应的 CO 给体设计、合成及应用

Carbon monoxide (CO) is not only a toxic gas, but also an important gas signaling molecule that plays crucial regulatory roles in various physiological and pathological processes, which include neurotransmission, vasodilation, mitigation of inflammatory response, and anti-cancer activities. Therefore, development of CO donors for controlled release of CO with simutaneous fluorescence signal generation for quantification and tracking purpose is particularly useful for CO signal transduction and quantity-activity relationship studies. Herein, a novel photo-controlled CO donor BODIPY-Fla-1 was designed and synthesized using 3-hydroxyflavone (HF) as the photo-triggered CO-releasing moiety, which is conjugated to a boron-dipyrromethene (BODIPY) fluorophore at its 4' position of B ring via a double-bond linkage. It can achieve photo-triggered CO release under green light-emitting diode (LED) light irradiation and aerobic condition with simutaneous fluorescence turn-on responses at 562 nm for convenient tracking CO release via fluorescence imaging at green channel in live cell studies. It was also verified that the CO released by photolysis of BODIPY-Fla-1 can effectively reduce the level of intracellular superoxide radical and alleviate oxidative stress. This incorporation of a conjugated fluorophore moiety via a double bond linkage provides a new design strategy for development of HF-based CO donors with longer photolysis light and fluorescence response wavelength.