A negative-solvatochromic fluorescent probe for visualizing intracellular distributions of fatty acid metabolites

Abstract

Metabolic distribution of fatty acid to organelles is an essential biological process for energy homeostasis as well as for the maintenance of membrane integrity, and the metabolic pathways are strictly regulated in response to environmental stimuli. Herein, we report a fluorescent fatty acid probe, which bears an azapyrene dye that changes its absorption and emission features depending on the microenvironment polarity of the organelle into which it is transported. Owing to the environmental sensitivity of this dye, the distribution of the metabolically incorporated probe in non-polar lipid droplets, medium-polarity membranes, and the polar aqueous regions, can be visualized in different colors. Based on density scatter plots of the fluorophore, we demonstrate that the degradation of triacylglycerols in lipid droplets occurs predominantly via lipolysis rather than lipophagy in nutrition-starved hepatocytes. This tool can thus be expected to significantly advance our understanding of the lipid metabolism in living organisms.

NIR Mitochondrial Fluorescent Probe for Visualizing SO2/Polarity in Drug Induced Inflammatory Mice

“…BTHP was synthesized by condensation reaction of benzopyran derivatives and benzothiazole derivatives. The hydroxyl group in the structure of benzothiazole derivatives has a tendency to dissociate protons in highly polar solvents. − After deprotonation, the probe shows a new absorption peak at about 760 nm and a new fluorescence emission peak at about 830 nm. The carbon–carbon double bond in benzopyran derivatives can undergo Michael addition reaction, and the conjugated structure is destroyed with red light quenching, which can be used to detect SO 2 .…”

Seeking for Optimal Excited States in Photoinduced Electron-Transfer Processes─The Case Study of Brooker’s Merocyanine

“…It occurs for “negatively” solvatochromic dyes. It thus corresponds to a backward CT or to a “light”-induced dipole moment decrease, that is, a reduced dipole moment in the ES (see, e.g., refs – ). In that case, where charge transports back from A to D upon photoexcitation ([D – –π–A + ]* ES) in contrast to what happens for the traditional positive solvatochromic dyes, the solvatochromism phenomenon exhibits a hypsochromic (or negative) shift with the increase in solvent polarity (i.e., decrease of band transition energy).…”

A multi-modal probe for trace water and simultaneously monitoring lipid droplets and lysosomes

“…In recent years, fluorescent probes have attracted considerable attention due to their easy portability, low cost and rapid response, and their fluorescence imaging has induced some impressive progress in the field of biomedical optical imaging and environmental monitoring. [1][2][3][4][5][6][7][8][9][10][11] At present, most of the reported probes can only detect and image a single target in biological 12 and environmental systems. [13][14][15] To detect two or more targets simultaneously, a method in which two probes act on different targets in combination has been usually used.…”