Two rhodamine lactam modulated lysosome-targetable fluorescence probes for sensitively and selectively monitoring subcellular organelle pH change

Abstract

Be a powerful technique for convenient detection of pH change in living cells, especially at subcellular level, fluorescent probes has attracted more and more attention. In this work, we designed and synthesized three rhodamine lactam modulated fluorescent probes RS1, RS2 and RS3, which all respond sensitively toward weak acidity (pH range 4-6) via the photophysical property in buffer solution without interference from the other metal ions, and they also show ideal pKa values and excellent reversibility. Particularly, by changing the lone pair electrons distribution of lactam-N atom with different conjugations, RS2 and RS3 exhibit high quantum yield, negligible cytotoxicity and excellent permeability. They are suitable to stain selectively lysosomes of tumor cells and monitor its pH changes sensitively via optical molecular imaging. The above findings suggest that the probes we designed could act as ideal and easy method for investigating the pivotal role of H(+) in lysosomes and are potential pH detectors in disease diagnosis through direct intracellular imaging.

New Pyridine-Bridged Ferrocene–Rhodamine Receptor for the Multifeature Detection of Hg2+ in Water and Living Cells

“…To a solution of rhodamine B spirolactam I (prepared as the known procedure, 51 0.320 g, 0.6 mmol) and Et 3 N (1.0 mL) in anhydrous CH 2 Cl 2 (10.0 mL) was added dropwise a solution of ferrocenylformyl chloride (0.298 g, 1.2 mmol) in anhydrous CH 2 Cl 2 (10.0 mL) at 0–5 °C. The resulting mixture was stirred at room temperature for 12 h. After the completion of the reaction the resultant solution was added to ice water, and the organic phase was washed with saturated NaHCO 3 and brine and then dried over anhydrous MgSO 4 .…”

Benefits and applications of microwave-assisted synthesis of nitrogen containing heterocycles in medicinal chemistry

“…Despite the large number and efficacy of b-lactam compounds on the market, the increasing drug resistance among pathogenic bacteria claims the need for new antibiotic compounds. Besides their most notable use as antibiotics, substitutions on the pharmacophore groups make them versatile molecules with a broad range of medicinal uses, 94 such as thrombin inhibitors, anti-hyperglycemic agents, anti-cancer agents, anti-proliferative agents, anti-HIV agents, uorescent probes, 95 antimalarial agents, 96 antifungal agents, anti-tubercular agents, antioxidants, antimalarial agents and anti-fungal agents. A further development of blactams is their conversion to spirocyclic nuclei that show antidiabetic, anti-inammatory, analgesic, anticancer and peptidomimetic properties.…”

A magnetic molecularly imprinted optical chemical sensor for specific recognition of trace quantities of virus

“…The viability of Chinese hamster broblast cells under different treatments was evaluated by performing the 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay according to the literature. 20,29,30 Briey, 100 mL of cells (8 Â 10 4 cells mL À1 ) were seeded in a 96-well plate and incubated with cell culture medium for 24 h at 37 C in a humidied environment containing 5% CO 2 . The cells were further incubated with different concentrations (0, 1, 3, 10, 30, and 100 mg mL À1 ) of NIPs for another 24 h at 37 C. Subsequently, 20 mL of freshly prepared MTT (5 mg mL À1 ) solution was added to each well, and then the plates were incubated for an additional 4 h. Formazan crystals were dissolved with DMSO, and the absorbance was measured at 490 nm with a microplate reader.…”