Selective fluorescence detection method for selenide and selenol using monochlorobimane

Bioluminescence Imaging of Selenocysteine in Vivo with a Highly Sensitive Probe

Selenocysteine (Sec), a vital member of reactive selenium species, is closely implicated in diverse pathophysiological states, including cancer, cardiovascular diseases, diabetes, neurodegenerative diseases, and male infertility. Monitoring Sec in vivo is of significant interest for understanding the physiological roles of Sec and the mechanisms of human diseases associated with abnormal levels of Sec. However, no bioluminescence probe for real-time monitoring of Sec in vivo has been reported. Herein, we present a novel bioluminescent probe BF-1 as an effective tool for the determination of Sec in living cells and in vivo for the first time. BF-1 has advantages of high sensitivity (a detection limit of 8 nM), remarkable bioluminescence enhancement (580-fold), reasonable selectivity, low cytotoxicity, and high signal-to-noise ratio imaging feasibility of Sec in living cells and mice. More importantly, BF-1 affords high sensitivity for monitoring Sec stimulated by Na₂SeO₃ in tumor-bearing mice. These results demonstrate that our new probe could serve as a powerful tool to selectively monitor Sec in vivo, thus providing a valuable approach for exploring the physiological and pathological functions and anticancer mechanisms of selenium.

Bivalent glycoconjugates based on 1,5-diazabicyclo[3.3.0]octa-3,6-diene-2,8-dione ("bimane") as a central scaffold

The heteroaromatic fused diazabicyclic "bimane" ring system, discovered four decades ago, is endowed with remarkable chemical and photophysical properties. No carbohydrate derivatives of bimanes have, however, been described thus far. Here we report on the syntheses of a range of bimanes decorated with various glycosyl residues. Mono- and disaccharide residues were attached to syn- or anti-bimane central cores via thio-, disulfido- or selenoglycosidic linkages to obtain novel fluorescent or nonfluorescent glycoconjugates. Cu(I)-catalyzed cycloaddition of glycosyl azides to a bimane diethynyl derivative furnished further bivalent glycoconjugates with sugar residues linked to the central bimane core via 1,2,3-triazole rings. We have determined the crystal and molecular structures of several glycosylated and non-glycosylated bimanes and report fluorescence data for the new compounds.

A reaction-based near-infrared fluorescent probe that can visualize endogenous selenocysteine in vivo in tumor-bearing mice

Monitoring the fluctuations of endogenous selenocysteine (Sec) in vivo is of significant interest to understand the physiological roles of Sec and the mechanisms of Sec-relevant diseases. Herein, a new near-infrared fluorescent probe, Fsec-1, has been developed for the determination of endogenous Sec in living cells and in vivo. Fsec-1 exhibits large fluorescence enhancement (136-fold) and a remarkably large Stokes shift (195 nm) when reacted with Sec. With the advantages of high sensitivity (a detection limit of 10 nM), good selectivity and low cytotoxicity, Fsec-1 was able to recognize both exogenous and endogenous Sec in living cells. The probe was also successfully applied in visualizing both exogenous and endogenous Sec in living mice. Notably, endogenously generated Sec in living tumors xenografted in nude mice was selectively detected by our reaction-based NIR probe for the first time. These results indicated that our new probe could serve as an efficient tool in monitoring endogenous Sec in vivo and exploring the anticancer mechanism of selenium.