No abstract

A near-infrared (NIR) and water-soluble probe was synthesized and studied for the detection of Cys/Hcy in aqueous solution, living cells and mice. The probe was composed of cyanine derivative as the NIR fluorescent reporting unit and pyrimidiny-thioether moiety as the Cys/Hcy responsive unit. Treatment with Cys/Hcy induced the formation of sulfur-substituted products, then intramolecular rearrangement reaction would occur to produce amino-substituted products and resulting in enhanced red fluorescence emissions. It could be applied to sense Cys/Hcy both in solution with the detection limit of 0.17 μM (or 0.32 μM) and in living cells. Cell imaging experiments proved that such a probe exhibited good cell penetration. In addition, the probe could detect Cys/Hcy in live mice with strong turn-on fluorescent response.

A series of novel quinoxaline derivatives were synthesized and evaluated for their antiproliferative activity in three human cancer cell lines. Compound 12 exhibited the most potent antiproliferative activity with IC50 in the range of 0.19–0.51 μM. The compound inhibited tubulin polymerization and disrupted the microtubule network, leading to G2/M phase arrest. Furthermore, compound 12 induced ROS production and malfunction of mitochondrial membrane potential. Compound 12 led to cancer cells apoptosis in a dose‐dependent manner. Western blot analysis showed that compound 12 induced up‐regulation of p21 and affected the expression of cell cycle‐related proteins. The binding mode was also probed by molecular docking.

Hypochlorousa cid (HOCl), one of the reactive oxygen species( ROS), is highly reactive and short-lived. It is ac hallenge to dynamic monitorH OCl activity in living systems. Hence, we synthesized an ew fluoresce nt probe RF1 based on protection of the hydroxyl group by N,N-dimethylthiocarbamate recognition group, which reached al ow fluorescence background signal and highly sensitivep roperty.O na ccount of the electrophilica ddition of Cl + to the sul-fide of thiocarbamate moiety,p robe RF1 was converted to resorufin and triggered emitting bright. RF1 showed not only the highlys ensitive and selective response to HOCl in vitro, but also can be applied in environmental water samples and detected HOCl by test strips. Besides, the ability of RF1 monitoring HOCl in HeLa cells by exogenous simulation and tracingn ative HOCl in macrophages cells were also explored.[a] Dr.