The detection of hydrogen sulfide (H(2)S), a toxic gas and an important biological signaling molecule, has been a long-time challenge. Here we report genetically encoded fluorescent protein (FP)-based probes that can selectively detect H(2)S. By expanding the genetic codes of E. coli and mammalian cells, FP chromophores were modified with the sulfide-reactive azide functional group. These structurally modified chromophores were selectively reduced by H(2)S, resulting in sensitive fluorescence enhancement detectable by spectroscopic and microscopic techniques. Exploration of a circularly permuted FP led to an improved sensor with faster responses, and the feasibility of using such a genetically encoded probe to monitor H(2)S in living mammalian cells has also been demonstrated.

Peroxynitrite is a highly reactive molecule involved in cell signaling and pathological processes. We hereby report a novel genetically encoded probe, pnGFP, which can selectively sense peroxynitrite. A boronic acid moiety was site-specifically introduced into circularly permuted fluorescent proteins. By examining different protein templates followed with site-targeted random mutagenesis, we identified a selective peroxynitrite sensor, which is essentially unresponsive to other common cellular redox signaling molecules. The new probe has been genetically introduced into mammalian cells to image peroxynitrite at physiologically relevant concentrations.

A method for aliphatic C-H bond oxidation of oximes and hydrazones mediated by 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) has been developed, which enables the concise assembly of substituted isoxazole and pyrazole skeletons.

Pregabalin is an effective alternative for treatment of uraemic pruritus. Ondansetron has negligible effect on uremic pruritus and is expensive. A larger sample size may be needed to demonstrate the effect of ondansetron in uraemic pruritus.

An intriguing new Wacker-type oxidation of alkynes catalyzed by PdBr(2) and CuBr(2) is described, which opens an efficient access to 1,2-diketones using molecular oxygen. Under the optimized conditions, a variety of alkynes, including diarylalkynes, arylalkylalkynes, and dialkylalkynes, were compatible substrates in this transformation. The mechanism of this reaction was preliminarily investigated by control experiments.