Unraveling Spatiotemporal Metabolic Perturbation of Amino Acids Associated with Ischemia-Reperfusion Injury by MALDI MS Imaging.

Various complex metabolic perturbations are involved in cerebral ischemia-reperfusion (I/R) injury. However, limited data have been reported on dynamic spatiotemporal metabolic perturbations of amino acids (AAs) in I/R injured rat brains. In this work, a combination of laser-assisted chemical transfer (LACT) and hexafluoroisopropanol (HFIP) was applied to the enhancement of on-tissue derivatization of AAs for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of their dynamic spatiotemporal changes during I/R injury.

The preparation of difluoromethylated indoles electrochemical oxidation under catalyst- and oxidant-free conditions.

A green and efficient electrochemical method for the preparation of difluoromethylated indoles has been developed. In this work, sodium difluoromethanesulfinate (HCFSONa) was used as the fluorinating reagent, and various indole derivatives with difluoromethylation at the C-2 position were obtained in moderate to good yields under catalyst- and oxidant-free conditions. Moreover, this C-2 difluoromethylation protocol is operationally simple, proceeds at room temperature, and can be easily scaled up.