A mild and efficient protocol for C4-H sulfonylation of 1-naphthylamine derivatives with sodium sulfinates has been described. This C4 sulfonylation proceeded smoothly at room temperature under Ru/Cu photoredox catalysis or Cu/Ag cocatalysis and could tolerate various functional groups. In addition, control experiments suggested that this C4-H sulfonylation reaction might proceed via a single-electron-transfer process.

Bile acids (BAs) are a type of gut microbiota–host cometabolites with abundant structural diversity, and they play critical roles in maintaining host–microbiota homeostasis. In this study, we developed a new N-(4-aminomethylphenyl) pyridinium (AMPP) derivatization-assisted alternating dual-collision energy scanning mass spectrometry (AMPP-dual-CE MS) method for the profiling of BAs derived from host–gut microbiota cometabolism in mice. Using the proposed method, we discovered two new types of amino acid conjugations (alanine conjugation and proline conjugation) and acetyl conjugation with host BAs, for the first time, from mouse intestine contents and feces. Additionally, we also determined and identified nine new leucine- and phenylalanine-conjugated BAs. These findings broaden our knowledge of the composition of the BA pool and provide insight into the mechanism of host–gut microbiota cometabolism of BAs.

Although chemoselective labeling strategies show great potential in in-depth description of metabolomics, the associated time and expense limit applications in high-throughput and routine analysis. We report a fast and effective chemoselective labeling strategy based on multifunctionalized monolithic probes. A rapid pH-responsive boronate ester reaction was employed to immobilize and release probe molecules from substrate in 5 min. The mesoporous surface and hierarchically porous channels of the substrate allowed for accelerated labeling reactions. Moreover, the discernible boron beacons allowed for recognition of labeled metabolites with no need for expensive isotopic encoding. This new strategy has been successfully used for submetabolome analysis of yeast cells, serum, and faeces samples, with improved sensitivity for short chain fatty acids up to 1 600 times compared with non-labeled liquid chromatography-mass spectrometry (LC-MS) methods.

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Mediator complex subunit 16 (MED16) is a component of the mediator complex and functions as a coactivator in transcriptional events at almost all RNA polymerase II–dependent genes. In this study, we report that the expression of MED16 is markedly decreased in papillary thyroid cancer (PTC) tumors compared with normal thyroid tissues. In vitro, MED16 overexpression in PTC cells significantly inhibited cell migration, enhanced sodium/iodide symporter (NIS) expression and iodine uptake, and decreased resistance to radioactive 131I (RAI). Conversely, PTC cells in which MED16 had been further knocked down (MED16KD) exhibited enhanced cell migration, epithelial-mesenchymal transition (EMT), and RAI resistance, accompanied by decreased sodium/iodide symporter (NIS) levels. Moreover, cell signaling through transforming growth factor β (TGF-β) was highly activated after the MED16 knockdown. Similar results were obtained in MED12KD PTC cells, and a co-immunoprecipitation experiment verified interactions between MED16 and MED12 and MED16 and TGF-βR2. Of note, the application of LY2157299, a potent inhibitor of TGF-β signaling, significantly attenuated MED16KD-induced RAI resistance both in vitro and in vivo. In conclusion, our findings indicate that MED16 reduction in PTC contributes to tumor progression and RAI resistance via the activation of the TGF-β pathway.