The thiamine-dependent enzyme （1R, 2S, 5S, 6S）-2-succinyl-5-enolpyruvyl-6-hydroxyl-3-cyclohexene-l-carboxylate （SEPHCHC） synthase, also known as MenD, catalyzes a Stetter-like reaction in the biosynthesis of vitam...The thiamine-dependent enzyme （1R, 2S, 5S, 6S）-2-succinyl-5-enolpyruvyl-6-hydroxyl-3-cyclohexene-l-carboxylate （SEPHCHC） synthase, also known as MenD, catalyzes a Stetter-like reaction in the biosynthesis of vitamin K. It is found to catalyze a novel reductive C-N bond ligation reaction between nitroarenes and et-ketoacids to form N-hydroxamates. This reaction likely pro- ceeds through an enzyme-mediated, slow two-electron reduction of the nitroalkanes to form a nitroso intermediate, which serves as the electrophilic acceptor of the ketoacid-derived acyl anion. The involvement of the nitroso intermediate is support- ed by the fact that similar N-hydroxamates are readily formed at a much higher rate when nitroso compounds replace the nitro substrates in the chemoenzymatic reactions. These results demonstrate that the thiamine-dependent enzyme is able to catalyze novel, nonnative reactions that may find new chemoenzymatic applications.展开更多
Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures c...Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.展开更多
文摘The thiamine-dependent enzyme （1R, 2S, 5S, 6S）-2-succinyl-5-enolpyruvyl-6-hydroxyl-3-cyclohexene-l-carboxylate （SEPHCHC） synthase, also known as MenD, catalyzes a Stetter-like reaction in the biosynthesis of vitamin K. It is found to catalyze a novel reductive C-N bond ligation reaction between nitroarenes and et-ketoacids to form N-hydroxamates. This reaction likely pro- ceeds through an enzyme-mediated, slow two-electron reduction of the nitroalkanes to form a nitroso intermediate, which serves as the electrophilic acceptor of the ketoacid-derived acyl anion. The involvement of the nitroso intermediate is support- ed by the fact that similar N-hydroxamates are readily formed at a much higher rate when nitroso compounds replace the nitro substrates in the chemoenzymatic reactions. These results demonstrate that the thiamine-dependent enzyme is able to catalyze novel, nonnative reactions that may find new chemoenzymatic applications.
基金supported by the National Natural Science Foundation of China(21875078 and 21975146)。
文摘Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.
