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A kinetic study on the reactions of the cumyloxyl radical (CumO) with N-Boc-protected amino acids in the presence of the strong organic base DBU has been carried out. COH deprotonation increases the electron density at the α-C-H bonds activating these bonds toward HAT to the electrophilic CumO strongly influencing the intramolecular selectivity. The implications of these results are discussed in the framework of HAT-based aliphatic C-H bond functionalization of amino acids and peptides.
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http://dx.doi.org/10.1021/acs.orglett.7b03948 | DOI Listing |
J Am Chem Soc
September 2025
Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.
Genetic code expansion (GCE) technology has primarily been devoted to the introduction of noncanonical amino acids (ncAAs) into ribosomally synthesized proteins or peptides. Its potential for modifying nonribosomal natural products remains unexplored. In this study, we introduce a novel strategy that integrates GCE with the directed evolution of cyclodipeptide synthase (CDPS) to engineer a new class of CDPSs capable of biosynthesizing cyclodipeptides containing ncAAs.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
September 2025
Second Institute of Oceanography, Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources, Hangzhou 310018, PR China.
A Gram-staining-negative, non-motile, aerobic, rod-shaped bacterium, designated 14752, was isolated from a saline lake in Xinjiang Uygur Autonomous Region, China. The strain was subjected to a taxonomic study using a polyphasic approach. Strain 14752 was able to grow at 4-40 ℃ (optimum 28 ℃), pH 6.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240.
Major depressive disorder affects millions worldwide, yet current treatments require prolonged administration. In contrast, ketamine produces rapid antidepressant effects by blocking spontaneous N-Methyl-D-Aspartate (NMDA) receptor signaling, which lifts the suppression of protein synthesis and triggers homeostatic synaptic plasticity. Here, we identify a parallel signaling pathway involving metabotropic glutamate receptor 5 (mGluR5) that promotes rapid antidepressant-like effects.
View Article and Find Full Text PDFLasers Med Sci
September 2025
Department of Otolaryngology Head and Neck Surgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, 71 Hexi Street, Nanjing 210019, Jiangsu, China.
To evaluated the efficacy of photodynamic therapy (PDT) in improving laryngeal mucosal wound scar healing in vivo and investigated its underlying mechanisms. Laryngeal mucosal wounds were induced in Sprague-Dawley rats. Two weeks post-injury, PDT was administered via intraperitoneal injection of 100 mg/kg 5-aminolevulinic acid (5-ALA) and 635-nm red laser irradiation at varying energy doses (15, 30, and 45 J/cm²).
View Article and Find Full Text PDFAmino Acids
September 2025
Colorectal Research Center, Iran University of Medical Sciences, Tehran, 1445613131, Iran.
Anal fissure causes pain and bleeding during or after bowel movements, significantly impacting individuals' quality of life. Current treatments aim to interrupt this cycle but have associated risks and limitations. The emergence of arginine, crucial for protein creation and nitric oxide (NO) production, presents an intriguing therapeutic avenue by the impact on reducing anal sphincter pressure and enhancing anoderm blood flow, due to its roles in vasodilation, anti-inflammatory responses, and collagen synthesis, which can promote wound healing and highlighting its potential as an alternative therapy.
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