A novel chiral stationary phase based on chitosan covalently bonded onto silica gels has been prepared and used for the separation of various alpha-amino acid enantiomers as well as alpha-hydroxycarboxylic acid enantiomers by chiral ligand-exchange chromatography with copper(II) as a complexing ion. The methanol content and copper(II) ion concentration in the eluent affected retentivity and enantioselectivity. Furthermore, a plausible chiral recognition mechanism for resolution of alpha-amino acids was proposed.
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http://dx.doi.org/10.1002/jssc.200600015 | DOI Listing |
Mini Rev Med Chem
January 2025
Department of Physiology and Pharmacology Vittorio Erspamer, Sapienza University of Rome, 00161, Rome, Italy.
Currently, the synthesis of bioactive sulfonamides using amino acid as a starting reagent has become an area of research interest in organic chemistry. Over the years, an amine-sulfonyl chloride reaction has been adopted as a common step in traditional sulfonamide synthetic methods. However, recent developments have shown amino acids to be better precursors than amines in the synthesis of sulfonamides.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China.
Lymphedema, a severe and complex inflammatory disease caused by lymphatic system insufficiency and impeded lymphatic drainage that causes an enormous physical and psychological burden on patients and may even lead to death, has long been a challenging issue in the medical field. Clinically, conventional approaches including surgical treatment and conservative treatment have been employed for lymphedema therapy, but their curative effect is still unsatisfactory because of high operational difficulty, high cost, and long-term reliance. In this study, a novel kind of piezoelectric microneedle driven by ultrasound (US) is proposed to regulate macrophage polarization and remodel the pathological inflammatory microenvironment in a noninvasive manner, thereby promoting lymphatic regeneration and improving lymphedema.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials and Shanghai Hongkong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
This study tackles the challenge of enantiodifferentiation of nitrile compounds, which is typically difficult to resolve using nuclear magnetic resonance (NMR) due to the significant distance between the chiral center and the nitrogen atom involved in molecular interactions. We have developed novel chiral F-labeled probes, each featuring two chiral centers, to exploit the "match-mismatch" effect, thereby enhancing enantiodiscrimination. This strategy effectively differentiates chiral analytes with quaternary chiral carbon centers as well as those with similar substituents at the chiral center.
View Article and Find Full Text PDFNano Lett
January 2025
NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
Metal nanocrystals synthesized in achiral environments usually exhibit no chiroptical effects. However, by placing nominally achiral nanocrystals 1.3 nm above gold films, we find giant chiroptical effects, reaching anisotropy factors as high as ≈ 0.
View Article and Find Full Text PDFAcc Chem Res
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen 361005, P. R. China.
ConspectusMolecular photoelectrocatalysis, which combines the merits of photocatalysis and organic electrosynthesis, including their green attributes and capacity to offer novel reactivity and selectivity, represents an emerging field in organic chemistry that addresses the growing demands for environmental sustainability and synthetic efficiency. This synergistic approach permits access to a wider range of redox potentials, facilitates redox transformations under gentler electrode potentials, and decreases the use of external harsh redox reagents. Despite these potential advantages, this area did not receive significant attention until 2019, when we and others reported the first examples of modern molecular photoelectrocatalysis.
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