Infection with Candida albicans can prove lethal in immuno-compromised patients. It is imperative to develop a vaccine against this common organism. The amphoteric derivatives of the mannan component of the Candida cell wall may present a prospective target for the development of such a vaccine; however, the radical processing by antigen-presenting cells of the immune system is not fully understood. In this work a set of tailor-made cationic and amphoteric derivatives of three different degrees of quaternization (DS 0.14-0.38) has been prepared by chemical modification of ultrasonically-treated mannan and three carboxymethylated mannan derivatives (DS 0.13-0.32). These were exposed to free-radical attack by OH, generated in situ by the Fenton reaction. Potential changes in composition, DS, and molar mass distribution due to free-radical degradation were monitored by elemental analysis, NMR and FTIR spectroscopies, and size exclusion chromatography. A protective effect of quaternization against OH degradation was found. Non-isothermal thermogravimetric analysis found that the thermal stability of this mannan was also improved by chemical modification.
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http://dx.doi.org/10.1016/j.carbpol.2018.11.101 | DOI Listing |
RSC Med Chem
October 2024
Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences 200241 Shanghai China
Bacterial infections pose a threat to human and animal health, and the formation of biofilm exacerbates the microbial threat. New antimicrobial agents to address this challenge are much needed. In this study, several new amphoteric compounds derived from the natural product coumarin were designed and synthesized by mimicking the structure and function of antimicrobial peptides.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
Lignin, a biomass-derived material containing chromophores, possesses the potential to serve as a versatile organic ultraviolet (UV) light screening agent. By employing quantum chemical computation techniques, an amphoteric deep eutectic solvent (DES) based on sulfamic acid was purposefully designed and engineered to create a solvent system tailored for the nanoparticle formation and functionalization of lignin. As confirmed by experimental evidence, the size of the modified lignin nanoparticles (LNPs) varies from 168.
View Article and Find Full Text PDFNat Commun
January 2025
School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan, China.
[n]Peri-acenes ([n]PA) have attracted great interest as promising candidates for nanoelectronics and spintronics. However, the synthesis of large [n]PA (n > 4) is extremely challenging due to their intrinsic open-shell radical character and high reactivity. Herein, we report the successful synthesis and isolation of a derivative (1) of peri-hexacene in crystalline form.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin, 300350, China.
High-spin polycyclic hydrocarbons (PHs) hold significant potential in organic spintronics and organic magnets. However, their synthesis is very challenging due to their extremely high reactivity. Herein, we report the successful synthesis and isolation of a kinetically blocked derivative (1) of dianthraceno[2,3-a : 3',2'-h]-s-indacene, which represents a rare persistent triplet diradical of a Kekulé PH.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Department of Chemistry, National University of, Singapore, 3 Science Drive 3, 117543, Singapore.
We report a robust strategy for tuning the electronic structure and chemical stability of π-conjugated polycyclic hydrocarbons (PHs). By fusing two cyclopentadienyl rings in the peri-tetracene bay regions, we introduce antiaromatic character into the π-system, leading to unique photophysical and electronic properties. A stable mesityl-substituted dicyclopenta-peri-tetracene derivative was synthesized through stepwise formylation/intramolecular cyclization at the bay regions of the dihydro peri-tetracene precursor, followed by oxidative dehydrogenation.
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