- Enantioselective Synthesis and Application of Small and Environmentally Sensitive Fluorescent Amino Acids for Probing Biological Interactions
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Environmentally sensitive fluorescent amino acids (FlAAs) have been used extensively to probe biological interactions. However, most of these amino acids are large and do not resemble amino acid side chains. Here, we report the enantioselective synthesis of two small and environmentally sensitive fluorescent amino acids bearing 7-dialkylaminocoumarin side chains by alkylation of a Ni(II) glycine Schiff base complex. These amino acids exhibit a large increase in fluorescence as environment polarity decreases. One of these FLAAs was incorporated into a highly active analog of the cyclic lipopeptide antibiotic paenibacterin by Fmoc solid-phase peptide synthesis via a new and very efficient route. This peptide was used to probe the interaction of the antibiotic with model liposomes, lipopolysaccharides, and live bacteria.
- Noden, Michael,Taylor, Scott D.
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p. 11407 - 11418
(2021/09/02)
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- Azetidine-Containing Heterospirocycles Enhance the Performance of Fluorophores
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Fluorescent dyes are extensively utilized in various fluorescence imaging techniques. However, many existing modification strategies could not balance the performance (such as brightness, photostability, water solubility, and permeability) of fluorophores. Herein we report a general strategy to enhance the performance of donor-acceptor-type fluorophores by introducing azetidine-containing heterospirocycles to the commonly used fluorophore scaffolds. Such a strategy turned out to be a general way to develop high-quality fluorophores.
- Zhou, Junliang,Lin, Xianfeng,Ji, Xin,Xu, Shuang,Liu, Chang,Dong, Xiaochun,Zhao, Weili,Zhao, Weili
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supporting information
p. 4413 - 4417
(2020/06/05)
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- A General Strategy to Enhance Donor-Acceptor Molecules Using Solvent-Excluding Substituents
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While organic donor-acceptor (D-A) molecules are widely employed in multiple areas, the application of more D-A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent-dependent mechanisms of excited-state quenching through addition of a β-carbonyl-based polar substituent. The results reveal a mechanism wherein the β-carbonyl substituent creates a structural buffer between the donor and the surrounding solvent. Through computational and experimental analyses, it is demonstrated that the β-carbonyl simultaneously attenuates two distinct solvent-dependent quenching mechanisms. Using the β-carbonyl substituent, improvements in the photophysical properties of commonly used D-A fluorophores and their enhanced performance in biological imaging are shown.
- Asbury, John B.,Hoelzel, Conner A.,Hu, Hang,Jung, Kwan Ho,Karim, Basel A.,Li, Xiaosong,Liu, Yu,Munson, Kyle T.,Wolstenholme, Charles H.,Yennawar, Hemant P.,Zhang, Han,Zhang, Xin
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supporting information
p. 4785 - 4792
(2020/02/11)
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- BENZOPYRANE AND IMIDAZOLE DERIVATIVES USEFUL FOR THE STABILIZATION OF AMYLOIDOGENIC IMMUNOGLOBULIN LIGHT CHAINS
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In immunoglobulin light chain amyloidosis (AL), the unique antibody light chain (LC) protein that is secreted by monoclonal plasma cells in each patient misfolds and/or aggregates, a process leading to organ degeneration. For treating AL patients, such as those with substantial cardiac involvement who have difficulty tolerating existing chemotherapy regimens, provided herein are small molecule compounds of Formula Ia, Formula Ib, and Formula II that are kinetic stabilizers of the native dimeric structure of full-length LCs, which compounds can slow or stop the amyloidogenicity cascade at its origin.
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Paragraph 00105; 00359
(2020/10/19)
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