Fluorination can dramatically improve the thermal and proteolytic stability of proteins and their enzymatic activity. Key to the impact of fluorination on protein properties is the hydrophobicity of fluorinated amino acids. We use molecular dynamics simulations, together with a new fixed-charge, atomistic force field, to quantify the changes in hydration free energy, ΔGHyd, for amino acids with alkyl side chains and with 1 to 6 -CH → -CF side chain substitutions. Fluorination changes ΔGHyd by -1.5 to +2 kcal mol-1, but the number of fluorines is a poor predictor of hydrophobicity. Changes in ΔGHyd reflect two main contributions: (i) fluorination alters side chain-water interactions; we identify a crossover point from hydrophilic to hydrophobic fluoromethyl groups which may be used to estimate the hydrophobicity of fluorinated alkyl side-chains; (ii) fluorination alters the number of backbone-water hydrogen bonds via changes in the relative side chain-backbone conformation. Our results offer a road map to mechanistically understand how fluorination alters hydrophobicity of (bio)polymers.
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http://dx.doi.org/10.1039/c8cp07025c | DOI Listing |
J Chromatogr A
January 2025
State Key Laboratory of Advanced Drug Delivery and Release Systems, and Medical Science and Technology Innovation Center, School of Pharmaceutical Sciences & Institute of Materia Medica, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China. Electronic address:
Considering the widespreadly use, large consumption, and serious environmental and health threats of phenylpyrazole insecticides (PPIs), development of a selective and sensitive method for accurate detection of their residuals in food samples is of great significance and challenging. Herein, depending on the hydrophobic and F-containing characteristics of PPIs, a novel fluorinated magnetic microporous organic network (FMMON) was designed and prepared for efficient and selective magnetic solid-phase extraction (MSPE) of two typical PPIs (fipronil and ethiprole) from milk and egg samples before the HPLC-UV determination. FMMON owned large specific surface area, multiple interaction sites, excellent magnetic separation performance and stability and exhibited good extraction and selectivity for fipronil and ethiprole through the specific F-F, hydrogen bonding, hydrophobic, and π-π interactions.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemical Engineering, University of Patras, Patras 26504, Greece.
Energy-efficient separation of light alkanes from alkenes is considered as one of the most important separations of the chemical industry today due to the high energy penalty associated with the applied conventional cryogenic technologies. This study introduces fluorine-doped activated carbon adsorbents, where elemental fluorine incorporation into the carbon matrix plays a unique role in achieving high ethane selectivity. This enhanced selectivity arises from specific interactions between surface-doped fluorine atoms and ethane molecules, coupled with porosity modulation.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
The power conversion efficiency (PCE) of perovskite solar cells is sensitive to their method of fabrication as well as the combination of materials in the perovskite layer. Air knife-assisted blade coating enables good quality perovskite films to be formed but the device efficiencies still tend to lag behind those fabricated using spin-coated perovskite layers. Herein we report the use of three 2,3,4,5,6-pentafluorophenylethylammonium halides (FEAX, where X = I, Br or Cl) as additives in nitrogen knife-assisted blade-coated methylammonium lead iodide (MAPbI) perovskite solar cells.
View Article and Find Full Text PDFJ Control Release
January 2025
National Engineering Research Center of Ophthalmology and Optometry, School of Biomedical Engineering, School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou 325027, China. Electronic address:
Current pharmacotherapy for DED is limited by a vicious inflammatory cycle in which reactive oxygen species (ROS) play a critical role. Additionally, topical eye drop therapy for DED often suffers from poor ocular availability due to multiple ocular surface barriers. Considering the key role of the ROS-NLRP3-IL-1β signaling axis in DED, in this investigation, fluorinated multifunctional polymer vesicles were developed for enhanced ocular surface penetration and synergistic DED therapy by combining ROS scavenging and immunomodulation.
View Article and Find Full Text PDFRSC Adv
January 2025
Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University Wenzhou 325035 Zhejiang China
Waterproof fatliquoring agents can transform leather from a hydrophilic state to a hydrophobic state in the wet process of leather production. However, traditional waterproof fatliquoring agents may cause environmental pollution. Fluorocarbons in fluorinated fatliquoring agents are difficult to degrade, and polyacrylic acid fatliquoring agents require chromium powder fixation.
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