A dozen of homoditopic cations, possessing different spacer lengths and rigidities, as well as sizes, shapes, and charges of terminal groups, were synthesized as candidate gemini guests for the complexation of p-sulfonatocalix[4]arenes (SC4A). The 12 gemini guests are divided into five species according to the different terminal groups: imidazolium (G1-G3), pyridinium (G4-G6), quinolinium (G7), viologen (G8-G11), and 1,4-diazabicyclo[2.2.2]octane (DBO, G12). Their binding structures and stoichiometries with SC4A were examined by NMR spectroscopy, which is helpful to construct diverse highly ordered assemblies. The obtained results show that the length of the linkers, as well as the charge numbers on the end groups have a pronounced effect on the binding stoichiometry, whereas the size and shape of the terminal groups have no significant influence. Furthermore, both the stability constants and thermodynamic parameters of SC4A with the terminal subunits were determined by the isothermal titration calorimetry experiments, which are valuable to understand the binding behavior, giving quantitatively deep insight.
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http://dx.doi.org/10.1021/jp312744d | DOI Listing |
Soft Matter
August 2024
Department of Chemistry, School of Science, Tokyo Institute of Technology, Meguro-ku, 2-12-1 Ookayama, Tokyo 152-8551, Japan.
Herein, we report a straightforward synthesis of azaylide-based gemini amphiphiles using bis(diphenylphosphino)alkanes the Staudinger reaction. The prepared gemini amphiphiles exhibited an even-odd effect in their self-assembly behavior depending on the length of the alkyl linkers. Furthermore, the assembled micelles had high host capability toward hydrophobic guests in water.
View Article and Find Full Text PDFLancet
October 2023
Retina Consultants of Texas, Houston, TX, USA; Blanton Eye Institute, Houston, TX, USA; Houston Methodist Hospital, Houston, TX, USA. Electronic address:
Background: Geographic atrophy is a leading cause of progressive, irreversible vision loss. The objectives of OAKS and DERBY were to assess the efficacy and safety of pegcetacoplan compared with sham treatment in patients with geographic atrophy.
Methods: OAKS and DERBY were two 24-month, multicentre, randomised, double-masked, sham-controlled, phase 3 studies, in which patients aged 60 years and older with geographic atrophy secondary to age-related macular degeneration were enrolled at 110 clinical sites and 122 clinical sites worldwide, respectively.
Bioconjug Chem
March 2023
Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.
Dynamic covalent poly(disulfide)-based cross-linked nanoaggregates, termed nanonetworks (NNs), endowed with pH- and redox-responsive degradation features have been fabricated for stable noncovalent encapsulation and triggered cargo release in a controlled fashion. A bioderived lipoic acid-based Gemini surfactant-like amphiphilic molecule was synthesized for the preparation of nanoaggregates. It self-assembles by a entropy-driven self-assembly process in aqueous milieu.
View Article and Find Full Text PDFSince biocatalysts manoeuvre most of the physiological activities in living organisms and exhibit extreme selectivity and specificity, their use to trigger physicochemical change in polymeric architectures has been successfully used for targeted drug delivery. Our major interest is to develop lipase responsive nanoscale delivery systems from bio-compatible and biodegradable building blocks. Herein, we report the synthesis of four novel non-ionic Gemini amphiphiles using a chemo-enzymatic approach.
View Article and Find Full Text PDFRSC Adv
January 2022
Chemistry Department, Kuwait University P.O. Box 5969, Safat 13060 Kuwait +965-2481-6482 +965-2498-554.
Herein, we report a methodology for constructing mechanically self-locked molecules (MSMs) through the efficient intramolecular copper(i)-catalyzed alkyne-azide cycloaddition (CuAAC) of self-threaded A1/A2-azido-propargyl-difunctionalized pillar[5]arenes. The obtained monomeric "[1]catenane" and dimeric "-catenane" were isolated and fully characterized using mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and X-ray crystallography. Upon investigation by H NMR spectroscopy in chloroform, the observed motion for the threaded ring in the [1]catenane was reversibly controlled by the temperature, as demonstrated by variable-temperature H NMR studies.
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