1. High-Affinity Binding of Metallacarborane Cobalt Bis(dicarbollide) Anions to Cyclodextrins and Application to Membrane Translocation
- Author
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Barbara Begaj, Angelina Frank, Mohamed Nilam, Bohumír Grüner, Ali S. Mougharbel, Jan Nekvinda, Khaleel I. Assaf, Ulrich Kortz, Werner M. Nau, and Detlef Gabel
- Subjects
Anions ,Boron Compounds ,Models, Molecular ,Cyclodextrins ,Liposome ,Aqueous solution ,010405 organic chemistry ,Chemistry ,Lipid Bilayers ,Organic Chemistry ,chemistry.chemical_element ,Isothermal titration calorimetry ,Cobalt ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Membrane ,Liposomes ,Organometallic Compounds ,Thermodynamics ,Molecule ,Cyclic voltammetry ,Lipid bilayer - Abstract
Metallacarboranes are a class of inorganic boron clusters that have recently been recognized as biologically active compounds. Herein, we report on the host-guest complexation of several cobalt bis(1,2-dicarbollide) anions (COSANs) with cyclodextrins (CDs) in aqueous solution. The binding affinities reach micromolar values, which are among the highest known values for native CDs, and exceed those for neutral hydrophobic organic guest molecules. The entrapment of the COSANs inside the cavity of CDs was confirmed using NMR and UV-visible spectroscopy, mass spectrometry, cyclic voltammetry, and isothermal titration calorimetry. Complexation by CDs greatly influences the photophysical and electrochemical properties of COSANs. In combination with indicator displacement assays, a label-free fluorescence-based method was developed to allow real-time monitoring of the translocation of COSANs through lipid bilayer membranes.
- Published
- 2019
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