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A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles
Published on: December 23, 2016
Rigid duplex alpha-cyclodextrin reversibly connected with disulfide bonds. Synthesis and inclusion complexes
Lukás Kumprecht1, Milos Budesínský, Jirí Vondrásek
1Institute of Organic Chemistry and Biochemistry AS CR, v.v.i. Flemingovo nám. 2, 166 10 Praha 6, Czech Republic.
The Journal of Organic Chemistry
|December 31, 2008
Summary
A novel rigid duplex cyclodextrin was synthesized and demonstrated superior binding affinity for long-chain diols. This enhanced binding, driven by enthalpic factors, offers potential for advanced molecular recognition applications.
Area of Science:
- Supramolecular Chemistry
- Organic Synthesis
- Host-Guest Chemistry
Background:
- Cyclodextrins are cyclic oligosaccharides known for their ability to form inclusion complexes.
- Designing rigid cyclodextrin architectures can enhance binding selectivity and affinity.
- Disulfide-bridged cyclodextrin dimers represent a promising class of supramolecular hosts.
Purpose of the Study:
- To synthesize a rigid, doubly bridged alpha-cyclodextrin dimer.
- To investigate the binding properties of the synthesized duplex cyclodextrin with various guests.
- To elucidate the factors contributing to enhanced guest binding affinity.
Main Methods:
- Multi-step organic synthesis involving oxidative coupling.
- Structural characterization using Mass Spectrometry (MS), 2-D Nuclear Magnetic Resonance (NMR), and X-ray crystallography.
- Binding studies employing isothermal titration calorimetry (ITC).
- Computational analysis using Density Functional Theory (DFT-D) methods.
Main Results:
- Successful synthesis of a rigid duplex cyclodextrin (6) with a 73% overall yield.
- Duplex cyclodextrin 6 exhibits significantly enhanced binding affinity towards alpha,omega-alkanediols compared to singly bridged analogues.
- Binding constants reached up to 8.6 x 10^9 M^-1 for 1,14-tetradecanediol, with affinity increasing with alkyl chain length.
- Enhanced binding is primarily attributed to enthalpic contributions, stemming from dispersion interactions.
Conclusions:
- The rigid, doubly bridged duplex cyclodextrin architecture effectively enhances host-guest binding affinity.
- Thermodynamic control during synthesis favors the formation of the desired duplex structure.
- The findings highlight the potential of rationally designed cyclodextrin dimers for molecular recognition and host-guest chemistry applications.
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