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Mutual induced fit in cyclodextrin-rocuronium complexes.

Alan Cooper·Margaret Nutley·Elizabeth J MacLean·Ken Cameron·Lee Fielding·Jordi Mestres·Ronald Palin
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Abstract

The binding of rocuronium bromide to 6-perdeoxy-6-per(4-carboxyphenyl)thio-gamma-cyclodextrin sodium salt, displays biphasic behaviour characteristic of the formation of a binary and 2 : 1 ternary guest-host complex in aqueous solution. Thermodynamic and structural data on this sequential complexation process can be rationalised within a single model involving switching of the conformational equilibria of both the rocuronium bromide and cyclodextrin molecules. Isothermal titration calorimetry (ITC), NMR and fluorescence experiments in solution, together with X-ray crystallography and molecular modelling, suggest that in order to induce encapsulation both rocuronium bromide and the modified cyclodextrin undergo conformational changes. Ring A of rocuronium bromide 'switches' from the more sterically encumbered chair to the sterically less demanding twist-boat, whilst the modified cyclodextrin "opens" its cavity to allow the steroid to enter. The recognition and mutual induced fit between cyclodextrin and steroid represents a classic example of dynamic host-guest chemistry.

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AndrostanolsCalorimetryCrystallographyCyclodextrinsMagnetic Resonance SpectroscopyNeuromuscular Blocking AgentsRocuroniumSpectrometry, FluorescenceSpectrophotometry, UltravioletJournal Article

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Alan Cooper, Margaret Nutley, Elizabeth J MacLean, Ken Cameron, Lee Fielding, Jordi Mestres, Ronald Palin. 2005-03-23. Mutual induced fit in cyclodextrin-rocuronium complexes.. https://doi.org/10.1039/b415903a

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