Elucidating dissociation activation energies in host–guest assemblies featuring fast exchange dynamics

Abstract

GEST-NMR is utilized for quantifying the dissociation activation energy (Ea,out) in host-guest systems featuring fast dissociation dynamics.

Fast Ion-Chelate Dissociation Rate for In Vivo MRI of Labile Zinc with Frequency-Specific Encodability

“…The chemical shift offset (Δω) between two exchanging pools of spins is at the core of any designed CEST agent and thus, for 19 F-CEST-based studies. ,− This is mainly due to the fact that a larger Δω results in a reduced direct saturation effect, allowing the use of strong saturation powers for an enhanced CEST effect. Moreover, a larger Δω allows the use of CEST agents that are applicable under a faster exchange regime (fulfilling the condition Δω > k ex ) and, therefore, are detectable at much lower concentrations. , Thus, as a first step in our design, three putative fluorinated derivatives of DPA were synthesized based on the common use of a DPA backbone in both fluorescent- ,, and MRI- , responsive probes developed for imaging labile Zn 2+ under physiological conditions.…”

Rapid analytical CEST spectroscopy of competitive host–guest interactions using spatial parallelization with a combined approach of variable flip angle, keyhole and averaging (CAVKA)

“…Conditions should be reconsidered to resemble those of the case of pillar [5]arenes. 3 It has never been investigated in detail if Xe might only shortly reside at the portals of CB7 (an effect that is actually known for cations 4 ).…”

“…Saturation transfer between exchange-connected spin pools transfers information from a dilute pool (B) onto an abundant pool (A) and detects how a perturbation of B accumulates in A. 3,4 Hyperpolarization of a transiently bound guest as in the Hyper-CEST approach 5 provides a huge sensitivity boost. This yields access to various supramolecular systems down to nanomolar concentrations.…”

“…Some saturation transfer techniques even require signal averaging for unlocalized spectra. 4,15 Acceleration approaches are therefore highly desired.…”

Simultaneous analyte indicator binding assay (SBA) for the monitoring of reversible host–guest complexation kinetics

“…21 Besides, association rates play also a significant role in drug research due to their capability to modulate the onset of biological response. 22 In contrast to the large amount of biomedical related kinetic measurements, much less attention has been paid to the dynamics of host-guest complex formation of simple macrocyclic compounds [23][24][25][26] despite the increasing need for estimating the equilibration time or response time after an external stimulus, as are crucial for fine tuning in sensing, materials and drug delivery applications. 27 So far, rate constants of reversible encapsulation processes have been mainly studied via direct-binding assays (kinDBA) for environment-sensitive fluorescent guests by monitoring the alteration of their emission intensity upon host-receptor binding.…”