Wang, Y. and I.J. Dmochowski, Cucurbituril is an ultrasensitive (129)Xe NMR contrast agent. Chem Commun (Camb), 2015. 51(43): p. 8982-5.
A lack of molecular contrast agents has slowed the application of ultrasensitive hyperpolarized (129)Xe NMR methods. Here, we report that commercially available cucurbituril (CB) undergoes rapid xenon exchange kinetics at 300 K, and is detectable by Hyper-CEST NMR at 1.8 pM in PBS and at 1 muM in human plasma where many molecules, including polyamines, can compete with xenon for CB binding.