Supramolecular Encapsulation of Vitamin B6 by Macrocyclic Nanocontainer Cucurbit[7]uril.

A pharmaceutically and biologically relevant molecule, pyridoxine hydrochloride (vitamin B₆), was encapsulated inside the cavity of a molecular container, cucurbit[7]uril (CB[7]), in aqueous solution. The CB[7] based “nanocapsule” of vitamin B₆ has been investigated for the first time, via ¹H NMR and UV-visible spectroscopic titrations (including Job’s plot) and ab initio molecular modeling. The results have demonstrated that vitamin B₆ forms stable host-guest complexes within CB[7] in 1 : 1 stoichiometry, with a binding affinity of (4.0±0.5)×¹⁰³ M⁻¹. Such a nanocapsule could potentially find application in vitamin B₆ formulation for the purpose of enhancing the stability, absorption, and delivery of this important vitamin. [ABSTRACT FROM AUTHOR]