Nuclear magnetic resonance spectroscopic study of the inclusion complex of (R)-tedizolid with HDAS-β-CD, β-CD, and γ-cyclodextrin in aqueous solution

NMR spectroscopy is used to investigate the host-guest complexation of (R)-tedizolid, such as tedizolid with the hydroxymethyl substituent at the C5 position of the Oxazolidinone ring ((R)-TED) or tedizolid with 5-methyl dihydrogen phosphate ((R)-TED-PO₄) with heptakis-(2,3-diacetyl-6-sulfo)-β-cyclodextrin (HDAS-β-CD), β-CD and γ-CD, in particular to obtain information about the mode and strength of the guest complexation into the hydrophobic cavity of the host. The complex stoichiometries of 1:1 (host:guest) and 1:2 were detected in millimolar concentrations for HDAS-β-CD and γ-CD with TED-PO₄ complexes, respectively. In the meantime, the mixed of complexes with stoichiometries of 1:1 and 2:1 were found for β-CD with both TED and TED-PO₄, however the 1:1 complex had a significant advantage.The binding mode was proposed. The estimated binding constants K_a of the complexes of TED or TED-PO₄ with CDs differ significantly in the order HDAS-β-CD<<β-CD<<γ-CD.