Supramolecular Interaction Between Cucurbit[8]uril and the Quinolone Antibiotic Ofloxacin

Abstract

The host–guest inclusion complex of cucurbit[8]uril (Q[8]) and ofloxacin (OFLX) has been prepared and characterised by means of 1H NMR spectroscopy, MALDI-TOF mass spectrometry, isothermal titration calorimetry (ITC), fluorescence spectroscopy, and UV-vis absorption spectroscopy. The findings demonstrated that a host–guest inclusion complex could be formed through an encapsulation of the methylmorpholine and piperazine rings in OFLX. ITC results indicated that the formation of this inclusion complex (1:1 molar ratio) was primarily dependent on enthalpy and entropy changes. In addition, the release of OFLX from the inclusion complex was increased under acidic conditions.