Molecular, crystal and solution structure of a beta-cyclodextrin complex with the bromide salt of 2-(3-dimethylaminopropyl)tricyclo[3.3.1.1(3,7)]decan-2-ol, a potent antimicrobial drug

The pharmacological properties of a cyclomaltoheptaose (beta-cyclodextrin) series of adamantane-group-bearing compounds that exhibit potent antibacter ial activity have been studied, both isolated and in complex with beta-cycl odextrins (beta CDs). In this work, the structure of the bromide salt of 2- (3-dimethylaminopropyl)-tricyclo[3.3.1.1(3.7)]decan-2-ol (ADM-10) complexed with beta CD and ten water molecules was studied in the solid state by X-r ay crystallography and in solution by NMR spectroscopy. X-ray crystallograp hic studies of the complex were performed both at room and cryogenic temper atures. The long aliphatic chain of ADM-10 adopts a single conformation at low temperature in contrast to what is observed at room temperature, where two side chain conformations are seen. Both NMR and X-ray crystallography s tudies indicate that the adamantane moiety of ADM-10 is buried in the beta CB cavity. Chemical shifts in NMR experiments can be explained on the basis of the crystal structure of the complex. (C) 1999 Elsevier Science Ltd. Al l rights reserved.