Nonplanar Macrocycle Consisting of Four Pyridine and Phenol Units Connected with Acetylene Bonds Displaying Preferential Binding to Maltoside over Monosaccharides

A nonplanar macrocycle consisting of four pyridine–acetylene–phenol units was developed as a host for saccharide guest molecules. The macrocycle was found to strongly associate with a lipophilic maltose derivative, with an association constant of 10⁷ M^–1, over monosaccharide derivatives, for which much smaller association constants were determined, ranging from 10³ M^–1 to 10⁴ M^–1. The macrocycle was found to adopt a boat-like conformation, encapsulating β-d-maltoside in a twisted manner through approximately seven intermolecular hydrogen bonds.