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.