1H NMR Study of Conformation of Formyl-<scp>l</scp>-phenylalanyl-6-deoxy-6-amino-cyclomaltoheptaose That Has Excellent Ability of Chiral Recognition

Abstract

Abstract N-(N-Formyl-l-phenylalanyl)-6-deoxy-6-aminocyclomaltoheptaose (f-l-Phe-β-CD) is one of CD derivatives with excellent ability of chiral recognition. In order to make clear the mechanism of chiral recognition, the conformation of free f-l-Phe-β-CD has been studied by using 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. From the measurement of 1H homonuclear Overhauser enhancement on the rotating frame, it is concluded that f-l-Phe- residue of the f-l-Phe-β-CD is inserted into its cavity from the upside of primary hydroxyl groups of the macrocyclic ring. Analysis of 1H and 13C spectra of f-l-Phe-β-CD and model compounds of f-l-Phe- residue also support this conclusion. The macrocyclic ring is found to be distorted.