Saccharide recognition-induced transformation of pyridine-pyridone alternate oligomers from self-dimer to helical complex.
Co-oligomers involving (1H)-4-pyridone and 4-alkoxypyridine rings were studied, and it was found that their supramolecular transformation was caused by saccharide recognition. In the co-oligomers, pyridone and pyridine rings are alternately linked at their 2,6-position with an acetylene bond. The pyridine rings behave as a hydrogen bonding acceptor, and the pyridone rings and tautomerized 4-pyridinol work as a donor. Pyridine-pyridone-pyridine 3-mer was found to self-dimerize on the basis of vapor pressure osmometry in CHCl(3), and the association constant was obtained as 2.3 x 10(3) M(-1) by (1)H NMR titration. Longer 5-, 7-, 9-, and 11-mer oligomers showed considerable broadening and anisotropy in the (1)H NMR spectra due to self-association. These longer oligomers recognized octyl beta-D-glucopyranoside and changed their form into a chiral helical complex, showing characteristic circular dichroism.
Abe
Hajime
H
Graduate School of Pharmaceutical Sciences, University of Toyama, Toyama, Japan. abeh@pha.u-toyama.ac.jp
Machiguchi
Hiroshi
H
Matsumoto
Shinya
S
Inouye
Masahiko
M
D002241:Carbohydrates / Q000737:chemistry*; D019281:Dimerization; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D011728:Pyridones / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D002241:Carbohydrates; D011108:Polymers; D011725:Pyridines; D011728:Pyridones; C023666:pyridine