Application of coupled oscillator theory to conformational analysis of glycosides with aromatic groups

Abstract

To confirm the range of application of the dipole–dipole interaction approximation in the coupled oscillator theory, the rotational strength of several p-nitrophenylglycosides (glucopyranoside, galactopyranoside, mannopyranoside, xylopyranoside, and fucopyranoside) and phenylglycoside (glucopyranoside) have been calculated with the Kirkwood–Tinoco equation. The orientations of the aromatic groups estimated by the above equation turn out to be in good agreement with those obtained from the semiempirical molecular orbital calculation (MNDO method) and molecular mechanics calculation (CHARMm). It is confirmed, therefore, that the Kirkwood–Tinoco equation is sufficiently applicable even when a chromophore is located relatively near a saturated group.