ELECTRIC-FIELD THEORY APPLIED TO THE H-1 AND C-13 NUCLEAR MAGNETIC-RESONANCE SPECTRA OF CARBOHYDRATES

1H and 13C NMR spectra of D-galacturonic and D-glucuronic acids have been measured and assignments made. Chemical shifts induced by variation of pH and addition of Ca2+ ion have been considered, quantitatively for pH changes, in the context of electric field theory. The field gradient contribution to that theory has been reconsidered in more detail, α and β anomers were treated separately, with crystallographic data of homologues used to provide bond angles and distances. The equilibrium constants for complexes with calcium ion were measured and compared with previous values. © 1979 American Chemical Society.