title: 13C isotope effects on 1H chemical shifts: NMR spectral analysis of 13C-labelled D-glucose and some 13C-labelled amino acids.
abstract: The one- and two-bond (13)C isotope shifts, typically -1.5 to -2.5 ppb and -0.7 ppb respectively, in non-cyclic aliphatic systems and up to -4.4 ppb and -1.0 ppb in glucose cause effects that need to be taken into account in the adaptive NMR spectral library-based quantification of the isotopomer mixtures. In this work, NMR spectral analyses of some (13)C-labelled amino acids, D-glucose and other small compounds were performed in order to obtain rules for prediction of the (13)C isotope effects on (1)H chemical shifts. It is proposed that using the additivity rules, the isotope effects can be predicted with a sufficient accuracy for amino acid isotopomer applications. For glucose the effects were found strongly non-additive. The complete spectral analysis of fully (13)C-labelled D-glucose made it also possible to assign the exocyclic proton signals of the glucose.
authors.affiliation: Laboratory of Chemistry, Department of Biosciences, University of Kuopio, Finland. Mika.Tiainen@uef.fi
authors.forename: Mika
authors.initials: M
authors.lastname: Tiainen
authors.forename: Hannu
authors.initials: H
authors.lastname: Maaheimo
authors.forename: Pasi
authors.initials: P
authors.lastname: Soininen
authors.forename: Reino
authors.initials: R
authors.lastname: Laatikainen
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000737:chemistry; D000409:Alanine / Q000032:analysis / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D001554:Benzene / Q000032:analysis / Q000737:chemistry; D002247:Carbon Isotopes / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D007930:Leucine / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D011522:Protons
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D011522:Protons; D007930:Leucine; D005947:Glucose; D001554:Benzene; D000409:Alanine; D019342:Acetic Acid