NMR Derivatives for Quantification of 2H and 13C - Enrichment of Human Glucuronide from Metabolic Tracers

Quantification of 2H and 13C enrichment distributions in human urinary glucuronide following ingestion of 2H2O and 13C gluconeogenic tracers was achieved by NMR spectroscopy of the 1,2-O-isopropylidene a-D-glucofuranurono-6,3-lactone and 5-O-acetyl-1,2-O-isopropylidene-a-D-glucofuranurono-6,3-lactone derivatives. The derivatization process is simple and can be applied to any glucuronide species. The derivatives are highly soluble in acetonitrile and generate well-resolved and narrow 2H and 13C NMR signals. The 1,2-O-isopropylidene-a-D-glucofuranurono-6,3-lactone derivative provided resolution of the six glucuronide 13C signals and numerous 13C isotopomer populations through one- and two-bond 13C-13C-coupling, while the 5-O-acetyl-1,2-Oisopropylidene-a-D-glucofuranurono-6,3-lactone derivative provided complete resolution
of the 2H NMR signals for the five glucuronide hydrogens. The isopropylidene
methyl signals were also resolved and provided an internal 2H enrichment standard following the acetonation of glucuronolactone with deuterated acetone.