ABSTRACT
The glucosylation of isatin-3-oxime (1) was monitored by in situ 2D 1H-13C inverse correlated gradient assisted NMR spectroscopy in plant cell suspension cultures of Rauvolfia serpentina without labelling. The applied high magnetic field of 800 MHz allowed measurements within 20 min at concentrations of 1 of 5.76 mM. Complete glucosylation of 1 occurs inside the cells within 72 hours. During this time isatin-3-oxime-glucoside (2) accumulates without further metabolism.
Subject(s)
Glucosides/isolation & purification , Isatin/isolation & purification , Rauwolfia/chemistry , Carbon/chemistry , Catalysis , Chromatography, High Pressure Liquid , Culture Techniques , Glucosides/chemistry , Glycosylation , Hydrogen/chemistry , Isatin/analogs & derivatives , Isatin/chemistry , Mass Spectrometry , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plants, Medicinal/chemistry , Plants, Medicinal/metabolism , Rauwolfia/metabolism , beta-Glucosidase/metabolismABSTRACT
Prajmaline, the semisynthetic propyl derivative of ajmaline, shows a much better bioavailability when compared with the Rauvolfia alkaloid ajmaline. Early NMR and IR-studies, fluorescence spectroscopic investigations and extraction experiments combined with ion-pair chromatography proved the thesis of a tautomeric equilibrium between an aldehyde-amine and a quaternary carbinol-ammonium component. The aim of this study was to confirm this thesis by HPLC-separation and by structure-determination of both tautomeric compounds.
