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Updated: Aug 31, 2026

MALDI-Mass Spectrometric Imaging for the Investigation of Metabolites in Medicago truncatula Root Nodules
Published on: March 6, 2014
A direct method for assignment of absolute configurations in crown gall metabolites: the structure of nopaline
Abstract:
The absolute configurations of the crown gall tumor metabolite nopaline (1a) have been determined by a direct degradative method. Oxidation of nopaline with KMnO4 afforded (S)-arginine and (R)-glutamic acid. Separation of these two amino acids was accomplished easily and simultaneously with determination of chirality by chromatography on a reverse-phase column eluted with chiral eluent. The present technique can easily determine absolute configurations on submilligram quantities. In contrast, an attempted determination of absolute configuration by synthesis from (S)-arginine and chiral 2-chloropentanedioic acid was unsuccessful.
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