Complete spectroscopic structural characterization of novobiocin, isonovobiocin, decarbamylnovobiocin, 2"-(O-carbamyl)novobiocin, and novobiocin-2",3"-carbonate

The rigorous structural characterization of novobiocin, is reported using mass spectrometric, infrared and nmr spectroscopic analysis. Complete nmr assignments are reported. Previous reports in the literature had left some quaternary carbon resonances unassigned. Isonovobiocin and decarbamylnovobiocin, although known in the literature for a number of years, have never been completely characterized. Mass spectrometric fragmentation pathways and complete H-1 and C-13 nmr assignments are reported for these congeners for the first time. The mass spectral fragmentation pathway and nmr assignments are also reported for 2 "-(O-carbamyl)novobiocin although the nmr assignments at lower field were reported previously. The structural characterization of novobiocin-2 ",3 "-carbonate observed in the Test Assay procedure used for Novobiocin is reported for the first time.