13C NMR spectral assignment of 5-hydroxy-1,5-imino-3-benzazocin-4,7,10-trione derivatives: The revised structure of renieramycin H

C-13 NMR assignments of the ABC ring model compounds of saframycin H with t he proposed structure were performed using a two-dimensional H-1 detected h eteronuclear multiple-bond correlation (HMBC) experiment. The structure of renieramycin H was reassigned with the revised structure.