Reinvestigation of the Branimycin Stereochemistry at Position 17‑C

A conformational study of branimycin
was performed using single-crystal
X-ray crystallography to characterize the solid-state form, while
a combination of NMR spectroscopy and molecular modeling was employed
to gain information about the solution structure. Comparison of the
crystal structure with its solution counterpart showed no significant
differences in conformation, confirming the relative rigidity of the
tricyclic system. However, these experiments revealed that the formerly
proposed stereochemistry of branimycin at 17-C should be revised.