Abstract
Physicochemical Comparisons were made on Naramycin-B and isocycloheximide, which are stereoisomers of cycloheximide, and it was confirmed that the two antibiotics are similar but not quite equal to each other, and that, mainly from the interpretations of their rotatory dispersion curves, the absolute configurations of Naramycin-B and isocycloheximide respectively belong to(2S : 4S : 6R : αS)-and (2R : 4S : 6R : αS)-series.