Formation of Derivatives

Twonew nikkomycins were isolated from the fermentation broth of Streptomyces tendae Tii 901/PF 53+-3. These new metabolites, nikkomycins pseudo-Z (<^-Z, 1) and pseudo-J (<^-J, 2) differ from the corresponding nikkomycins Z and J by a C-glycosidic bond between C-5 of uracil and C-l' of 5-amino-5-deoxy-D-<z//0-furanuronic acid instead of an JV-glycosidic bond. The structure elucidation was achieved by two-dimensional NMR techniques and mass spectrometry.