Ezomycins, structures

The trans-fused perhydrofuropyran system is also encountered in the ezomycin group of nucleoside antibiotics (6,7). The structures of ezomycin Aj and Aj are shown in Figure 3 for comparison with the octosyl acids. 

Cj, C2, Dj, and Dj from fermentation broths of a Streptomyces species (see also Vol. 8, p. 130) possess the structures shown in Scheme 84. Ezomycins Bj, Cj, and Dj, as well as ezomycins Bj, Cj, and Dj, interconvert under mild acidic conditions. 

The structures of the ezomycins, which contain 5-substituted uracil residues, are noted on p. 155. 5-) -D-Ribofuranosyluracil ( -uridine) has been converted... 

Aspiculamycin is not a tripeptidyl amino-sugar derivative (see Vol. 8, p. 130), but is identical with gougerotin. Following last year s report on the structure of ezomycin Ai (see Vol. 8, p. 130), the structures of related complexes (Bi, Bg, Q, Ci, Dx, and Ds) have been elucidated, and a mechanism has been suggested for their interconversion. ... 

The structure of an antifungal antibiotic, ezomycin A (206), isolated from a Streptomyces species, has been established, using degradative and spectral evidence. ... 

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