Altamycin A

4-[11-[(2,6-Dideoxy-β-D-ribo-hexopyranosyl)oxy]-8,10,12-trimethyl-1-oxo-2,4,6,8-tridecatetrenyl]-2,5-dihydro-3-hydroxy-1-methyl-5-oxo-1H-pyrrole-2-propanoic acid

4-[11-[(2,6-Dideoxy-β-D-ribo-hexopyranosyl)oxy]-1-oxo-8,10,12-trimethyl-2,4,6,8-tridecatetrenyl]-2,5-dihydro-3-hydroxy-1-methyl-5-oxo-1H-pyrrole-2-propionic acid