26-((1E)-2-{Imino(nitroamino)methyl]amino}-2-azavinyl)(7S,11S,13S,17S,18S,12R,14R,15R,16R)-2,15,17,27,29-pentahydroxy-11-methoxy-3,7,12,14,16,18,22-heptamethyl-6,23-dioxo-8,30-dioxa-24-azatetracyclo[23.3.1.1<4,7