84777-85-5 AM-2604 A Antibiotic AM-2604 A Concanamycin A, 23-O-de(4-O-(aminocarbonyl)-2,6-dideoxy-beta-D-arabino-hexopyranosyl)-23-O-(4-((2-hydroxy-5-oxo-1-cyclopenten-1-yl)amino)-1,4-dioxo-2-butenyl)- Virustomycin A