3a,7-Epoxy-3aH-furo(3,2-b)oxocin-3-carboxylic acid, 5-(6-(2,5-dihydro-4-hydroxy-2-oxo-1H-pyrrol-3-yl)-1,3-dimethyl-6-oxo-2,4-hexadienyl)octahydro-2,6,9a-trimethyl-8-oxo-, methyl ester 69774-87-4 69831-39-6 Antibiotic BU-2313 B BU-2313 B