51773-74-1 (1S,3Z,5Z,7S,9Z,11E,13S,15R)-13-hydroxy-2-{[(2R)-2-hydroxypropanoyl]amino}-1,4,10,19-tetramethyl-17,18-dioxo-16-oxabicyclo[13.2.2]nonadeca-3,5,9,11-tetraen-7-yl acetate 51733-45-0 (1S,2R,3Z,5E,7S,9Z,11Z,13S,15R,19R)-7-hydroxy-1,4,10,19-tetramethyl-17,18-dioxo-2-[(2-oxopropanoyl)amino]-16-oxabicyclo[13.2.2]nonadeca-3,5,9,11-tetraen-13-yl pentanoate