7US 7us (3aM,9S,10bP,14S,15R,16S,17R,18R,19R,20S,21S,25R)-6,18,20-trihydroxy-14-methoxy-7,9,15,17,19,21,25-heptamethyl-1'-[2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl]-5,10,26-trioxo-3,5,9,10-tetrahydrospiro[9,4-(epoxypentadecanoimino)furo[2',3':7,8]naphtho[1,2-d]imidazole-2,4'-piperidin]-16-yl acetate 7US