[(9S,12E,14S,15R,16S,17R,18R,19R,20S,21S,22E,24Z)-6,18,20-Trihydroxy-14-methoxy-7,9,15,17,19,21,25-heptamethyl-1'-(2-methylpropyl)-5,10,26-trioxo-3,5,9,10-tetrahydro-2H-spiro[9,4-(epoxypentadeca[1,11,13]trienazandiyl)furo[2',3':7,8]naphtho[1,2-d]imidazol-2,4'-piperidin]-16-yl]acetat