(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-tetrahydrospiro[9,4-(epoxypentadeca[1,11,13]trienimino)-2H-furo[2′,3′:7,8]naphtho[1,2-d]imidazole-2,4′-piperidine]-16-yl acetate