(7R,11S,12R,13S,14S,15S,16S,18S,26Z)-2,15,17,29-Tetrahydroxy-11-methoxy-3,7,12,14,16,18,22-heptamethyl-26-{[(4-methyl-1-piperazinyl)amino]methylene}-6,23,27-trioxo-8,30-dioxa-24-azatetracyclo[23.3.1.1
4,7.05,28]triaconta-1(28),2,4,9,19,21,25(29)-heptaen-13-yl acetate