{[(1S,3E,5S,6R,7S,8R,9S,10S,12R,13E,15Z)-7-acetoxy-9,12,20,22-tetrahydroxy-5-methoxy-1,6,8,10,12,16,23-heptamethyl-11,17,26-trioxo-18-aza-2,25-dioxatetracyclo[17.6.5.021,28.024,27]triaconta-3,13,15,19(20),21(22),23,27(28),29-octaen-29-yl]oxy}acetic acid