InChI=1S/C21H26O6/c1-11-12(2)21(14-9-17(25-4)19(23)18(10-14)26-5)27-20(11)13-6-7-15(22)16(8-13)24-3/h6-12,20-23H,1-5H3/t11-,12+,20-,21+/m1/s1