InChI=1S/C20H24O11/c21-12(22)10-8-6-4-2-1-3-5-7-9-11-16(29-11)19(28)31-20-15(25)13(23)14(24)17(30-20)18(26)27/h1-7,9,11,13-17,20,23-25H,8,10H2,(H,21,22)(H,26,27)/b2-1+,5-3-,6-4+,9-7+