InChI=1S/C17H18O9/c18-7-12-14(21)15(22)16(23)17(26-12)25-11-6-10-9(3-4-24-10)5-8(11)1-2-13(19)20/h1-6,12,14-18,21-23H,7H2,(H,19,20)/b2-1+