InChI=1S/C18H22O9/c1-3-10(19)6-4-9-5-7-11(25-2)8-12(9)26-18-15(22)13(20)14(21)16(27-18)17(23)24/h4-8,13-16,18,20-22H,3H2,1-2H3,(H,23,24)/b6-4+