InChI=1S/C19H20O9/c1-9(26-19-15(22)13(20)14(21)16(28-19)17(23)24)6-7-11-8-10-4-2-3-5-12(10)18(25)27-11/h2-9,13-16,19-22H,1H3,(H,23,24)/b7-6+