InChI=1S/C17H20O9/c1-17(2)6-5-7-9(26-17)4-3-8(18)13(7)24-16-12(21)10(19)11(20)14(25-16)15(22)23/h3-6,10-12,14,16,18-21H,1-2H3,(H,22,23)