InChI=1S/C17H20O9/c18-11(7-6-10-4-2-1-3-5-10)24-8-9-25-17-14(21)12(19)13(20)15(26-17)16(22)23/h1-7,12-15,17,19-21H,8-9H2,(H,22,23)/b7-6+