InChI=1S/C17H17NO9/c19-11(20)5-4-7-6-8-9(18-7)2-1-3-10(8)26-17-14(23)12(21)13(22)15(27-17)16(24)25/h1-6,12-15,17-18,21-23H,(H,19,20)(H,24,25)/b5-4+