InChI=1S/C17H13NO9/c19-10-3-1-8(5-11(10)20)6-14(16(23)24)27-13-4-2-9(7-12(13)21)15(22)18-17(25)26/h1-7,19-21H,(H,18,22)(H,23,24)(H,25,26)/b14-6-