InChI=1S/C16H12O11S/c17-10-3-1-8(5-11(10)18)6-14(16(21)22)26-12-4-2-9(15(19)20)7-13(12)27-28(23,24)25/h1-7,17-18H,(H,19,20)(H,21,22)(H,23,24,25)/b14-6-