InChI=1S/C18H16O9S/c1-9-14(24-2)7-12(19)16-17(20)11(8-26-18(9)16)10-4-5-13(15(6-10)25-3)27-28(21,22)23/h4-8,19H,1-3H3,(H,21,22,23)