InChI=1S/C20H20N2O9S/c1-11(23)16(9-18(25)26)22-19(27)13-4-2-12(3-5-13)10-21-32(30,31)14-6-7-17(24)15(8-14)20(28)29/h2-8,16,21,24H,9-10H2,1H3,(H,22,27)(H,25,26)(H,28,29)/t16-/m0/s1