InChI=1S/C20H18O9S/c1-19(9-27-30(23,24)25)5-4-11-6-17-14(8-15(11)29-19)20(22)10-26-16-7-12(21)2-3-13(16)18(20)28-17/h2-8,18,21-22H,9-10H2,1H3,(H,23,24,25)