InChI=1S/C20H16O7S/c1-26-17-10-13-4-2-3-11-5-7-14(19(18(11)13)20(17)22)12-6-8-15(21)16(9-12)27-28(23,24)25/h2-9,17,21H,10H2,1H3,(H,23,24,25)