InChI=1S/C20H18O7S/c1-20(2)12-11-16-18(26-20)10-6-14(19(16)22)5-9-17(21)13-3-7-15(8-4-13)27-28(23,24)25/h3-12,22H,1-2H3,(H,23,24,25)