InChI=1S/C20H20O11S/c1-28-15-7-4-13(10-17(15)31-32(25,26)27)11-18(20(23)24)30-19(22)8-5-12-3-6-14(21)16(9-12)29-2/h3-10,18,21H,11H2,1-2H3,(H,23,24)(H,25,26,27)/b8-5+/t18-/m0/s1