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