InChI=1S/C19H18O11S/c1-28-15-8-11(2-5-13(15)20)4-7-18(22)29-17(19(23)24)10-12-3-6-14(21)16(9-12)30-31(25,26)27/h2-9,17,20-21H,10H2,1H3,(H,23,24)(H,25,26,27)/b7-4+/t17-/m0/s1