InChI=1S/C21H22O9S/c1-21(2)11-15(23)19-17(29-21)10-16(28-3)18(20(19)24)14(22)9-6-12-4-7-13(8-5-12)30-31(25,26)27/h4-10,15,23-24H,11H2,1-3H3,(H,25,26,27)