InChI=1S/C21H20O11S/c1-9(2)5-13(23)16-12(8-30-33(26,27)28)18-20(17(24)19(16)29-4)32-21(25)15-10(3)6-11(22)7-14(15)31-18/h5-7,22,24H,8H2,1-4H3,(H,26,27,28)