InChI=1S/C21H28O17S/c22-6-12-16(27)19(30)21(37-12,8-35-39(31,32)33)38-20-18(29)17(28)15(26)13(36-20)7-34-14(25)4-2-9-1-3-10(23)11(24)5-9/h1-5,12-13,15-20,22-24,26-30H,6-8H2,(H,31,32,33)/b4-2+