InChI=1S/C18H18O8S/c1-9-16(20)10(2)18-15(17(9)24-3)13(19)8-14(25-18)11-4-6-12(7-5-11)26-27(21,22)23/h4-7,14,20H,8H2,1-3H3,(H,21,22,23)