InChI=1S/C18H18O8S/c1-25-18(21)15(13-10-6-3-7-11-13)14(12-8-4-2-5-9-12)16(17(19)20)26-27(22,23)24/h2-11,14-16H,1H3,(H,19,20)(H,22,23,24)