InChI=1S/C15H20N2O8S/c1-15(7-18)5-11(20)13-12(25-15)3-2-9(14(13)17)10(19)4-8(16)6-24-26(21,22)23/h2-3,8,18H,4-7,16-17H2,1H3,(H,21,22,23)