InChI=1S/C20H24O7S/c1-11-12(2)20(27-28(22,23)24)16-10-18(26-4)17(21)9-15(16)19(11)13-6-5-7-14(8-13)25-3/h5-12,19-21H,1-4H3,(H,22,23,24)