InChI=1S/C21H20O8S/c1-21(2)11-10-14-16(28-21)9-8-15(18(14)26-3)19-20(27-19)17(22)12-4-6-13(7-5-12)29-30(23,24)25/h4-11,19-20H,1-3H3,(H,23,24,25)