InChI=1S/C20H16O7S/c1-26-20-18(22)17-14(11-5-8-13(21)9-6-11)10-7-12-3-2-4-15(16(12)17)19(20)27-28(23,24)25/h2-10,19-21H,1H3,(H,23,24,25)