InChI=1S/C20H16O7S/c1-25-14-9-11-3-2-4-13-15(11)17(18(14)21)16(20-19(13)26-20)10-5-7-12(8-6-10)27-28(22,23)24/h2-8,14,19-20H,9H2,1H3,(H,22,23,24)