InChI=1S/C21H20O13S/c1-31-20-14(21-17(27)18(11(24)7-32-21)34-35(28,29)30)19-13(15(25)16(20)26)10(23)6-12(33-19)8-2-4-9(22)5-3-8/h2-6,11,17-18,21-22,24-27H,7H2,1H3,(H,28,29,30)