InChI=1S/C21H20O10S/c1-21(2)17(31-32(25,26)27)7-12-16(30-21)8-14(23)18(20(12)28-3)13-9-29-15-6-10(22)4-5-11(15)19(13)24/h4-6,8-9,17,22-23H,7H2,1-3H3,(H,25,26,27)