InChI=1S/C18H16O10S/c19-14-9-11(5-7-17(20)21)4-6-15(14)27-16(18(22)23)10-12-2-1-3-13(8-12)28-29(24,25)26/h1-9,16,19H,10H2,(H,20,21)(H,22,23)(H,24,25,26)/b7-5+