InChI=1S/C16H18O12S/c17-9-3-1-8(5-10(9)18)2-4-13(20)27-12-7-16(23,15(21)22)6-11(19)14(12)28-29(24,25)26/h1-5,11-12,14,17-19,23H,6-7H2,(H,21,22)(H,24,25,26)/b4-2-