InChI=1S/C13H12O12S/c14-7-3-1-6(5-8(7)15)2-4-9(16)24-10(12(17)18)11(13(19)20)25-26(21,22)23/h1-5,10-11,14-15H,(H,17,18)(H,19,20)(H,21,22,23)/b4-2-