InChI=1S/C20H20O9S/c1-10(9-27-30(24,25)26)4-5-14-12(3)19-17(8-15(14)22)28-16-7-13(21)6-11(2)18(16)20(23)29-19/h4,6-8,21-22H,5,9H2,1-3H3,(H,24,25,26)/b10-4+