InChI=1S/C21H22O10S/c1-27-17-10-13(5-6-16(17)31-32(24,25)26)20-15(11-22)14-8-12(4-7-19(23)29-3)9-18(28-2)21(14)30-20/h4-10,15,20,22H,11H2,1-3H3,(H,24,25,26)/b7-4+