InChI=1S/C16H20O8/c1-22-8-2-3-9-4-6-10(7-5-9)23-16-13(19)11(17)12(18)14(24-16)15(20)21/h2-7,11-14,16-19H,8H2,1H3,(H,20,21)/b3-2+