InChI=1S/C16H20O9/c1-2-16(23,8-6-4-3-5-7-8)15(22)25-14-11(19)9(17)10(18)12(24-14)13(20)21/h3-7,9-12,14,17-19,23H,2H2,1H3,(H,20,21)