InChI=1S/C13H20O9/c1-2-3-4-5-6(11(17)18)21-13-9(16)7(14)8(15)10(22-13)12(19)20/h3-4,6-10,13-16H,2,5H2,1H3,(H,17,18)(H,19,20)/b4-3-