InChI=1S/C16H18O8/c17-10-4-1-9(2-5-10)3-6-13(20)24-14-11(18)7-16(23,15(21)22)8-12(14)19/h1-6,11-12,14,17-19,23H,7-8H2,(H,21,22)/b6-3+