InChI=1S/C16H20O7/c1-9(20-10(2)17)12(21-11(3)18)7-8-14-16(23-14)13-5-4-6-15(19)22-13/h4,6-9,12-14,16H,5H2,1-3H3/b8-7+/t9-,12+,13+,14-,16+/m0/s1