InChI=1S/C13H16O7/c1-6-2-4-7(5-3-6)19-13-10(16)8(14)9(15)11(20-13)12(17)18/h2-5,8-11,13-16H,1H3,(H,17,18)/t8-,9-,10+,11-,13+/m0/s1