InChI=1S/C20H16N2O8/c1-7(23)30-19-14-12(17(27)18(28)20(19,2)29)11-13(22(14)6-21)16(26)10-8(15(11)25)4-3-5-9(10)24/h3-5,17-19,24,27-29H,1-2H3/t17-,18+,19+,20+/m0/s1