InChI=1S/C16H20N2O7/c1-17-9(4-5-10(17)19)8-3-2-6-18(7-8)15-13(22)11(20)12(21)14(25-15)16(23)24/h2-3,6-7,9,11-15,20-22H,4-5H2,1H3