InChI=1S/C15H16N2O7/c16-8-5-4-6-2-1-3-7(9(6)17-8)23-15-12(20)10(18)11(19)13(24-15)14(21)22/h1-5,10-13,15,18-20H,(H2,16,17)(H,21,22)