InChI=1/C18H17NO7/c20-13-4-1-10(8-15(13)22)3-6-17(24)19-12(18(25)26)7-11-2-5-14(21)16(23)9-11/h1-6,8-9,12,20-23H,7H2,(H,19,24)(H,25,26)/b6-3+/t12-/s2