InChI=1S/C18H17NO7/c1-25-12-6-10(5-11(20)7-12)3-4-17(22)19-14-9-16(26-2)15(21)8-13(14)18(23)24/h3-9,20-21H,1-2H3,(H,19,22)(H,23,24)