InChI=1S/C23H17NO7/c1-14(23(27)28)24-18(12-17-6-3-9-30-17)22(26)20(21(24)19-7-4-10-31-19)15(13-25)11-16-5-2-8-29-16/h2-14H,1H3,(H,27,28)/b15-11-,18-12+