InChI=1/C28H22O7/c29-19-6-2-15(3-7-19)1-4-16-9-22(32)14-25-26(16)27(18-10-20(30)13-21(31)11-18)28(35-25)17-5-8-23(33)24(34)12-17/h1-14,27-34H/b4-1+