InChI=1/C28H22O6/c29-20-7-3-16(4-8-20)1-2-17-11-24(33)27-25(12-17)34-28(18-5-9-21(30)10-6-18)26(27)19-13-22(31)15-23(32)14-19/h1-15,26,28-33H/b2-1+/t26-,28+/s2