InChI=1S/C25H22O6/c1-12(2)9-18-21-23(28)20-19(11-17-14(22(20)27)7-8-25(3,4)31-17)30-24(21)15-6-5-13(26)10-16(15)29-18/h5-11,18,26-27H,1-4H3