InChI=1S/C20H16O4/c1-11-8-12-6-7-15(21)19-18(12)17(9-11)24-20(19)14-4-3-5-16(22-2)13(14)10-23-20/h3-9,21H,10H2,1-2H3/t20-/m1/s1