InChI=1S/C20H20O5/c1-11(9-21)3-4-13-5-6-15-18(19(13)23)20(24)17-14(10-22)7-12(2)8-16(17)25-15/h3,5-8,21-23H,4,9-10H2,1-2H3/b11-3-