InChI=1S/C20H18O6/c1-10(2)14(22)7-13-15(23)8-18-19(20(13)25)16(24)9-17(26-18)11-3-5-12(21)6-4-11/h3-6,8-9,14,21-23,25H,1,7H2,2H3