InChI=1S/C22H20O4/c1-13-20(25)11-10-18-21(15-4-8-17(24)9-5-15)19(12-26-22(13)18)14-2-6-16(23)7-3-14/h2-11,19,21,23-25H,12H2,1H3/t19-,21-/m0/s1