InChI=1S/C22H20O4/c1-25-18-9-4-15(5-10-18)22-19-11-8-17(24)12-21(19)26-13-20(22)14-2-6-16(23)7-3-14/h2-12,20,22-24H,13H2,1H3/t20-,22-/m0/s1