InChI=1S/C23H20O6/c24-20-15-13-19(18-21(20)25)14-16-23(28)29-17-11-9-7-5-3-1-2-4-6-8-10-12-22(26)27/h4,6,13-16,18,24-25H,2,8,10,12,17H2,(H,26,27)/b6-4+,16-14+