InChI=1S/C32H28O4/c33-28(20-17-25-12-6-2-7-13-25)22-27(19-16-24-10-4-1-5-11-24)31-30(34)23-29(36-32(31)35)21-18-26-14-8-3-9-15-26/h1-16,18-19,21,23,27,34H,17,20,22H2/b19-16+,21-18+/t27-/m1/s1