InChI=1S/C28H22O8S/c29-21-10-5-17(6-11-21)4-7-20-14-23(31)16-25-26(20)27(28(35-25)18-8-12-22(30)13-9-18)19-2-1-3-24(15-19)36-37(32,33)34/h1-16,27-31H,(H,32,33,34)/b7-4+