InChI=1S/C20H18O8/c1-27-15-9-11(3-5-17(21)22)7-13(19(15)25)14-8-12(4-6-18(23)24)10-16(28-2)20(14)26/h3-10,25-26H,1-2H3,(H,21,22)(H,23,24)/b5-3+,6-4+