InChI=1S/C20H18O9/c21-8-16-17(25)18(26)20(29-16)28-15-7-12-13(24)5-11(23)6-14(12)27-19(15)9-1-3-10(22)4-2-9/h1-7,16-18,20-21,25-26H,8H2,(H2-,22,23,24)/p+1/t16-,17-,18+,20+/m1/s1