InChI=1S/C20H18O11/c21-6-15-17(27)18(28)20(31-15)30-14-5-9-10(23)3-8(22)4-13(9)29-19(14)7-1-11(24)16(26)12(25)2-7/h1-5,15,17-18,20-21,27-28H,6H2,(H4-,22,23,24,25,26)/p+1/t15-,17+,18-,20+/m0/s1