InChI=1S/C20H18O11/c21-8-3-10(22)9-5-15(31-20-18(28)17(27)13(25)6-29-20)19(30-14(9)4-8)7-1-11(23)16(26)12(24)2-7/h1-5,13,17-18,20,25,27-28H,6H2,(H4-,21,22,23,24,26)/p+1/t13-,17-,18+,20+/m0/s1