InChI=1S/C21H18O10/c1-7-17(26)19(28)20(29)21(30-7)16-12(25)6-14-15(18(16)27)11(24)5-13(31-14)8-2-3-9(22)10(23)4-8/h2-7,19-23,25,27-29H,1H3/t7-,19+,20-,21+/m0/s1