InChI=1S/C20H18O10/c21-13-4-1-10(7-15(13)23)8-16(20(28)29)30-18(26)6-3-11-2-5-14(22)19(27)12(11)9-17(24)25/h1-7,16,21-23,27H,8-9H2,(H,24,25)(H,28,29)/b6-3+