InChI=1S/C21H20O14/c22-7(2-1-6-3-9(24)10(25)4-8(6)23)13-11(26)5-12(27)18(14(13)28)34-21-17(31)15(29)16(30)19(35-21)20(32)33/h1-5,15-17,19,21,23-31H,(H,32,33)/b2-1+