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