InChI=1S/C21H20O14/c22-7(12-8(23)5-9(24)13(27)14(12)28)2-1-6-3-10(25)18(11(26)4-6)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+