InChI=1S/C15H14O11/c16-8-3-1-7(5-9(8)17)2-4-11(20)26-12(13(21)22)15(25,14(23)24)6-10(18)19/h1-5,12,16-17,25H,6H2,(H,18,19)(H,21,22)(H,23,24)/b4-2+