InChI=1S/C21H22O12/c1-29-11-6-10(31-15(23)7-11)4-3-9-5-14(13(30-2)8-12(9)22)32-21-18(26)16(24)17(25)19(33-21)20(27)28/h3-8,16-19,21-22,24-26H,1-2H3,(H,27,28)/b4-3+