InChI=1S/C21H28O9/c1-2-3-10-15(11-8-6-4-5-7-9-14(23)12-13-22)29-21-18(26)16(24)17(25)19(30-21)20(27)28/h1,8,11,13-19,21,23-26H,4-7,9,12H2,(H,27,28)/b11-8+