InChI=1S/C21H28O11/c1-7-4-11(23)14-9(3)20(29)30-13(14)5-8(2)12(6-10(7)22)31-21-17(26)15(24)16(25)18(32-21)19(27)28/h5,10-18,21-26H,1,3-4,6H2,2H3,(H,27,28)/b8-5+