InChI=1S/C21H28O9/c1-10-4-3-5-12(6-7-13-11(2)19(26)28-14(13)8-10)20(27)30-21-18(25)17(24)16(23)15(9-22)29-21/h5,8,13-18,21-25H,2-4,6-7,9H2,1H3/b10-8-,12-5+