InChI=1S/C21H32O9/c1-11(2)5-6-15(23)13(4)10-14(9-12(3)7-8-22)29-21-18(26)16(24)17(25)19(30-21)20(27)28/h5,7-8,10,14-19,21,23-26H,6,9H2,1-4H3,(H,27,28)/b12-7+,13-10-