InChI=1S/C20H28O8/c1-5-10(2)17(23)27-14-7-19(4)15(22)8-20(25,28-19)12(9-21)6-13-16(14)11(3)18(24)26-13/h5,12-16,21-22,25H,3,6-9H2,1-2,4H3/b10-5-