InChI=1S/C20H28O7/c1-9-6-15-12(10(2)18(24)26-15)7-13-11(9)4-5-20(13,3)27-19-17(23)16(22)14(21)8-25-19/h6,11-17,19,21-23H,2,4-5,7-8H2,1,3H3