InChI=1S/C21H24O8/c1-27-16-9-13(8-14(23)10-16)3-2-12-4-6-15(7-5-12)28-21-20(26)19(25)18(24)17(11-22)29-21/h2-10,17-26H,11H2,1H3/b3-2-