InChI=1S/C20H22O7/c1-10(8-21)2-4-13-16(24)7-17(25)18-19(26)14(9-27-20(13)18)12-5-3-11(22)6-15(12)23/h3,5-7,10,14,21-25H,2,4,8-9H2,1H3