InChI=1/C20H26O7/c1-26-18-8-12(3-5-16(18)23)7-14(10-21)15(11-22)20(25)13-4-6-17(24)19(9-13)27-2/h3-6,8-9,14-15,20-25H,7,10-11H2,1-2H3/t14-,15-,20?/s2