InChI=1S/C20H28O8/c1-2-3-4-5-13(11-21)10-12-6-8-14(9-7-12)27-20-17(24)15(22)16(23)18(28-20)19(25)26/h6-10,15-18,20-24H,2-5,11H2,1H3,(H,25,26)/b13-10-