InChI=1S/C21H22O8/c1-9-5-11(22)7-13(23)16(9)20(26)28-14-6-10(2)17(19(24)25)18-12(14)8-15(29-18)21(3,4)27/h5-7,15,22-23,27H,8H2,1-4H3,(H,24,25)