InChI=1S/C20H26O7/c1-10-8-18-9-19(10,27)7-4-11(18)20(16(25)26)6-3-5-17(2,15(23)24)13(20)12(18)14(21)22/h11-13,27H,1,3-9H2,2H3,(H,21,22)(H,23,24)(H,25,26)