InChI=1S/C20H20O11/c21-10-6-9(3-1-8-2-4-11(22)12(23)5-8)17(13(24)7-10)30-20-16(27)14(25)15(26)18(31-20)19(28)29/h1-7,14-16,18,20-27H,(H,28,29)/b3-1+