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