InChI=1S/C21H20O9/c22-9-16-18(25)19(26)20(27)21(30-16)29-15-7-11(23)6-14-17(15)12(24)8-13(28-14)10-4-2-1-3-5-10/h1-8,16,18-23,25-27H,9H2