InChI=1S/C21H20O7/c1-11-20(24)17(23)9-19(27-11)28-14-5-2-12(3-6-14)16-10-26-18-8-13(22)4-7-15(18)21(16)25/h2-8,10-11,17,19-20,22-24H,9H2,1H3/t11-,17-,19-,20+/m0/s1