InChI=1S/C20H18O7/c21-14-5-18-17(26-9-27-18)4-11(14)20-13-7-22-19(12(13)6-23-20)10-1-2-15-16(3-10)25-8-24-15/h1-5,12-13,19-21H,6-9H2/t12-,13-,19+,20-/m0/s1