InChI=1S/C20H20O7/c1-22-17-7-12(3-4-15(17)21)27-20-14-9-23-19(13(14)8-24-20)11-2-5-16-18(6-11)26-10-25-16/h2-7,13-14,19-21H,8-10H2,1H3/t13-,14-,19+,20+/m0/s1