InChI=1S/C20H20O6/c1-9-3-11-13(21)5-17-20(25-8-24-17)19(11)18(10(9)2)12-4-15-16(23-7-22-15)6-14(12)26-20/h4-6,9-11,18-19H,3,7-8H2,1-2H3/t9-,10+,11+,18+,19+,20+/m1/s1