InChI=1S/C20H22O8/c21-10-16-17(24)18(25)19(26)20(28-16)27-15-5-3-11(4-6-15)1-2-12-7-13(22)9-14(23)8-12/h1-9,16-26H,10H2/b2-1+/t16-,17?,18+,19?,20-/m1/s1