InChI=1S/C21H22O6/c1-21(24)9-11-7-8-13(22)18(16(11)14(23)10-21)19-12-5-4-6-15(25-2)17(12)20(26-3)27-19/h4-8,19-20,22,24H,9-10H2,1-3H3/t19-,20+,21+/m1/s1