InChI=1S/C21H22O6/c1-13(6-9-21(2,3)20(23)24)7-10-26-19-14-4-5-18(22)27-17(14)12-16-15(19)8-11-25-16/h4-5,7-8,11-12H,6,9-10H2,1-3H3,(H,23,24)/b13-7+