InChI=1S/C21H22O7/c1-12(15(22)11-21(2,3)20(24)25)6-8-27-19-13-4-5-18(23)28-17(13)10-16-14(19)7-9-26-16/h4-7,9-10,15,22H,8,11H2,1-3H3,(H,24,25)/b12-6+