InChI=1S/C21H21NO6/c1-22-7-6-12-8-17(25-2)18(26-3)9-14(12)20(24)19(23)13-4-5-16-21(15(13)10-22)28-11-27-16/h4-5,8-9H,6-7,10-11H2,1-3H3