InChI=1S/C21H21NO5/c1-15(23)26-19-10-8-18(14-20(19)27-16(2)24)9-11-21(25)22-13-12-17-6-4-3-5-7-17/h3-11,14H,12-13H2,1-2H3,(H,22,25)/b11-9+