InChI=1S/C20H25NO4/c1-14(2)12-21-20(22)19-17(25-19)8-6-4-3-5-7-15-9-10-16-18(11-15)24-13-23-16/h5-11,14,17,19H,3-4,12-13H2,1-2H3,(H,21,22)/b7-5+,8-6+