InChI=1S/C20H25NO4/c1-14(2)12-21-19(22)8-6-4-3-5-7-17-20(25-17)15-9-10-16-18(11-15)24-13-23-16/h3-4,6,8-11,14,17,20H,5,7,12-13H2,1-2H3,(H,21,22)/b4-3+,8-6+