InChI=1S/C18H19NO4/c1-11-14-9-17(21-2)15(20)7-12(14)5-6-19(11)13-3-4-16-18(8-13)23-10-22-16/h3-4,7-9,11,20H,5-6,10H2,1-2H3/t11-/m1/s1