InChI=1S/C16H17NO4/c18-9-2-1-8-7-11-16(20)4-3-10(19)14-15(16,5-6-17-11)12(8)13(9)21-14/h1-2,11,14,17-18,20H,3-7H2/t11-,14+,15+,16-/m1/s1