Definition: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.
Other names Heterocyclic N-Oxides; Oxides, Cyclic N; N-Oxides, Heterocyclic; N-Oxides, Cyclic; N Oxides, Cyclic; Heterocyclic N Oxides; Cyclic N Oxides
2,2,5,5-tetramethyl-1-pyrrolidinyloxy-3-carboxylic acid [ 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxide,3-carboxy-proxyl,TMPOCA ] structure given in first source