A paper chromatographic method for identification and estimation of pyrrolidone carboxylic acid.

Pyrrolidonecarboxylic acid (PCA) , which is readily formed by cyclization
of glutamine and other y-glutamyl derivatives, and from glutamic
acid under more drastic conditions (1,2), has recently received recognition
in enzymic reactions involving glutamic acid (3-6). For identification
of this compound on paper chromatograms, the procedure of Rydon and
Smith (7) for acylamino acids is generally employed (3). Apart from
being nonspecific, this method is also unsuitable for quantitative estimation
of PCA. An interesting chemical property of PCA-its capacity to
undergo quantitative conversion into y-glutamyl hydroxamate under
suitable conditions @)-has now been utilized for visual identification
of this compound on paper chromatograms as well as for its quantitative
estimation.