Dissociation constants and structures of glutamic acid and its esters

IT has been shown [Neuberger, 1936] that the dissociation constants of simple zwitterions which contain only one carboxyl and one amino-group are quantitatively related to their structures; similarly the change of their apparent dissociation constants with the ionic strength of the solution of the different amino-acids can be satisfactorily explained on such a basis. This paper represents an extension of the previous work to a more complex zwitterion, namely glutamic acid. It was deemed desirable to determine also the dissociation constants of the different esters of glutamic acid and in this connexion the preparation of ac-ethyl hydrogen glutamate is described.