Possible relationships between taurine derivatives and products of the metabolism of ketimines

Within the class of six- and seven-membered sulfur-containing cyclic ketimines and their derivatives, some had been synthesized and chemically characterized long before a biochemical role was evidenced. In order to allow the identification of unknown compounds obtained by oxidation of ketimines or of their reduced counterparts, the synthesis of some derivatives of cysteic acid and taurine has been carried out. In this paper the synthesis of the derivative with cysteic acid (carboxylated-tauropine) will be described in detail and some properties will be reported. The same procedure performed with taurine gives a new taurine derivative which has not been described until now.