Purification of canavanine from the legume Vicia disperma

Abstract

Vicia disperma is an annual legume that accumulates high amounts of the non-protein amino acid canavanine in the seeds. The purification of this amino acid from the seeds of V. disperma has been investigated in order to assess the possibility of using this plant as a source of canavanine. Seeds had 3% (w/w) canavanine content, representing 84.3% (w/w) total free amino acids. Canavanine was extracted from seed flour extracts at pH 4 and purified by nanofiltration and ion-exchange chromatography, followed by either precipitation or crystallization, yielding canavanine 90% and 97% pure, respectively. This represents a simple and inexpensive procedure for production of canavanine, taking advantage of the high content of canavanine in V. disperma. This could have a very beneficial impact on the use of V. disperma and other Vicia rich in canavanine, some of which have good agronomic properties and were farmed in the past.