Thesis - Open Access
Master of Science (MS)
The Jack bean plant is still the main source of canavanine. Kitagawa extracted canavanine from Jack bean with 50% alcohol and treated it with flavianic acid but the %N was lower than the theoretical value for this flavianate. In 1937 Kitagawa and Tsukamoto recommended the destruction of the impurity by digesting the first crude canavanine precipitate with 10% HC 1. They reported that this gave a high purity canavanine flavianate, but they did not give a detailed method nor the yield. In 1935 Gulland and Morris, who also had the same difficulty, suggested the purification of the base liberated from the flavianic acid salt by conversion into the rufianate. In 1939 Damodaran treated the crude canavanine with a solution of basic lead acetate, and then with flavianic acid. He got a. high purity flavianate successfully, but had trouble removing the excess lead. In 1962 a method was devised using ion-exchange resin to prevent the formation of desaminocanavanine with cold 99% alcohol from the concentrated canavanine extract, then treated it with flavianic acid, and decomposed the flavianate with hot saturated Ba(OH)2. The filtrate was passed through IR-48 (OH-form) ion-exchange resin to remove the impurity. The effluent was concentrated under reduced pressure and canavanine crystallized upon the addition of absolute alcohol. The merits of this method are that it gives the free canavanine in high purity, easily and in a good yield, directly from its flavianate. In the experiment of the author, the filtrate from decomposition with Ba(OH)2 was passed through AG-50W-8X resin and canavanine.2HC1 was eluted with 4N HCl. The effluent containing canavanine.2HC1 was passed through IR-4B (OH-form) resin to get free canavanine.
Library of Congress Subject Headings
Amino acids -- Synthesis
Number of Pages
South Dakota State University
Chen, Shu-Chiung W., "Biosynthesis of Canavanine" (1972). Electronic Theses and Dissertations. 4639.