US EPA

8261716 

Journal Article 

Discussion on the Diketopiperazin Theory for Chemical Structure of Eisenin. Part 1. Examination of Diketopiperazin Reaction on Eisenin 

Ohira, T; Imai, K; Kido, H 

1955 

1 

Nippon Nogeikagaku Kaishi
ISSN: 0002-1407
EISSN: 1883-6844 

29 

3 

237-241 

English 

10.1271/nogeikagaku1924.29.237 

These experiments were tried to clarify the problem proposed by Dr. Y. TAZAWA about the chemical structure of eisenin, and it has been thought to be true that the chemical structure of eisenin is l-pyrrolidonoyl-α-l-glutaminyl-l-alanine as it was reported by OHIRA, one of the authers, previously, according to the following experimental results. 1. The diketopiperazine reactions were examined upon eisenin, its related substances and typical diketopiperazines, with o-dinitrobenzene, m-dinitrobenzen and picric acid as the reagents for the reactions, and the reaction color of eisenin was found to be positive only in the case of using m-dinitrobenzen, but the reaction color was too weak to be recognized as the diketopierazine reaction. 2. The weak reaction of diketopiperazine was given by synthetic l-pyrrolidonoyl-α-l-glutamyl-diamide, i.e. the analogous substance of eisenin, but the reaction was not brought about at all by l-pyrrolidonoyl-α-l-glutamyl-diethy lester from which the diamide mentioned above was made. 3. The peptide which was yielded by ammonolysis of 5-methyl-1-[l-pyrrolidonoyl-α-l-glutaminyl]-2-thiohydantion derived from eisenin was exactly identical with synthetic l-pyrrolidonoyl-α-l-glutamyl-diamide considering the comparison of their X-ray diffraction diagrams. © 1955, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.