Abstract
A substance giving postitive Sakaguchi reaction was examined from the extract of Cristaria plicata Leach by paper microelectrophoresis, microbiological assay, Sakaguchi reaction, and ion exchange resins. Several kinds of guanidyl derivatives were found which had not been found in the extract of shell-fish, such as arginine, agmatin, alkain, and octopine. One of such derivatives was not adsorbed by the ion exchanger, Amberlite IRC-50, and this was a peptide-like, almost neutral substance which precipitated by phosphotungstic acid. When boiled in acid, this formed a guanidyl derivative which showed no arginine-activity with Streptococcus faecalis. The portion which did not precipitate by phosphotungstic acid also showed the presence of a substance with positive Sakaguchi reaction. This substance is almost neutral. Other substances which were detected included the peptide of arginine and a substance with positive Sakaguchi reaction which moved towards the acid side. Ninhydrin-coloring substances were examined with two-dimensional paper chromatography and 13 kinds of amino acids, including glutamic acid and aspartic acid, were found besides a fair amount of glutamine and asparagine, and a large amount of the peptide of glutamic acid.
