Aeruginosins, which were produced by the cyanobacteria, were composed by three amino acids derivatives (Hpla ; p-hydroxy-phenyllactic acid, Choi ; 2-carboxy-6-hydroxyoctahydroindole and Arg derivatives) and one usual amino acid. These peptides showed strong protease inhibitory acyivities against trypsin, plasmin and thrombin.
In this study, I can not find the key compound of biosynthesis of aeruginosins, which was contained Arg at N-terminal of-peptide. But, the aeruginosins 102-A and -B,and the aeruginosin 103-A were isolated from the Microcystis viridis (NIES-102,103). These peptides possesed argininal at N-terminal. I also could isolate the aeruginosins 205-A and B from Oscillatoria agardhii (NIES-205), which were composed by agmatine, Choi, 3-hydroxyleucine, xylopyranose and Hpla. From these results, the biosynthetic pathway of aeruginosins was thought to be reducing pathway from Arg to argininal, argininol or agmatin. Unfortunately, the biosynthetic pathway of Choi could not be clearly defined from the incorpolation experience of labeled ^<13>C-Tyr.
Furthermore, I can clarified the aeruginosin 98-B's complete absolute stereostructure along with the mechanism of trypisn inhibition from the Xray analisis of the complex of trpsin and aeruginosin 98-B.