Free Amino Acids and Related Substances in Marine Organisms

摘要

A survey of the free amino acids of over 400 tissues of marine organisms revealed a number of new compounds. An acidic amino acid was isolated from sea anemones and proved to be 2-aminoethylphosphonic acid (2-AEP). A new lipid, ceramide 2-amino-ethylphosphonic acid was isolated from sea anemones and characterized. Investigation of precursors of 2-AEP led to the isolation of a new alpha-amino acid, phosphonoalanine. The analogy of these with common nitrogenous bases led to the discovery of three more C-P compounds, N-methyl-2 AEP, N-dimethyl-2 AEP. Lipids containing the mono and trimethyl compounds were isolated. An investigation of the degradation of 2-AEP demonstrated the existence of a transaminase in Anthopleura and Tetrahymena using alpha-ketoglutarate as an acceptor. A study of the transport of aminoalkylphosphonic acids by bacteria revealed that they are taken up by the alpha-amino acid transport system. Biosynthesis of 2-AEP was shown to occur only during cell division and studies with 14C labeled precursors indicated that the most likely precursor is either phosphoenolpyruvic acid or oxaloacetate. Examination of zooplankton revealed that 3% of the total phosphorus was in C-P compounds. Cultures of coccolithophorids and dinoflagellates in labeled media demonstrated that these phytoplankton synthesize phosphonic acids. (Author)