Halogen complexes biosynthesis

Nature utilizes the shikimate pathway for the biosynthesis of amino acids with aryl side chains. These nonprotein amino acids are often synthesized through intermediates found in the shikimate pathway. In many cases, L-a-amino acids are functionalized at different sites to yield nonprotein amino acids. These modifications include oxidation, hydroxylation, halogenation, methylation, and thiolation. In addition to these modifications, nature also utilizes modified biosynthetic pathways to produce compounds that are structurally more complex. When analyzing the structures of these nonprotein amino acids, one can generally identify the structural similarities to one of the L-a-amino acids with aromatic side chains. 

To illustrate mechanisms by which complex halogenated secondary metabolites are elaborated, the haloperoxidase-mediated biosynthesis of selected halometabolites elaborated by marine microorganisms will be described. The discussion given by Neidleman20 of chloramphenicol biosynthesis provides an example of bacterial halometabolite biosynthesis, while fungal halometabolite biosynthetic schemes are found in the monograph by Turner21. 

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