Biosynthesis of Halogenated Tyrosines

Interestingly, a study of the bromide-dependent chloroperoxidase bromination of tyrosine reveals that the active brominating agent is free bromine and not a bromine-enzyme complex [122]. The situation is very different for bromoperoxidase- and vanadium peroxidase-catalyzed brominations [106-108]. 

Crews has also formulated a biosynthetic pathway for the disulfide bromotyrosine psammaplins from the sponge Pseudoceratina purpurea [64,126]. The structurally unique ma edamines (80, 81) may be derived from a dehydro derivative of aplysa-mine-2 or purpuramine H via cyclization and dehydroxylation [69]. The numerous bromotyrosine alkaloids that contain an aminopropanol unit, such as nakirodin A (71), may be derived from a homoserine unit through decarboxylation [60]. The 

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