Dibromo-tyrosine derivatives

This pyridoxal-phosphate-dependent enzyme [EC 2.6.1.24] catalyzes the reversible reaction of 3,5-diiodo-tyrosine with a-ketoglutarate (or, 2-oxoglutarate) to generate 3,5-diiodo-4-hydroxyphenylpyruvate and glutamate. Also acting as substrates are the 3,5-dichloro, 3,5-dibromo, and the 3-iodo derivatives of tyrosine, as well as thyroxine and triiodothyronine. 

All of the Amathia brominated amides are presumably biosynthesised from amino acids by similar pathways in the related bryozoans. The amathamides are amides derived formally by reaction of 2-(2,4-dlbromo-5-methoxyphenyl)ethanamlne, 68, with proline followed variously by introduction of a double bond, or methyl, methoxy or bromine substituents. The A. convoluta metabolites 70-74, and 75 from A. alternata are all also derived formally from 2-(2,4-dibromo-5-methoxy-phenyDethanamlne, 68—either by direct amide formation with tyrosine, or by having an additional aminopropyl group which is then... 

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