Threonine aldolases-screening, properties and applications in the synthesis of non-proteinogenic beta-hydroxy-alpha-amino acids.

Threonine aldolases (TAs) constitute a powerful tool for catalyzing carbon-carbon bond formations in synthetic organic chemistry, thus enabling an enantio- and diastereoselective synthesis of beta-hydroxy-alpha-amino acids. Starting from the achiral precursors glycine and an aldehyde, two new stereogenic centres are formed in this catalytic step. The resulting chiral beta-hydroxy-alpha-amino acid products are important precursors for pharmaceuticals such as thiamphenicol, a L: -threo-phenylserine derivative or L: -threo-3,4-dihydroxyphenylserine.