Biotransformations
Abstract
This report reviews significant developments in applications of biological catalysis in synthetic organic chemistry for the year 2005. In addition to the continued use of commercially available hydrolases and oxidoreductase enzymes, advances have been made in the in vitro improvement of enzyme activity, through increasing combinations of protein structure-based rational and irrational mutagenesis methods. These mutation studies have also led to growing interest in the area of catalytic promiscuity, whereby wild-type enzymes or their mutants are observed to catalyse reactions distinct from those ordinarily attributed to them. Important advances have been reported in the practical electrochemical regeneration of cofactors for oxidoreductases, and in the engineering of cytochromes P450 for the oxidation of ethane to ethanol. Finally, the use of sugar-modifying enzymes continues apace, with many novel methods for the selective introduction of the sialic acid moiety, and imaginative routes for the synthesis and regeneration of nucleotide sugar donors for glycosyltransfer reactions.