Chemists Find New Vein Of Fluorinases

Naturally occurring organofluorine compounds are rare, with only five examples reliably known. The enzymes responsible for carbon-fluorine bond formation during the biosynthesis of those compounds are rarer still: Until now, only one has been identified. David O’Hagan of the University of St. Andrews, in Scotland, led the team that discovered the first fluorinase in 2002. O’Hagan and colleagues have now found three new versions of the enzyme (ChemBio­Chem 2014, DOI: 10.1002/cbic.201300732). After monitoring global databases of bacterial genomes for years, the researchers saw three fluorinase genes pop up from three genomes in the past two years. They implanted and then expressed the genes in Escherichia coli to confirm they code for fluorinases. The original fluorinase has been explored for efficiently introducing ¹⁸F into single-dose amounts of positron emission tomography imaging agents, O’Hagan notes. But limited success has been achieved in cloning the original fluorinase gene into other bacteria to produce organofluorine compounds. With the newly discovered versions, there’s more genetic information to see how different organisms handle fluorine metabolism, he says. Engineering fluorinase genes from the larger pool into other bacteria could lead to a viable fermentation technology for producing fluorinated drug candidates and fine chemicals, O’Hagan suggests.