Researchers have discovered a pathway for introducing fluorine atoms into naturally occurring molecules.

Fluorine is present in up to 30% of pharmaceuticals and can expand the usefulness of natural products by, for example, increasing the time they take to break down in the body. But until now, chemists have been using a single method — the fluoroacetate pathway — to insert fluorine into organic molecules.

Michelle Chang of the University of California, Berkeley, and her colleagues have found a different way to insert atoms of the element into a useful group of molecules called polyketides. Their method enlists a soil bacterium (Streptomyces cattleya) for the first steps. The bacterium binds fluorine to carbon, making building blocks such as fluoroacetate monomers that can then be inserted into polyketides in the place of acetate.

The team demonstrated the method in the laboratory and in living cells, in which they were able to control where the fluorine atoms ended up in the polyketide molecules.

Science 341, 1089–1094 (2013)