Chemists from the Philipps-Universität Marburg, Germany, have reported a highly selective one-step synthesis of natural products. This approach uses enzymes to convert polycyclic precursors into aszonalenins. 

The enzymes (prenyltransferases) catalyse the creation of a five-membered ring between the indoline and the seven-membered ring system. Using this feature the team, led by Shuming Li, developed successfully a chemoenzymatic synthesis of four aszonalenin stereoisomers. The crucial step used prenyltransferases to control the stereochemistry in the final product. In fact the team found that stereoselectivity of the one-step reactions was close to 100% and the conversion rates reached 85-100%. 

'With the increasing number of sequenced genomes and identified genes as well as improved molecular and biochemical methods, more and more recombinant proteins including enzymes could be produced easily in good yields' says Li, adding that 'more and more enzymes will be used in combination with a classical chemical approach for synthesis of complicated molecules including pharmaceuticals.' 

Russell Johnson