X-ray molecular movie of penicillin reveals hidden lives of its intermediates

Chemists have tracked the fleeting intermediates in the natural synthesis of penicillin using ultrashort x-ray pulses. The research could usher in improvements in ring-forming reactions on useful intermediates for the pharmaceutical industry or aid enzyme engineering.

Penicillins and related ß-lactam antibiotics remain crucial medicines, accounting for more than half of the antibiotics given each year. Until now, the intermediates involved in the reaction have been too short-lived to observe directly and the complex ring-forming reaction has never been performed with a chemical catalyst.