The development of commercial processes for the production of 6-aminopenicillanic acid (6-APA)

In the preceding paper Sir Ernst Chain described how the discovery of 6-APA and its subsequent conversion into a succession of therapeutically important semisynthetic penicillins has created a new international antibiotics industry. As the key raw material for this industry 6-APA has been transformed within the last decade, from a scientific curiosity into a fairly commonplace raw material which can now be produced in tonnage quantities; progress has been achieved by developing both microbial and chemical processes to this important compound (figure 1), and I would like to discuss the scientific background from which modern technologies have been evolved to provide this material.