The 50th anniversary of the discovery of 6-aminopenicillanic acid (6-APA)

This year (2007) marks the 50th anniversary of the discovery of 6-aminopenicillanic acid (6-APA), the precursor of all semi-synthetic penicillins and cephalosporins—the β-lactam antibiotics. This review, by a scientist who played a major part in the discovery and a physician who participated in the early clinical trials of these antibiotics, tells the story of the discovery and of the early development of the β-lactam antibiotics that revolutionised the treatment of infections.

Reviews EditorI.M. GouldI have pleasure in introducing this review, which is published in celebration of the half century since the discovery of the penicillin ‘nucleus’—6-aminopenicillanic acid (6-APA). This discovery enabled the development of the semi-synthetic penicillins that have proved so important in clinical practice and that are only under serious threat today with the advent of virulent new clones of methicillin-resistant Staphylococcus aureus (MRSA).The authors are a distinguished scientist who was one of the team of chemists and microbiologists at Beecham Research Laboratories involved in the discovery of 6-APA in 1957, and a clinician who participated in many of the early clinical studies of the semi-synthetic penicillins and cephalosporins that defined the golden age of antimicrobial chemotherapy.