Biochromatograms showing the first ever acylation of 6-APA

Photograph print of paper biochromatograms, titled ‘Penicin’, illustrating an experiment on 14 June 1957 at Beecham Research Laboratories at Brockham Park, described as the first ever acylation of 6-APA (6-aminopenicillanic acid), originally known as penicin

Biochromatograms are an example of chromatographs which show the separation of peptides and proteins. Acylation is a chemical reaction where an acyl group is added to a molecule, in this case penicillin.

In this experiment natural penicillins from P. chrysogenum culture ‘brew’ were removed with butyl acetate at acid pH and phenylacetylated or benzoylated or acetylated, resulting in the formation of the derivatives of 6-APA as shown in number 3 strip.

This research In 1957 by the team at Beecham Research Laboratories led to the development of several semi-synthetic penicillins. By tweaking 6 aminopenicillanic acid's chemical structure, scientists created medicines to treat a wider range of bacterial infections, with fewer side effects.

Frank Ralph Batchelor (1931-2021), Frank Doyle (1921-2006), John Nayler and George Rolinson (1928-2016) published their results in the journal Nature. Their careers focused on antibiotics, remaining at Beechams for most of their working lives.