Understanding antibiotic resistance
Understanding antibiotic resistance

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Understanding antibiotic resistance

1.2 Synthetic and semi-synthetic antibiotics

The very first antibiotics were discovered by screening large numbers of existing compounds from collections of chemical compounds known as chemical libraries. These were arsenic derivatives in the case of Salvarsan in 1909, and azo-dyes for sulfonamides in the 1930s.

More targeted screening of chemical libraries later became the norm, such as looking for inhibitors of bacteria-specific metabolic pathways. This is how synthetic carbapenems were discovered (Silver, 2011).

Semi-synthetic antibiotics are derivatives of natural antibiotics with slightly different but advantageous characteristics. For example, they can act against bacteria which are resistant to the original compound, have a greater spectrum of activity or cause fewer side effects.

Semi-synthetic derivatives of penicillins and cephalosporins are known as generations. You will find out more about cephalosporin generations in this week’s case study.

In the next section, you will find out how antibiotics are produced on an industrial scale.


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