Antibacterial agents which inhibit cell wall synthesis

5 Antibacterial agents which inhibit cell wall synthesis 

There are two major classes of drug which act in this fashion—penicillins and cephalosporins. We shall consider penicillins first. 

In 1877, Pasteur and Joubert discovered that certain moulds could produce toxic substances which killed bacteria. Unfortunately, these substances were also toxic to humans and of no clinical value. However, they did demonstrate that moulds could be a potential source of antibacterial agents. 

Fleming spent several years investigating the novel antibacterial substance and showed it to have significant antibacterial properties and to be remarkably non-toxic to humans. Unfortunately, the substance was also unstable and Fleming was unable to isolate and purify the compound. He therefore came to the conclusion that penicillin was too unstable to be used clinically. 

Although the use of penicillin was now widespread, the structure of the compound was still not settled and was proving to be a source of furious debate due to the unusual structures being proposed. The issue was finally settled in 1945 when Dorothy Hodgkins established the structure by X-ray analysis (Fig. 10.18). 

---