Science is currently trying to find effective solutions to overcome the mutations of
bacteria that lead to anti-bacterial resistance.In fact, penicillin is the major antibiotic
administrated internationally, but because of bacterial mutations, it is no longer as
effective as it initially used to be. The discovery of antibiotics that possess different
molecular structures is now more important than ever in the pharmaceutical industry.
Therefore, this project will discuss and study the very first antibiotic that was discovered;
sulfonamides.
The aim of this project is to synthesize different sulfonamide-type molecules to then test
and compare their activity on two different bacterial cultures.
More precisely, sulfathiazole and sulfa-5-methylthiazole will be synthesized and then
tested on E. Coli (Gram-negative bacteria) and streptococcus mutans (Gram positive
bacteria) to compare their antibacterial activity.
Since a small amount of each antibiotic has been able to be synthesized, the first aim of
this experience was successfully achieved. Moreover, because the Infrared absorption
spectroscopies and fusion points have been obtained, it was possible to characterize the
synthesized antibiotics. For sulfathiazole, a melting point of 185.6°C has been obtained,
while wulfa-5-methylthiazole had a melting point of 206.5°C.
Concerning their Infrared absorption spectroscopies, the synthetic antibiotics did indeed
have the main functions intended.
In terms of the biological results, the antibiotic sulfa-5-methylthiazole was effective on
both bacterial cultures while sulfathiazole was only effective on e-coli. However, the
antibiogram of sulfathiazole had a larger inhibition diameter than sulfa-5-methylthiazole,
which invalidates the initial hypothesis. This means that a more lipophilic molecule may
well penetrate the bacterial wall, but may not bind well to its enzyme.
It is possible to conclude that this scientific experience proves that sulfonamides are
broad-spectrum antibiotics.