Bacteriostats nitrofuran derivative

In contrast, there are substances like some nitrofurane derivatives for which the presence of particular molecular structures is the decisive condition. Thus, a nitrofurane derivative prepared by Casini and his co-workers (87) has shown bacteriostatic properties similar to classical low molecular preparations of nitrofurane, e.g. l-[5-(nitrofurfuryliden)amino]hydantoine. The polymeric substance shows an activity considerably longer than that of the reference substance if parenterally applied, whereas oral application gives no effect. This is easy to understand because, as already mentioned, polymers cannot be resorbed in the digestive tract. Here, the active polymeric substance [22] has been prepared by condensation of 5-nitrofuraldehyde with poly(acryloylhydrazide). 

For example, the original scarlet red colour changes to yellow on heating for 30 minutes at 120° and the chemical structure of the compound changes considerably (see p. 338). The bacteriostatic activity of the yellow solution against dysentery bacillus is about 250 times greater than that of panazone. This observation has prompted the synthesis of other di-(nitrofuran) derivatives, some of which are listed in Table 6.8. 

The mechanism of antibacterial action of the furan derivatives is unknown. However, the reduced forms of nitrofurans are highly reactive and are thought to inhibit many bacterial enzyme systems, including the oxidative decarboxylation of pyruvate to acetylcoenzyme A. Nitrofurans (see list in Table 1.7) are bacteriostatic but, at high concentrations, can be bactericidal to sensitive organisms. Both chromosomal and plasmid-mediated mechanisms of resistance to nitrofurantoin occur, and these most commonly involve the inhibition of nitrofuran reductase. 

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