Rifampicin chemical structure

Figure 3.6 Comparison of the chemical structures of rifamycin (Rifampicin ) and rifamycin CGP 4832 the latter is transported by FhuA. Note the entirely different chemical structures (Figure 3.2) and conformations (Figure 3.5) of the ferrichrome and albomycin FhuA transport substrates.

Fig. 2. Chemical structures of rifampicin and rifaximin as well as of their parent compound, rifamycin SV. The empirical formula of rifaximin is C43H51N3O11 and its molecular weight 785.9 daltons.

Fig. 6. Chemical structures of the rifamycin nucleus and of rifampicin (/ = l-amino-4-methylpiperazine)...

Rifamycins B and O can be transformed into rifamycin S, and rifamycin SV is obtained by treating rifamycin S with ascorbic acid [5]. Formylation of the C3 position of rifamycin SV, followed by the combination of this alkaloid with l-amino-4-methylpiperazine, gave the semisynthetic ansamy-cin rifampicin. Rifampicin was prepared in 1966, and it is one of the most effective antituberculosis agents at present. The chemical structures of the rifamycins were finally clarified in 1973-1974 [6,7]. 

If a drug fails to meet present day standards because of low in vitro potency, metabolic, or chemical instability, poor oral absorption or high degree of serum and tissue binding, experience teaches that the prospects for improvement via structural modification are good—if systematic structural modification with retention of biological activity is feasible. The clinically established semisynthetic cephalosporins, rifamycin SV and rifampicin represent precisely this kind of improvement, while laboratory data indicate that it has also been achieved in the coumermycin series as well (96, 97). 

The discovery of rifampicin in 1967 is considered one of the greatest achievements in the history of chemotherapy against tuberculosis. Rifampin was developed in the Lepetit Research Laboratories (Italy) as part of an extensive program of chemical modification of the rifamycins, the natural metabolites of Nocardia mediterranei. All of the studies leading to highly active derivatives were performed on a molecule (rifamycin B) that was itself practically inactive. Systematic structural modifications of most of the functional groups of the rifamycin molecule were... 

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