Streptogramins pristinamycin

ILA, viiginiamvcin Ml) streptogramin B pristinamycin virginiamycin Si S. virginiae, others P... 

Figure 8 Inactivation of type B streptogramin antibiotics by Vgb lyase. The type B streptogramins such as pristinamycin la (shown) are cyclic depsipeptides. Vgb lyase catalyzes the cleavage of the C-O depsipeptide bond.

Pristinamycin (rlNN) is a synergistic combination of streptogramin A (pristinamycin llA) and streptogramin B (pristinamycin IB). It is active against the main bacteria that cause respiratory tract infections and could be useful in the treatment of acute or recurrent sinusitis, community-acquired pneumonia, or periodontal infection with Actinobacillus actinomycetemcomitans (1-5). 

Pristinamycin and virginiamycin are two streptogramins that have been long been known. Pristinamycin is a mixture of synergistic components, pristinamycins I and II, the former being a macrolide and the latter a depsipeptide. 

Two important new streptogramins are quinu-pristin (Fig. 10.15A) and dalfopristin (Fig. 10.15B), which are derivatives of pristinamycin I and IIA, respectively. Individually, the two components are bacteristatic but in combination they act synergistically to produce a bactericidal effect by inhibiting early (dalfopristin) and late (quinupristin) phases of bacterial protein synthesis. These two antibiotics are used intravenously in combination (ratio 30 70) for the treatment of serious or life-threatening infections associated with vancomycin-resistant Enterococcus faecium bacteraemia, although the effect against this organism is bacteristatic. 

Trade names Pristinamycine Pyostacine (Sanofi-Aventis) Indications Staphylococcal streptococcal infections Category Antibiotic, streptogramin Half-life 4.03 2.77 hours... 

Fig. 3. Structure of streptogramin A, and when the bond denoted is saturated, of ostreogrycin G. Synonyms for streptogramin A are mikamycin A PA114A, pristinamycin IIA, vemamycin A, ostreogrycin A, virginiamycin Ml, and staphylomycin M. Synonyms for ostreogrycin G are virginiamycin M2...

The atoms of pristinamycin are numbered (Fig. 2) according to the method used by Anteunis and co-workers [29] for virginiamycin S (the name virginia-mycin S is reserved for the group B streptogramins according to Chemical Abstracts), where the first number identifies the residue (1 for threonine,... T for the 3-hydroxy picolinic residue), and the Greek suffix indicates the position in the chain (roman letters are used for heteroatomic positions). 

Despite the continued efforts of several research teams the total synthesis of pristinamycin 11 and related group A streptogramins remains a challenge. This paragraph cannot discuss in detail owing to space limitations all the accomplished efforts towards the total synthesis of these related antibiotics. The... 

Pristinamycin is a member of the streptogramin class of antibiotics effective against vancomycin-resistant S. aureus and vancomycin-resistant enterococcus. It is biosynthesized by the bacterium Streptomyces pristinaespiralis and consists of two components, pristinamycin lA (a macro-lide) and the depsipeptide pristinamycin HA (also known as streptogramin A) in the ratio of 30 70. Streptogramins, also called synergistins, are made up of two groups, streptogramins A and B. 

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