Virginiamycin antibiotic

Antibiotics approved for use as growth enhancers in Hvestock and poultry include bacitracins, bambermycins, Hncomycin [154-21 -2] penicillin [69-53 ] streptomycin [57-92-1], tetracycHnes, tiamulin [55297-95-5] tylosin [1401-69-0] and virginiamycin [11006-76-1] (61). 

Some other antibiotics commonly used in animal production such as the bacitracins, bambermycins and virginiamycins as well as the streptomycins are poorly absorbed from the intestinal tract and residues usually do not occur from feeding. Chloramphenicol is used illegally in the United States in many species it is used legally in Europe, Canada and other parts of the world. 

Peptide antibiotics are compounds containing amino acids that are covalently linked to other chemical entities and consist of more than one component. In contrast to naturally occurring proteins that are built up from L-amino acids only, peptide antibiotics usually contain o-amino acids. Avoparcin, bacitracin, efroto-mycin, enramycin, thiopeptin, and virginiamycin constitute the main members within this group of drugs (Fig. 6.2). They are usually added to animal feeds at low concentrations, and produce residues in tissues at very low or undetectable levels. Unfortunately, the metabolic pathways of most peptide antibiotics have not been still elucidated. Within the European Union, these antibiotics are regulated under a separate legislation (Directive 70/524/EEC). 

A number of additives have, since the original feed additives list in 1970, been withdrawn from the list of authorized additives for different reasons including their contribution to the generation of resistance to bacteria (avoparcin, tylo-sin, virginiamycin), and the decision to restrict certain antibiotics to therapeutic use (penicillin, streptomycin, tetracyclines). Until recently there has been an incoherence between feed additive and veterinary medicine legislation in the European Union since use of some agents such as dimetridazole and ronidazole was... 

The majority of these are antibiotics and they cover a diverse group including the glycopeptide, avoparcin (95), tetracycline, macrolides, such as tylosin (23) and virginiamycin (96), as well as peptides, glycopeptides and terpenes. Antibacterials such as the quinoxaline-1,4-dioxide, carbadox (39), and nitrofurans, e.g. furazolidone (35) and nitrovin (97), are also represented. 

B. Group A Peptide Antibiotics of the Mikamycin/Streptogramin/Virginiamycin Family... 

Pulsawat N, Kitani S, Nihira T. Characterization of biosynthetic gene cluster for the production of virginiamycin M, a streptogramin type A antibiotic, in Streptomyces virginiae. Gene 2007 393 31-42. 

Table 7 lists the peptide antibiotics of commercial interest and their producers. Annual U.S. sales of peptide antibiotics, as wholesale price to pharmacies, can be approximated from the following estimates bleomycin, 25 million for 2 kg bacitracin, polymyxin, and gramicidin D, 100 million total for 4 t, 10 kg, and 400 g respectively and cyclosporine, 130 million (3 t). Minor peptides having less than 1 million sales each, such as capreomycin and dactinomycin, are sold at a loss. U.S. agricultural sales figures for bacitracin, 20 million (>200 t), and virginiamycin, 12—15 million (ca 70 t), are indicative of the 1991 market. 

S,47 ) -Hydroxypipecolic acid [(-)-a3 -4-hydroxy-2-piperidine carboxylic acid, 3] was isolated from the leaves of Calliandra piuieri and Strophantus scandeus and it was identified as a constituent of cyclopeptide antibiotics, such as virginiamycin S2. It was also employed as a precursor in the preparation of selective N-methyl-D-aspartate receptor antagonists. Furthermore, (-)-3 has served as a building block in a recent synthesis of palinavir, a potent peptidomimetic-based HIV protease inhibitor. ... 

S, Vernamycin B. Group of peptide lactones produced by Streptomyces loidensis Donovick el ah, U.S. pat, 2,990,325 (1961 tn Olin Mathieson). Antimicrobial antibiotic structurally similar to virginiamycin S, q.v. Bodan-... 

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