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Pristinamycin IIB
Pristinamycin IIB is an antibiotic of the streptogramin A class. It was isolated from '' Streptomyces pristinaespiralis'' and its chemical structure was first determined in 1966. See also * Pristinamycin IIA Pristinamycin IIA is a macrolide antibiotic. It is a member of the streptogramin A group of antibiotics and one component of pristinamycin (the other being pristinamycin IA). Pristinamycin IIA was first isolated from the Streptomyces virginiae, ... References Macrolide antibiotics Oxazoles {{antibiotic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antiseptics) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptogramin A
Streptogramin A is a group of antibiotics within the larger family of antibiotics known as streptogramins. They are synthesized by the bacteria '' Streptomyces virginiae''. The streptogramin family of antibiotics consists of two distinct groups: group A antibiotics contain a 23-membered unsaturated ring with lactone and peptide bonds while group B antibiotics are depsipeptides (lactone-cyclized peptides). While structurally different, these two groups of antibiotics act synergistically, providing greater antibiotic activity than the combined activity of the separate components. These antibiotics have until recently been commercially manufactured as feed additives in agriculture, although today there is increased interest in their ability to combat antibiotic-resistant bacteria, particularly vancomycin-resistant bacteria. Biosynthesis Streptogramin A is a polyketide in nature, but contains some amino acid components as well. Its gene cluster codes for a hybrid PKS-NRPS protein t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomyces Pristinaespiralis
''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, and have genomes with high GC content. Found predominantly in soil and decaying vegetation, most streptomycetes produce spores, and are noted for their distinct "earthy" odor that results from production of a volatile metabolite, geosmin. Streptomycetes are characterised by a complex secondary metabolism. They produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin, streptomycin, cypemycin, grisemycin, bottromycins and chloramphenicol). The antibiotic streptomycin takes its name directly from ''Streptomyces''. Streptomycetes are infrequent pathogens, though infections in humans, such as mycetoma, can be caused by '' S. somaliensis'' and '' S. sudanensis'', and in plants can be caused by '' S. cavis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristinamycin IIA
Pristinamycin IIA is a macrolide antibiotic. It is a member of the streptogramin A group of antibiotics and one component of pristinamycin (the other being pristinamycin IA). Pristinamycin IIA was first isolated from the Streptomyces virginiae, but has been isolated from other microorganisms and thus has been given a variety of other names such as Virginiamycin M1, Mikamycin A, and Streptogramin A. Pristinamycin IIA structure was determined by chemical and instrumental techniques, including X-ray crystallography. Pristinamycin IIA is of interest from a biosynthetic viewpoint because it contains the unusual dehydroproline and oxazole ring systems. The only experimental evidence bearing on the formation of the oxazole ring is found in work on the biosynthesis of the alkaloid annuloline. __TOC__ Biosynthesis Pristinamycin IIA biosynthesis is presumed to proceed through the acetate pathway and was determined through the feeding of 3H and 13C precursors to Streptomyces virginiae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrolide Antibiotics
The Macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Macrolides belong to the polyketide class of natural products. Some macrolides have antibiotic or antifungal activity and are used as pharmaceutical drugs. Rapamycin is also a macrolide and was originally developed as an antifungal, but is now used as an immunosuppressant drug and is being investigated as a potential longevity therapeutic. Macrolides are bacteriostatic in that they suppress or inhibit bacterial growth rather than killing bacteria completely. Definition In general, any macrocyclic lactone having greater than 8-membered rings are candidates for this class. The macrocycle may contain amino nitrogen, amide nitrogen (but should be differentiated from cyclopeptides), an oxazole ring, or a thiazole ring. Benzene rings are excluded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
