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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 Antibiotic
The Macrolides are a class of natural products that consist of a large macrocycle, 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 Life extension, 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 Amine, amino nitrogen, amide nitrogen (but should be differentiated from Cyclopeptide, cyclopeptides), an oxazole ring, ... [...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] |
Pristinamycin
Pristinamycin ( INN), also spelled pristinamycine, is an antibiotic used primarily in the treatment of staphylococcal infections, and to a lesser extent streptococcal infections. It is a streptogramin group antibiotic, similar to virginiamycin, derived from the bacterium '' Streptomyces pristinaespiralis''. It is marketed in Europe by Sanofi-Aventis under the trade name Pyostacine. Pristinamycin is a mixture of two components that have a synergistic antibacterial action. Pristinamycin IA is a macrolide, and results in pristinamycin's having a similar spectrum of action to erythromycin. Pristinamycin IIA (streptogramin A) is a depsipeptide. PI and PII are coproduced by ''S. pristinaespiralis'' in a ratio of 30:70. Each compound binds to the bacterial 50 S ribosomal subunit and inhibits the elongation process of the protein synthesis, thereby exhibiting only a moderate bacteriostatic activity. However, the combination of both substances acts synergistically and leads to a potent b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristinamycin IA
Pristinamycin IA (Mikamycin B) is an antibiotic cyclic peptide. It is a member of the streptogramin B group of antibiotics and one component of pristinamycin (the other being 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, ...). Notes Antibiotics Peptides Isonicotinamides {{antibiotic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomyces Virginiae
''Streptomyces virginiae'' is a bacterium species from the genus of ''Streptomyces'' which has been isolated from soil.Deutsche Sammlung von Mikroorganismen und Zellkulturenbr>/ref> ''Streptomyces virginiae'' produces actithiazic acid, virginiamycins and cycloserine. ''Streptomyces virginiae'' also produces monensin A, monensin B, monensin C, monensin D, actithiazic acid. Further reading * * * * * * * * * * See also * List of Streptomyces species A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union ... References External linksType strain of ''Streptomyces virginiae'' at Bac''Dive'' - the Bacterial Diversity Metadatabase virginiae Bacteria described in 1952 {{Streptomyces-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxazole
Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base; its conjugate acid has a p''K''a of 0.8, compared to 7 for imidazole. Preparation Classical oxazole synthetic methods in organic chemistry are * the Robinson–Gabriel synthesis by dehydration of 2-acylaminoketones * the Fischer oxazole synthesis from cyanohydrins and aldehydes * the Bredereck reaction with α-haloketones and formamide * the Van Leusen reaction with aldehydes and TosMIC Other methods: * Oxazolines can also be obtained from cycloisomerization of certain propargyl amides. In one study oxazoles were prepared via a one-pot synthesis consisting of the condensation of propargyl amine and benzoyl chloride to the amide, followed by a Sonogashira coupling of the terminal alkyne end with another equivalent of benzoylchlor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methionine
Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical role in the metabolism and health of many species, including humans. It is encoded by the codon AUG. Methionine is also an important part of angiogenesis, the growth of new blood vessels. Supplementation may benefit those suffering from copper poisoning. Overconsumption of methionine, the methyl group donor in DNA methylation, is related to cancer growth in a number of studies. Methionine was first isolated in 1921 by John Howard Mueller. Biochemical details Methionine (abbreviated as Met or M; encoded by the codon AUG) is an α-amino acid that is used in the biosynthesis of proteins. It contains a carboxyl group (which is in the deprotonated −COO− form under biological pH conditions), an amino group (which is in the protonated fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proline
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L-glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG). Proline is the only proteinogenic secondary amino acid which is a secondary amine, as the nitrogen atom is attached both to the α-carbon and to a chain of three carbons that together form a five-membered ring. History and etymology Proline was first isolated in 1900 by Richard Willstätter who obtained the amino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serine
Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − form under biological conditions), and a side chain consisting of a hydroxymethyl group, classifying it as a polar amino acid. It can be synthesized in the human body under normal physiological circumstances, making it a nonessential amino acid. It is encoded by the codons UCU, UCC, UCA, UCG, AGU and AGC. Occurrence This compound is one of the naturally occurring proteinogenic amino acids. Only the L-stereoisomer appears naturally in proteins. It is not essential to the human diet, since it is synthesized in the body from other metabolites, including glycine. Serine was first obtained from silk protein, a particularly rich source, in 1865 by Emil Cramer. Its name is derived from the Latin for silk, ''sericum''. Serine's structure was estab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (GGU, GGC, GGA, GGG). Glycine is integral to the formation of alpha-helices in secondary protein structure due to its compact form. For the same reason, it is the most abundant amino acid in collagen triple-helices. Glycine is also an inhibitory neurotransmitter – interference with its release within the spinal cord (such as during a ''Clostridium tetani'' infection) can cause spastic paralysis due to uninhibited muscle contraction. It is the only achiral proteinogenic amino acid. It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom. History and etymology Glycine was discovered in 1820 by the French chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valine
Valine (symbol Val or V) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α- carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain isopropyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, beans and legumes. It is encoded by all codons starting with GU (GUU, GUC, GUA, and GUG). History and etymology Valine was first isolated from casein in 1901 by Hermann Emil Fischer. The name valine comes from valeric acid, which in turn is named after the plant valerian due to the presence of the acid in the roots of the plant. Nomenclature According to IUPAC, carbon atoms forming valine are numbered sequentially s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutyric Acid
Isobutyric acid, also known as 2-methylpropanoic acid or isobutanoic acid, is a carboxylic acid with structural formula ( CH3)2CH COOH. It is an isomer of ''n''- butyric acid. It is classified as a short-chain fatty acid. Deprotonation or esterification gives derivatives called isobutyrates. Isobutyric acid is a colorless liquid with a somewhat unpleasant odor. It is soluble in water and organic solvents. It is found naturally in carobs (''Ceratonia siliqua''), in vanilla, and in the root of ''Arnica dulcis'', and as an ethyl ester in croton oil. Production Isobutyric acid is manufactured by the oxidation of isobutyraldehyde, which is a byproduct of the hydroformylation of propylene. It can also be prepared by the high pressure hydrocarboxylation ( Koch reaction) from propylene: :CH3CH=CH2 + CO + H2O → (CH3)2CHCO2H Isobutyric acid can also be manufactured commercially using engineered bacteria with a sugar feedstock. Laboratory methods Many routes are known includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
