|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:issue |
4
|
|
pubmed:dateCreated |
2005-6-28
|
|
pubmed:abstractText |
During the screening program for new antibacterial agents produced by actinomycetes, GE23077 was isolated from fermentation broths of an Actinomadura sp. strain as a complex of factors A1, A2, B1, B2. NMR, MS and GC/MS analysis carried out on the isolated components led to the conclusion that GE23077 is a novel cyclic heptapeptide consisting of common and unusual amino acids. The chemical structures of the complex components were elucidated. Components A and B differ in the structure of the acyl group connected to a 2,3-diaminopropanoic acid moiety. A alpha-amino-malonic acid residue in the peptidic sequence is the origin of an isomerization process between A1 and A2 as well as B1 and B2. The chirality of the alpha-amino-malonic acid residue can be inverted easily via keto-enol tautomerism. Factors A2 and B2 should be considered as epimers of A1 and B1 respectively. By degradation studies the absolute configuration of some amino acids were determined. Chiral GC-MS and Micellar Electrokinetic Capillary Chromatography (MEKC) were used to define the absolute stereochemistries of five out of ten chiral centers.
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
|
|
pubmed:status |
MEDLINE
|
|
pubmed:month |
Apr
|
|
pubmed:issn |
0021-8820
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:volume |
58
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
260-7
|
|
pubmed:dateRevised |
2006-11-15
|
|
pubmed:meshHeading |
pubmed-meshheading:15981412-Amino Acids,
pubmed-meshheading:15981412-Anti-Bacterial Agents,
pubmed-meshheading:15981412-Bacteria,
pubmed-meshheading:15981412-Chromatography, High Pressure Liquid,
pubmed-meshheading:15981412-Chromatography, Micellar Electrokinetic Capillary,
pubmed-meshheading:15981412-DNA-Directed RNA Polymerases,
pubmed-meshheading:15981412-Gas Chromatography-Mass Spectrometry,
pubmed-meshheading:15981412-Magnetic Resonance Spectroscopy,
pubmed-meshheading:15981412-Molecular Conformation,
pubmed-meshheading:15981412-Peptides, Cyclic,
pubmed-meshheading:15981412-Protein Hydrolysates,
pubmed-meshheading:15981412-Spectrometry, Mass, Electrospray Ionization,
pubmed-meshheading:15981412-Spectrometry, Mass, Fast Atom Bombardment,
pubmed-meshheading:15981412-Stereoisomerism
|
|
pubmed:year |
2005
|
|
pubmed:articleTitle |
Antibiotics GE23077, novel inhibitors of bacterial RNA polymerase. II. Structure elucidation.
|
|
pubmed:affiliation |
Vicuron Pharmaceuticals via R. Lepetit, 34, 21040, Gerenzano (Varese) Italy. amarazzi@vicuron.it
|
|
pubmed:publicationType |
Journal Article
|
