Sujet(s)
Antibactériens/pharmacologie , Mitochondries du myocarde/enzymologie , Mitochondries/enzymologie , NADPH dehydrogenase (quinone)/antagonistes et inhibiteurs , NADPH dehydrogenase (quinone)/composition chimique , Animaux , Antifongiques/pharmacologie , Sites de fixation , Bovins , Escherichia coli/enzymologie , Glucose 1-dehydrogenase , Glucose dehydrogenases/antagonistes et inhibiteurs , Cinétique , Neurospora crassa/enzymologie , Relation structure-activitéRÉSUMÉ
The myxobacterium, Myxococcus virescens strain Mx v48 produced a family of at least 12 closely related antibiotics, the myxovirescins. At a concentration of 1 to 5 micrograms/ml, the main component, myxovirescin A, was bactericidal for many Gram-negative bacteria, in particular enterobacteria, and at 20 to 50 micrograms/ml it also inhibited some pseudomonads and Gram-positive bacteria. The antibiotics seem to interfere with cell wall synthesis. The molecular formula of myxovirescin A was C35H61NO8. It is a new antibiotic.
Sujet(s)
Antibactériens/pharmacologie , Bactéries/effets des médicaments et des substances chimiques , Myxococcales/analyse , Antibactériens/isolement et purification , Phénomènes chimiques , Chimie , Relation dose-effet des médicaments , Escherichia coli/effets des médicaments et des substances chimiques , Lactones/pharmacologieRÉSUMÉ
Myxothiazol is shown to be 4-(6-carbamoyl-3,5-dimethoxy-4-methylhexa-1E,5E-dienyl)-2'-(1,6-dimethylhepta-2 E,4E-dienyl)-2,4'-bithiazole by spectroscopic (mainly 1H NMR, 15C NMR and mass spectroscopic) and chemical methods.
Sujet(s)
Radio-isotopes du carbone , Hydrogène , Spectroscopie par résonance magnétique , Spectrométrie de masse , Méthacrylates , Conformation moléculaire , ThiazolesRÉSUMÉ
Myxothiazol (AB-Mx f16-1), a new antifungal antibiotic, is produced by the myxobacterium Myxococcus fulvus strain Mx f16. It is active against many filamentous fungi, and completely inhibits growth of Mucor hiemalis at a concentration of 2 micrograms/ml. The molecular formula of myxothiazol was determined to e C25H33N3O3S2.
Sujet(s)
Antifongiques/biosynthèse , Myxococcales/métabolisme , Animaux , Antifongiques/isolement et purification , Antifongiques/pharmacologie , Phénomènes chimiques , Chimie , Chimie physique , Embryon de poulet , Résistance microbienne aux médicaments , Fermentation , Champignons/effets des médicaments et des substances chimiques , Méthacrylates , Souris , Thiazoles/biosynthèse , Thiazoles/isolement et purification , Thiazoles/pharmacologieRÉSUMÉ
A new bacteriochlorophyll has been isolated by thin layer chromatography from all strains of the brown-colored Chlorobiaceae Chlorobium phaeobacteroides and Chlorobium phaeovibriodes. The new bacteriochlorophylle--like the bacteriochlorophylls c and d--represents the major amounts of bacteriochlorophyll a. Bacteriochlorophyll e can be differentiated from the bacteriochlorophylls c and d by its absorption maxima in aceton and its different Rf-value in the thin layer chromatogram. The structure of the new bacteriochlorophyll e has been elucidated on the basis of mass spectra, 1H-and 13C-NMR-spectra, the UV/VIS-spectrum as well as IR-, ORD-, and CD-spectra. The new bacteriochlorophyll has the same relationship to bacteriochlorophyll c as chlorophyll b from green plants to chlorophyll a; therefore, bacteriochlorophyll e represents the first formyl-substituted chlorophyll from bacteria. Similar to the bacteriochlorophylls c and d, the new bacteriochlorophyll e consists of a mixture of at least three homologues which differ from each other by different substituents on the pyrrol rings II and III.