dinactin and monactin

Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Gram-Positive Bacteria; Lakes; Liquid-Liquid Extraction; Macrolides; Microbial Sensitivity Tests; Russia; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptomyces; Tandem Mass Spectrometry

The optimization of the biosynthetic pathways is highly attractive for the large-scale preparation of macrotetrolides, because overall yields in the chemical synthesis of compounds like nonactin have been very low. A key success factor determining the outcome of such optimizations is the adequate process analysis for the envisioned product. The analytical methods for process control involved in the past spectrophotometric and chromatographic measurements. LC-MS offers a modern approach to obtain more detailed data than the spectrophotometric and chromatographic measurements used in the past. In this work, a fast and versatile analytical LC-MS method has been set up, which has proven of much value for the in-process analysis of macrotetrolides during fermentation and which has allowed rapid large-scale bioprocess development.

Topics: Chromatography, Liquid; Fermentation; Industrial Microbiology; Macrolides; Mass Spectrometry; Molecular Structure; Pyrans; Streptomyces griseus

A macrotetrolide preparation including nonactin (about 75 per cent), monactin (about 23 pr cent) and traces of dinactin and trinactin was analyzed with the method of UV spectroscopy. It was shown to form hydrophobic complexes in organic solvents with picrates of univalent cations of ammonium, potassium and sodium. The complex strength depended not only on the cation nature, but also on the solvent and pH of the picrate aqueous solutions. The comparison of methylene chloride used for tetrananactin with chloroform demonstrated that nonactin formed stable complexes in chloroform at neutral pH of the aqueous phase, a solution of picric acid and ammonium chloride.

Topics: Anti-Bacterial Agents; Cations, Monovalent; Drug Combinations; Hydrogen-Ion Concentration; Macrolides; Picrates; Potassium; Quaternary Ammonium Compounds; Sodium; Solubility; Spectrophotometry, Ultraviolet; Water

A mixture of antibiotic substances was isolated from the culture fluid of a recombinant strain of Streptomyces chrysomallus. The substances were identified as macrotetrolides (nonactin, monactin, dinactin and trinactin) by the mass spectrometry, ionoform properties and thin layer chromatography in the antibiotic samples and ethylacetate extracts of the fermentation broth filtrate. The parent strain of Streptomyces chrysomallus also synthesized a mixture of macrotetrolides. However, it contained no nonactin and the total level of the macrotetrolide biosynthesis was 5 to 7 time lower than that in the recombinant strain (determined by a chemical method).

Topics: Anti-Bacterial Agents; Chromatography, Thin Layer; Culture Media; Macrolides; Streptococcus

Macrotetrolides isolated from a new producer, Streptomyces globisporus, were identified as nonactin, monactin, dinactin and trinactin. Spectroscopic characterization of these compounds was extended by 13NMR spectra. Chemical ionization with ammonia as reactive gas was proposed for mass-spectroscopic characterization of their mixtures. Their biological activity was confirmed by using larvae of the Colorado potato beetle (Leptinotarsa decemlineata) as a new test model.

Topics: Animals; Anti-Bacterial Agents; Coleoptera; Insecticides; Macrolides; Molecular Structure; Pest Control, Biological; Streptomyces

Topics: Anti-Bacterial Agents; Chromatography, High Pressure Liquid; Macrolides; Magnetic Resonance Spectroscopy; Spectrophotometry, Ultraviolet

The effects of methylation on the rate constants of carrier-mediated ion transport have been studied on monooleindecane bilayers with K+, Rb+, NH4+, and Tl+ ions, using the series of homologue carriers, nonactin, monactin, dinactin, trinactin, and tetranactin, each member of the series differing from the previous one by only one methyl group. Measurements of the amplitude and time constant of the current relaxation after a voltage jump over a large domain of voltage and permeant ion concentration, together with a computer curve-fitting procedure, have allowed us, without the help of steady-state current-voltage data, to deduce and compare the values of the various rate constants for ion transport: formation (kRi) and dissociation (kDi) of the ion-carrier complex at the interface, translocation across the membrane interior of the carrier (ks) and the complex (kis). With the additional information from steady-state low-voltage conductance measurements, we have obtained the value of the aqueous phase-membrane and torus-membrane partition coefficient of the carrier (gammas and gammas). From nonactin to tetranactin with the NH4+ ion, kis, and gammas are found to increase by factors of 5 and 3, respectively, kDi and gammas to decrease respectively by factors 8 and 2, while kRi and ks are practically invariant. Nearly identical results are found for K+, Rb+, and Tl+ ions. kRi, ks and kis are quite invariant from one ion to the other except for Tl+ were kRi is about five times larger. On the other hand, kDi depends strongly on the ion, indicating that dissociation is the determining step of the ionic selectivity of a given carrier. The systematic variations in the values of the rate constants with increasing methylation are interpreted in terms of modification of energy barriers induced by the carrier increasing size. Within this framework, we have been able to establish and verify a fundamental relationship between the variations of kis and kDi with methylation.

Topics: Anti-Bacterial Agents; Electric Conductivity; Glycerides; Lipid Bilayers; Macrolides; Mathematics; Membranes; Models, Biological; Potassium; Pyrans; Rubidium; Structure-Activity Relationship; Tellurium

Topics: Anti-Bacterial Agents; In Vitro Techniques; L Cells; Macrolides; Mycobacterium bovis; Pharmacology; Research; Staphylococcus; Tissue Culture Techniques; Toxicology