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M G Brazhnikova

Publications and source records attributed to M G Brazhnikova.

At least 19 recordsLinked to original sources
PubMed1991

[Early identification of streptothricin group antibiotics].

Methodical approaches to detecting cultures producing streptothricins at the early stages of screening new antibiotics were developed. The approaches are based on chromatographic and electrophoretic mobility of streptothricins and the products of their hydrolysis in the extracts from agar cultures of actinomycetes. Application of the method for screening new antibiotics is illustrated with an example. Nine strains of actinomyces with broad antibacterial spectra isolated from soil samples were studied and 6 of them belonging to 4 species were shown to produce streptothricins in agar cultures. The new streptothricin-producing culture S. roseolilacinus was isolated.

Hydrolysis↗
PubMed1989

Eremomycin--new glycopeptide antibiotic: chemical properties and structure.

By a combination of chemical and spectroscopic (1H and 13C NMR) studies the structure of a glycopeptide antibiotic eremomycin has been elucidated. It is closely related to vancomycin, but differs in sugar and chlorine content. The eremomycin aglycone contains monodechlorovancomycinic acid; the only chlorine atom is situated in the second amino acid after the N-terminal amino acid residue of the peptide. The sugar part is composed of glucose and two residues of an amino sugar shown to be 2,3,6-trideoxy-3-amino-C-3-methyl-L-arabino-hexopyranose (4-epi-vancosamine). One of the amino sugar residues is a component of the disaccharide 2-O-(alpha-L-4-epi-vancosaminyl)-beta-D-glucopyranose, attached to a triphenyl ether moiety; the position of another one is at the serine oxygen in the C-terminal region of the aglycone.

Anti-Bacterial Agents↗
PubMed1989

[Eremomycin--a new antibiotic of the polycyclic glycopeptide group].

Eremomycin is a novel antibacterial antibiotic. It was isolated at the Institute of New Antibiotics, the USSR Academy of Medical Sciences from the culture fluid of actinomycete INA-238. By its physico-chemical and biological properties the antibiotic was classified as belonging to the group of polycyclic glycopeptides. Chemical structure of eremomycin was asserted and it was shown to be a new representative of the group close by its structure to vancomycin and differing from it by the carbohydrate composition and structure of tri-phenoxytriaminotricarboxylic acid. By its anti-bacterial spectrum eremomycin was found to be close to ristomycin and vancomycin. Still, its activity was 2-10 times higher. The antibiotic was several times less toxic than vancomycin. Unlike vancomycin and ristomycin, the novel antibiotic induced no tissue necrosis after its intramuscular administration. The chemotherapeutic indices of eremomycin in treatment of staphylococcal and streptococcal sepsis in albino mice exceeded 10 times those of vancomycin. At present eremomycin is under clinical trials.

Animals↗
PubMed1988

[Determination of carminomycin in its preparations by high-performance liquid chromatography].

A three component system for separating a mixture of carminomycin, carminomycinone and 13-dihydrocarminomycinone by HPLC was developed. Spherisorb ODS Column, 4.6 X 250 mm, the particle size of 10 micron was used. The impact of the mobile phase composition, temperature during chromatography and buffer solution pH on the capacity factors K' for every of the above compounds was studied. For determining purity of carminomycin dosage forms the procedure with an external standard was applied. The procedure provides routine quantitative assay of carminomycin hydrochloride dosage forms.

Buffers↗
PubMed1988

[The antineoplastic antibiotic polypeptide 308 produced by Actinomadura recticatena. Its isolation and physicochemical properties].

A antitumor antibiotic belonging to the group of polypeptide antibiotics containing chromophore was isolated from the culture of Actinomadura recticatena Terekhova, Preobrazhenskaya et Galatenko, 1984, strain 308. Biosynthesis, isolation, physicochemical and biological properties of the antibiotic are described. The results of elemental analysis, the melting point, optical properties, UV, IR and NMR spectra and the data on acid hydrolysis showed that antibiotic 308 was most closely related to antibiotic BBM-928 A.

Actinomycetales↗
PubMed1987

[Eremomycin--a new antibiotic from the cyclic glycopeptide group].

Eremomycin, a novel antibiotic belonging to the group of cyclic glycopeptides is produced by an actinomycete designated INA-238. Biosynthesis, isolation, physico-chemical and biological properties of the antibiotic are described. Eremomycin is shown to be close to vancomycin. However, by its chromatographic and electrophoretic mobility, presence of chlorine in the antibiotic molecule and optic characteristics eremomycin differs from vancomycin. Eremomycin is less toxic than vancomycin whereas its chemotherapeutic activity in treatment of infections caused by gram-positive organisms is higher.

Animals↗
PubMed1986

[Physicochemical properties of octamycin].

Octamycin, an original polyenic antibiotic was developed. The antibiotic is of an amphoteric character. The number and nature of the functional groups were determined by potentiometric titration. It was shown that the antibiotic contained the neutral sugar galactose. The equivalent weight of the antibiotic (990) was measured by potentiometric titration and the content of the sugar in the molecule. With high performance liquid chromatography it was demonstrated that the antibiotic consisted of 2 components at a ratio of 1:2. The molecular weights of the components were evaluated with mass spectrometry.

Anti-Bacterial Agents↗
PubMed1986

[The antibiotic varigomycin--a new representative of the carbonyl-conjugated pentaenes].

In screening new antibiotics, varigomycin produced by a new fungal species Streptomyces variegatus Sveshnikova et Timuk was isolated. By physicochemical properties varigomycin belongs to carbonyl conjugated pentaens. It is a new representative of this antibiotic group. Varigomycin differs from the known representatives of this group by the presence of glucose, sugar in its molecule.

Acylation↗
PubMed1980

[Isolation and physicochemical study of the components of the new antibacterial antibiotic 2562].

An antibacterial antibiotic complex consisting of 2 components designated as 2562 A and 2562 B is produced by Streptomyces griseovarabilis. The antibiotic was isolated from the mycelium and purified chromatographically on a column with aqueous silicic acid. The study of the components showed that component 2562 A was chlorbiocin, while component 2562 B differed from the known antibiotics of this group. Physicochemical assays demonstrated that component 2562 B differed from chlorbiocin by the absence of the methyl group in pyrrol, which is probably attached to sugar at beta-position. It was found that component 2562 B is a new representative of the antibiotic cumero-glycoside group.

Anti-Bacterial Agents↗
PubMed1980

[Structure of carminomycins II and III].

Carminomycins II and III, the main components of the carminomycin complex were isolated in pure state. Their crystalline exalates and acetate of cardminomycin II were prepared. The PMR spectra of both carminomycins and the 13C-NMR spectra of the oxalates were obtained. The molecular weights of the antibiotics were determined by mass-spectrometry. On the basis of the PMR spectra it was shown that carminomycins II and III had similar structures and differed in the stereoisomerism of the nitrogen-free fragment linked to the amino sugar. This was confirmed by the 13C-NMR spectra. The above fragment (C7H15O3) is analogous to the fragment of baumycins A1 and A2 described earlier.

Acetates↗
PubMed1980

[Minor components from the carminomycin complex].

Three components differing by their properties from the carminomycins described earlier were isolated from the carminomycin complex. Comparison of the IR and UV spectra, as well as chromatographic and physicochemical properties of 2 of them showed that they were dihydrocarminomycin and its aglycone or dihydrocarminomycinone, which was prepared earlier by synthesis. The third component was a chromophore belonging to 1,4,6-trihydroxyanthraquinone. Investigation of its IR spectrum, physicochemica properties and PMR spectrum showed it to be carboxymethylethylcarminomycinone identical to epsilon-rodomycinone. The data were confirmed by 13C-NMR spectrometry.

Carubicin↗
PubMed1979

The structure of nocamycin, a new antitumor antibiotic.

The structure of nocamycin, a new antitumor antibiotic, has been elucidated with the aid of mass- and PMR-spectroscopic investigation of the antibiotic and its various chemical transformation products. Nocamycin is structurally related to tirandamycins.

Antibiotics, Antineoplastic↗
PubMed1978

[Formation of the anthracycline antibiotics, beromycin and nogalamycin, by a new actinomycete species, Streptomyces glomeratus sp. nov].

Culture 3980 was isolated from a soil sample and described as a new species, Streptomyces glomeratus sp. nov. It was found that the culture produced simultaneously 2 close anthracycline antibiotics, i. e. nogalamycin and beromycin, which were synthesized mainly in the mycelium. S. glomeratus differed from the nogalamycin and beromycin-producing organisms described earlier.

Anthracenes↗
PubMed1978

[Chromatographic method on a thin sorbent layer for studying the purity and quality of the antitumor antibiotic, rubomycin].

A method for qualitative and quantitative investigation of rubomycin composition was developed. It was based on chromatographic separation of the antibiotic components in a thin layer of silicic acid followed by their elution and spectrophotometric determination. An additional component of rubomycin found in the therapeutic preparations and the conditions of its formation were studied. Fifteen different lots of rubomycin were assayed and the requirements for the limits of the admixtures in the antibiotic therapeutic preparations were determined.

Chromatography, Thin Layer↗
PubMed1977

[Physicochmemical characteristics of the new antineoplastic antibiotic, nocamycin].

Nocamycin is produced by Nocardiopsis syringae. It is recovered from the culture fluid by extraction with chloroform. The molecular weight of the crystalline antibiotic is 503, its melting point is 147--149 degrees, [alpha]20 degrees D = --50 degrees (c. 0.21, chloroform), lambdamax235 and 348 nm(E1%sm= = 150 and 420), the summation formula is C26 H33NO9, the biological activity is 100000 Units/mg with respect to Bacillus mycoides. Nocamycin forms salts with alkalies soluble in water. On hydrolysis with an alkali it forms carbonic acid having no ester bond (IP spectrum) and methoxylic group present in the antibiotic molecule. Nocamycin is a new natural substance.

Antibiotics, Antineoplastic↗