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Iu V Dudnik

Publications and source records attributed to Iu V Dudnik.

At least 19 recordsLinked to original sources
PubMed2003

[Antimicrobial activity of Laetiporus sulphureus strains grown in submerged culture].

Cultural conditions for growth and fruit body formation were elaborated to four strains of Laetiporus sulphureus isolated from nature. All strains demonstrated antimicrobial activity against a wide spectrum of gram-positive and gram-negative bacteria during agar and submerged cultivation including methicillin-resistant strain of Staphylococcus aureus (MRSA) and glycopeptide-resistant strain of Leuconostoc mesenteroides. Antifungal activity was not found. The level of antimicrobial activity during submerged cultivation reached maximum after seven days of growth on specific medium with soybean meal and corn liquid; the next four weeks its increasing was not so manifested. Antimicrobial activity correlated with orange pigment secretion and cultural liquid acidification to pH 2.0-2.8 that indicates on acid nature of synthesized products.

Anti-Bacterial Agents↗
PubMed2003

[A-Factor as a selective agent for isolation of the soil Gram-negative bacterium strain--the producent of an antibacterial antibiotic].

It was shown the stimulating role of A-factor on soil prokaryotes growth. Soil sample culturing on agar medium, containing A-factor, resulted in the colony forming units (CFU) increasing in comparison with culturing on the medium without this regulator. Gram-negative bacteria were the reason of CFU increasing; previously the effect of A-factor on bacteria of this group was not shown. Gram-negative rod bacterial strain No. 35 was isolated and shown that CFU number was approximately twice increased at A-factor concentration in agar medium 2 and 7 mcg/ml; high A-factor concentration up to 28 mcg/ml was not effective. Isolated strain No. 35 is the producer of antibiotic, effective against gram-positive bacteria.

4-Butyrolactone↗
PubMed2001

[Increase in eremomycin production by regeneration and UV-irradiation of Amycolatopsis orientalis subsp. eremomycini protoplasts].

Protoplast regeneration of Amycolatopsis orientalis subsp. eremomycini producing eremomycin leads to the change of cultural and morphological properties as well as synthesis of secondary metabolites. Formation of plus-variants with enchanced antibiotic production was promoted by UV-irradiation of protoplasts. These plus-variants can be successfully used for repeating protoplasting--UV-irradiation of protoplasts with further increasing of the strain productivity. Finally activity of the initial A. orientalis culture was increased 7-8 times. Proposed method is recommended for the improvement of actinomycetes strains producing antibiotics especially in the case of cultures with poor sporulation.

Actinomycetales↗
PubMed2000

[The hypolipidemic action of antibiotic 86/88 (enniatin B) in a hepatoblastoma G2 cell culture].

A cyclodepsipeptide antibiotic 86/88 (enniatin B) with strong hypolipidemic action was isolated from the culture liquid of the fungus INA F-86/88 identified as Fusarium lateritium Nees var. stilboides (Wr.) Bilai. In the Hep G2 cell culture the antibiotic suppressed 14C-acetate incorporation into cholesterol (IC50 1.75 microM), cholesterol ethers (IC50 1 microM), triglycerides (IC50 1.3 microM) and free fatty acids (IC50 2.2 microM). The most pronounced effect of the drugs, i.e. the suppression of the cholesterol ethers synthesis is likely due not only to the ACAT inhibition but also to the inhibition of the triglyceride synthesis and the diminishing of the free fatty acids pool in the cells.

Anti-Bacterial Agents↗
PubMed1999

[The cytotoxicity of mevalonate, lovastatin and carminomycin with respect to MOLT-4 human malignant T-lymphoblasts in vitro].

It was shown in vitro that high concentrations of lovastatin, a competitive inhibitor of hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase inhibited human malignant cells MOLT-4. The activity of lovastatin in doses of 50-250 microM was dose-dependent. Addition of mevalonate in a concentration of 3 mM to the growth medium completely prevented the cytotoxic effect of 100 microM of lovastatin. At the same time, exogenous mevalonate did not decrease the cytotoxicity of the anthracycline antibiotic carminomycin. Moreover, in a high concentration (7 mM) mevalonate slowly but significantly inhibited the growth of the malignant target cells and the effect was added to the cytotoxic effect of carminomycin low concentrations (0.08 to 0.175 microgram/ml). The results and the literature data suggested that combination of mevalonate, HMG-CoA reductase inhibitors and anthracyclines could be useful in tumor chemotherapy. The suggestion needs further investigation.

Antibiotics, Antineoplastic↗
PubMed1995

[Induction of antibiotic formation by inactive cultures of actinomycetes. A mutant strain of Streptomyces helvaticus, a new producer of bruneomycin].

After exposure of an inactive actinomycete to ethidium bromide a stable mutant producing an antibiotic on a solid medium was isolated. The exposure to methylnitrosoguanidine provided the isolation of a more productive variant synthesizing the antibiotic in a liquid medium. By UV, IR, NMR and mass spectroscopy the antibiotic was identified as bruneomycin (streptonigrin). The taxonomic investigation of the culture showed that it belongs to Streptomyces helvaticus which is a new culture producing bruneomycin (streptonigrin). Previously it did not synthesize the antibiotic.

Antibiotics, Antineoplastic↗
PubMed1995

[Induction of antibiotic production in inactive cultures of actinomycetes. Monensin production by a mutant strain 2608 EB-1].

An actinomycete strain designated as 2608 was isolated from a soil sample. When cultivated on various solid and liquid media, the strain was inactive. The strain exposure to ethidium bromide resulted in formation of a mutant producing an antibiotic active against some gram-positive bacteria. The property of the antibiotic production proved to be stable. The antibiotic was identified by IR, NMR and mass spectroscopy as monensin. Strain 2608 producing monensin differs from the described monensin-producing culture Streptomyces cinnamonensis ATCC 15413 and is a new culture producing monensin.

Actinomycetales↗
PubMed1993

[Use of the protoplast fusion and regeneration method for screening antibiotic producers among inactive strains of Streptomyces].

Intraspecies fusion of protoplasts of two strains of Streptomyces fradiae, i.e native protoplasts of an inactive strain INA 00708 and heat inactivated protoplasts of a neomycin-producing strain ATCC 10745, and regeneration of the protoplasts of the inactive strain INA 00708 resulted in formation of clones producing neomycin and clones synthesizing antibiotics of an unknown nature differing from neomycin. All the active clones were unstable and lost their antibiotic activity in subcultures. Regeneration of the protoplasts of 4 different inactive strains of Streptomyces sp. also resulted in formation of active clones which were unstable and lost their capacity for the antibiotic synthesis after the first subculture. The data in principal indicate to the possible use of protoplast fusion and regeneration in screening of cultures producing new antibiotics among inactive strains of streptomycetes. However, the efficiency of such procedures is low since the experiments are labor-consuming and the resulting active clones are genetically unstable.

Anti-Bacterial Agents↗
PubMed1992

[Protoplast fusion in Streptomyces fradiae strains producing neomycin and tylosin].

Interspecies fusion of protoplasts of the Streptomyces fradiae strains producing neomycin (an aminoglycoside antibiotic) and tylosin (a macrolide antibiotic) was performed with a view to isolate strains producing novel antibiotics. Fusion of the protoplasts of the neomycin- and tylosin-producing strains labelled by the resistance to monomycin and lincomycin, respectively, caused no formation of stable strains producing antibiotics differing in chromatographic mobility from the antibiotics produced by the initial strains. In fusion of the protoplasts of the unlabelled strains, heat-inactivated protoplasts of the active line of one strain (donor) and native protoplasts of the inactive line of the other strain (recipient) were used. When the neomycin-producing culture was used as a recipient the fusion led to formation of strain 195-34 producing antibiotics of the benzo(a)anthraquinone group. One of these antibiotics, i.e. antibiotic 34-I, proved to be a novel biologically active substance. After regeneration of the protoplasts of the initial strains, no stable strains producing antibiotics differing from neomycin and tylosin were isolated.

Drug Resistance, Microbial↗
PubMed1992

[Comparative study of Streptomyces--producer of aminoglycoside antibiotics, monomycin and kanamycin, and the strain 344 obtained by fusion of their protoplasts by the method of restrictive total DNA fingerprinting].

The method of total DNA restriction finger prints was applied to the study of Streptomyces monomycini INA 1465 producing monomycin, Streptomyces kanamyceticus INA K-13 producing kanamycin and strain 344 isolated after fusion of the protoplasts of strain 1465 and K-13, which produced albofungin and chloralbofungin, aminoglycoside antibiotics. For preparing the finger prints of the strains splitting by endonucleases BamHI, PstI, PvuII, and BgIII was used. The finger prints showed that strain 344 was related to the strain of S. monomycini and markedly differed from the strain of S. kanamyceticus. Strain 344 was likely to result from reconstruction (probably 20-kb deletion) of the genome of S. monomycini INA 1465 induced by the preparation and regeneration of its protoplasts. The reconstruction could affect the genome area with localization of the genes involved in monomycin biosynthesis and monomycin resistance genes.

Cell Fusion↗
PubMed1991

[Albofungin formation by a strain isolated as a result of fusion of protoplasts of organisms producing aminoglycoside antibiotics].

Strain 344 synthesizing an antibiotic complex was isolated after fusion of the protoplasts of Streptomyces monomycini producing monomycin and Streptomyces kanamyceticus producing kanamycin. The major component of the complex was identified with albofungin and the minor one was suggested to be chloralbofungin. In the cultures of strain 344 variants forming monomycin were detected. After regeneration of the protoplasts of the parent strains there were isolated no stable clones synthesizing antibiotics differing from monomycin and kanamycin.

Anti-Bacterial Agents↗
PubMed1988

[Transformation of anthracycline antibiotics and their semisynthetic derivatives as affected by the liver aldo-keto reductase of rats].

Formation of 13-dihydro derivatives of rubomycin (daunorubicin), carminomycin, doxorubicin and some of their semisynthetic derivatives under the effect of pure aldo-keto reductase from the rat liver was studied. Attachment of an oxy group to C-14 markedly retarded formation of the 13-dihydro derivatives while attachment of the bulky radicals to the same position prevented their formation. Binding of the anthracycline antibiotics to human serum albumin had no impact on the fermentative reaction rate. Rubomycin, carminomycin and doxorubicin significantly differed in their lipophilic properties and capacity for binding to serum albumin.

Alcohol Oxidoreductases↗
PubMed1988

[Semisynthetic derivatives of daunorubicin and carminomycin: inhibition of DNA synthesis after intravenous administration to mice].

Inhibition of DNA synthesis in the liver, kidneys, spleen and heart of mice after intravenous administration of 0.1 and 0.3 LD50 of semisynthetic derivatives of rubomycin (daunorubicin) and carminomycin was studied. The level of DNA synthesis inhibition was estimated by a decrease in incorporation of (methyl-3H) thymidine. Under the action of 13-trebutoxycarbonyl hydrazone and 14-salicyloiloxy derivatives of rubomycin and carminomycin maximum inhibition of DNA synthesis was reached later while its recovery started earlier as compared to the initial antibiotics.

Animals↗
PubMed1988

[Suppression of DNA synthesis in mice by the anthracycline antibiotics daunorubicin, carminomycin and doxorubicin].

Inhibition of DNA synthesis by rubomycin (daunorubicin), carminomycin and doxorubicin in the spleen, liver, kidneys and heart was studied on mice. The antibiotics were administered intravenously in a dose of 0.3 LD50. The inhibition level was estimated by incorporation of 3H-thymidine. The time courses of DNA synthesis inhibition by daunorubicin, carminomycin and doxorubicin markedly differed, whereas the patterns of their inhibition curves for all the organs were close. The maximum inhibition of DNA synthesis by carminomycin was observed in 6 hours. After that period it gradually restored. Doxorubicin induced the maximum inhibition of DNA synthesis in 24-48 hours after its administration. Daunorubicin induced two maxima in inhibition of DNA synthesis i. e. in 6 and 48 hours. Definite correlation between the levels of DNA synthesis inhibition by the antibiotics and their toxic action was shown.

Animals↗