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1.
Antibiot Khimioter ; 51(2): 8-12, 2006.
Article in Russian | MEDLINE | ID: mdl-16878386

ABSTRACT

A simple and reliable HPLC method for quantitative analysis of complex antibiotics consisting of a mixture of streptothricins F, E, D and C in a biological matrix was developed. The method is based on ion-pair separation of streptothricins on the reversed-phase C18 analytical column with UV detector (210 nm). Aqueous solution of acetonitrile containing trifluoroacetic acid and octane-1-sulfonic acid sodium salt was used as eluent. Retention times of streptothricins became longer as the molecular weight increased, i.e. the component F was eluted first, then followed components E, D and C. The total time of the analysis was ca. 22 min. Composition of the standard samples of nourseothricin and grisin, as well as the streptothricin content of the commercial grisin-based kormogrisin were determined. Components F and D were found to be dominant in the streptothricin complex comprising totally 70-90%, with streptothricin F prevailing in nourseothricin (56%) and streptothricin D being the major constituent in grisin (51%), while in the kormogrisin the concentrations of components D and F were approximately the same. The portion of E varied from 5 to 20% and the concentration of streptothricin C changed within the range of 3-11%. The peaks of the admixtures present in kormogrisin did not interfere with determination of the streptothricin components. It is suggested that the method described can be applied to determination of the streptothricins in biological objects without a complex preliminary sample preparation.


Subject(s)
Chromatography, High Pressure Liquid/methods , Streptothricins/analysis , Streptothricins/chemistry , Chromatography, High Pressure Liquid/instrumentation
2.
Antibiot Khimioter ; 49(5): 8-10, 2004.
Article in Russian | MEDLINE | ID: mdl-15573897

ABSTRACT

The effects of the natural avermectin complex, aversectin C and individual avermectin B1 on the growth of ascitic and solid transplantable tumors in animals were studied. The results showed for the first time that both aversectin C and avermectin B1 possessed marked antitumor activity. In subtoxic doses aversectin C significantly inhibited the growth of P388 lymphoid leukemia and Ehrlich carcinoma, both ascitic and solid ones. In some administration regimens aversectin C inhibited the tumor growth by 70 to 80%. The highest effect of aversectin C was observed after its intraperitoneal administration. Avermectin B1 inhibited the growth of solid Ehrlich carcinoma and carcinoma 755.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Ehrlich Tumor/drug therapy , Ivermectin/analogs & derivatives , Ivermectin/pharmacology , Leukemia P388/drug therapy , Administration, Oral , Animals , Antineoplastic Agents/administration & dosage , Carcinoma, Ehrlich Tumor/pathology , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Injections, Intraperitoneal , Injections, Subcutaneous , Ivermectin/administration & dosage , Leukemia P388/pathology , Male , Mice
3.
Antibiot Khimioter ; 49(6): 3-5, 2004.
Article in Russian | MEDLINE | ID: mdl-15628794

ABSTRACT

The effect of avermectins (aversectin C, aversectin C1 and avermectin B1) on the vincristine antitumor action with respect to murine transplantable tumors was studied. It was shown that both the natural avermectins mixtures and the individual avermectin B1 potentiated the antitumor action of vincristine on Ehrlich carcinoma, melanoma B16 and P388 lymphoid leukemia, including the vincristine resistant strain P388. Such an effect of the avermectins was observed only when they were administered after vincristine.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Neoplasms, Experimental/drug therapy , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Antiparasitic Agents/administration & dosage , Dose-Response Relationship, Drug , Ivermectin/administration & dosage , Ivermectin/analogs & derivatives , Mice , Mice, Inbred DBA , Neoplasm Transplantation , Vincristine/administration & dosage
4.
Antibiot Khimioter ; 47(12): 6-10, 2002.
Article in Russian | MEDLINE | ID: mdl-12728628

ABSTRACT

Degradation rates and compositional changes in active ingredients of the two crop protection insecticides, Fitoverm and Spinosad, have been compared by using a reverse-phase HPLC with UV detection (250 nm). Decay of the major components of active ingredients: spinosyns A and D (Spinosad) and avermectins A1a, A2a, B1a and B2a (Fitoverm) was studied in the thin dry layer on the glass at sunlight at regular day/night changes of temperature. The following results were obtained: 1) 50% degradation time for spinosyns was about two times shorter than that for avermectins: at 40 degrees C day-time temperature it was 6 hours and 10 hours, respectively, while at 23 degrees C these times increased approx. ten-fold; 2) the initial composition of spinosyns was changed during degradation: ratio of spinosyns A/D was increased (i.e. D component degraded faster than the A one) and additionally 4-5 new spinosyns and/or their derivatives were formed; 3) rate of degradation of each avermectin was practically the same, i.e. percent composition of avermectins did not significantly alter; 4) retention times of avermectins B2a, A2a and A1a were similar to those of either initial spinosyns (A) or products of their decay. It is concluded that determination of spinosysn residues with the aid of UV-HPLC is a complex task since both initial spinosyns (A and D) and their conversion/decay products must be measured. The latter can be dominant residues and not always easy to identify. Analysis consider to be complicated when a sample contains residues of both spinosyns and avermectins.


Subject(s)
Anti-Bacterial Agents/chemistry , Chromatography, High Pressure Liquid/methods , Insecticides/chemistry , Ivermectin/analogs & derivatives , Ivermectin/chemistry , Spectrophotometry, Ultraviolet/methods , Kinetics , Macrolides
5.
Eksp Klin Farmakol ; 64(2): 64-6, 2001.
Article in Russian | MEDLINE | ID: mdl-11548452

ABSTRACT

The acute oral, cutaneous, and inhalation toxicity of aversectin C was studied on white unbred rats and mice. The compound was less toxic for rats than for mice, the LD50 for oral administration being 90 and 33 mg/kg, respectively. Aversectin C exhibited a maximum acute toxicity upon the inhalation in rats (LD50 = 40 mg/kg), while a minimum toxicity level was observed for the cutaneous application in rats (1700 mg/kg).


Subject(s)
Antiparasitic Agents/toxicity , Ivermectin/toxicity , Pesticides/toxicity , Administration, Inhalation , Administration, Oral , Administration, Topical , Animals , Antiparasitic Agents/administration & dosage , Dosage Forms , Female , Ivermectin/administration & dosage , Ivermectin/analogs & derivatives , Lethal Dose 50 , Male , Mice , Rats , Toxicity Tests, Acute
6.
Antibiot Khimioter ; 46(5): 13-6, 2001.
Article in Russian | MEDLINE | ID: mdl-11558448

ABSTRACT

A natural avermectin complex, aversectin C, was shown to be capable of exerting selective cytostatic effect. It killed proliferating neuroblastoma B 103 cells but was non-toxic for differentiated cells of this culture. The activity of aversectin C was related neither to activation of the GABA alpha-receptors nor to their blocking and was at a large extent due to the action of avermectin A1, a component of aversectin C.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Ivermectin/pharmacology , Animals , Antibiotics, Antineoplastic/toxicity , Cell Death , Cell Differentiation , Cell Division , Ivermectin/analogs & derivatives , Ivermectin/toxicity , Rats , Tumor Cells, Cultured
7.
Antibiot Khimioter ; 46(5): 6-12, 2001.
Article in Russian | MEDLINE | ID: mdl-11558454

ABSTRACT

A natural complex of avermectins, aversectin C, and a component of this complex, avermectin A1, were shown to change the conductivity of Ca(2+)-dependent chloride channels of plasmalemma of Chara corallina cells by acting only from the outer side of the cellular membrane. Low concentrations of aversectin C and avermectin A1 increased the chloride current: K1/2 = 3.5 x 10(-5) mg/ml for the whole complex and K1/2 = 2.1 x 10(-3) mg/ml for A1. Relatively high concentrations of the compounds suppressed the chloride current: K1/2 = 2.2 x 10(-3) mg/ml for aversectin C and K1/2 = 4.2 x 10(-6) mg/ml for A1. The Hill coefficients for the interaction of avermectin A1 with the corresponding targets for stimulation and suppression of the chloride current were 2.8 and 2.5 respectively. Bicuculine, a non-specific inhibitor of the GABA alpha-receptors, did not influence stimulation of chloride currents caused by action of low concentrations of avermectins, but at the same time blocked suppression of the chloride currents associated with the action of high doses of avermectins. Avermectins A2, B1 (abamectin), B2 and 22,23-dihydroavermectin B1 (vermectin) in the concentration range studied, did not affect the chloride currents of Chara corallina cells.


Subject(s)
Calcium/metabolism , Cell Membrane/physiology , Chloride Channels/drug effects , Chlorides/metabolism , Ivermectin/pharmacology , Chloride Channels/metabolism , Chlorides/physiology , Dose-Response Relationship, Drug , Electrophysiology , Eukaryota , Ivermectin/analogs & derivatives , Patch-Clamp Techniques
8.
Morfologiia ; 120(6): 24-6, 2001.
Article in Russian | MEDLINE | ID: mdl-12016760

ABSTRACT

The effect of natural avermectin complex (Aversectin C) and Abamectin on the processes of proliferation and morphological differentiation of the neural cells was studied using N1E-115 murine neuroblastoma cells (clone C-1300) as a model. Aversectin C in concentrations 10(-7)-10(-8) was shown to induce morphological differentiation of cultured nervous cells. Treatment with Abamectin resulted in the changes of proliferation pattern of the cells. Morphological differentiation of the cultured nervous cells treated with Aversectin C was associated with electrophysiological one.


Subject(s)
Cell Division/drug effects , Ivermectin/analogs & derivatives , Ivermectin/pharmacology , Neuroblastoma/pathology , Animals , Cell Differentiation/drug effects , Mice , Tumor Cells, Cultured
9.
Antibiot Khimioter ; 45(10): 10-4, 2000.
Article in Russian | MEDLINE | ID: mdl-11212393

ABSTRACT

Effect of natural avermectin complex (aversectin C) and separate avermectins A1, A2, B1 and B2 in the cell culture of murine myeloma Ns/o, Erlich carcinoma ascites and human larynx carcinoma Hep-2 was investigated. It was shown that aversectin C within the concentrations of 0.1 to 1.0 mcg/ml inhibited proliferation of tumor cells and induced their death. Proliferation inhibition was due to the delay of the cells cycle start (lag-phase prolongation) and blocking of mitotic cycle. Ns/o cells death had apoptosis signs: chromatin condensation and fragmentation, DNA fragmentation. It was demonstrated that only avermectin A1 has cytotoxic activity within the concentrations used, avermectins A2 and B2 had cytostatic activity, avermectin B1 showed no activity under the experimental conditions.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Ivermectin/analogs & derivatives , Ivermectin/pharmacology , Animals , Carcinoma, Ehrlich Tumor , Cell Division/drug effects , Humans , Laryngeal Neoplasms , Mice , Multiple Myeloma , Neoplasms, Glandular and Epithelial , Tumor Cells, Cultured
10.
Antibiot Khimioter ; 44(7): 16-20, 1999.
Article in Russian | MEDLINE | ID: mdl-10494378

ABSTRACT

Aversectin C was evaluated for mutagenic activity in the Ames test with Salmonella typhimurium TA 97, TA 98 and TA 100, in the dominant lethal assay on uninbred albino rats in a dose of 2.25 mg/kg body weight (1/40 of the LD50) and in the metaphase test on F1CBAxC57BI/6 mice in a dose of 8.2 mg/kg body weight (1/5 of the LD50). The agent showed no mutagenic activity in any of the tests. The anaphase test on F1CBAxC57BI/6 mice revealed no antimitotic activity of aversectin C.


Subject(s)
Anti-Bacterial Agents/toxicity , Ivermectin/analogs & derivatives , Mutagens/toxicity , Anaphase/drug effects , Animals , Bone Marrow Cells/drug effects , Ivermectin/toxicity , Lethal Dose 50 , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mitosis/drug effects , Mutagenicity Tests , Rats , Salmonella typhimurium/genetics
11.
Antibiot Khimioter ; 44(6): 16-20, 1999.
Article in Russian | MEDLINE | ID: mdl-10422573

ABSTRACT

Avermectins are final products in the fermentation process with Streptomyces avermitilis. They have parasitocidic activity and are used as the main substances of insectoacaronematocides. The study of the activity of the natural avermectin complex (aversectin C) and separate avermectins A1, A2, B1 and B2 in the cell culture of lymphoid leukemia P-388 showed that within the concentrations of 0.1 to 1.0 microgram/ml aversectin C inhibited the growth of the tumor cells and induced their death. The inhibition was due to blocking the cell mitosis. The cell death was accompanied by internucleosomal degradation of the DNA nuclei i.e. the death was of the apoptosis type. The sensitivity of the cells to aversectin C was directly proportional to their initial proliferative activity. As for the separate avermectins only avermectin A1 had the cytotoxic activity within the concentrations used, avermectin A2 had the cytostatic activity and avermectins B1 showed no activity under the experimental conditions.


Subject(s)
Antineoplastic Agents/therapeutic use , Antiparasitic Agents/therapeutic use , Insecticides/therapeutic use , Ivermectin/analogs & derivatives , Leukemia, Lymphoid/drug therapy , Streptomyces/metabolism , Animals , Drug Screening Assays, Antitumor , Ivermectin/therapeutic use , Male , Mice , Mice, Inbred DBA , Tumor Cells, Cultured
13.
Prikl Biokhim Mikrobiol ; 27(6): 838-44, 1991.
Article in Russian | MEDLINE | ID: mdl-1796092

ABSTRACT

The monosporic plating of the avermectin-producing strain Streptomyces avermitilis VKM Ac-1301 with low activity showed the heterogeneity of the population. By selection of natural mutants the authors obtained a strain synthesizing up to 60 micrograms avermectin B1 per ml of culture liquid. The maximum avermectin yield was observed in the medium containing 7% glucose after 100-120 h of culture growth.


Subject(s)
Ivermectin/analogs & derivatives , Streptomyces/metabolism , Culture Media , Glucose/metabolism , Ivermectin/metabolism , Streptomyces/growth & development
14.
Antibiot Khimioter ; 34(1): 16-9, 1989 Jan.
Article in Russian | MEDLINE | ID: mdl-2730210

ABSTRACT

The medium redox potential had an effect on gentamicin production by Micromonospora purpurea v. violacea, strain VNIIA 7R. The Eh influence was shown to be statistically reliable when the results were expressed in relative units against the control. In the laboratory experiments with low volumes of the medium the Eh increase by more than 170 per cent induced inhibition of gentamicin biosynthesis while the Eh increase by 108 to 168 per cent induced stimulation of the activity.


Subject(s)
Gentamicins/biosynthesis , Culture Media , Electrolysis , Micromonospora/metabolism , Oxidation-Reduction
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