Glycinothricin, a new streptothricin-class antibiotic from Streptomyces griseus.
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Glycinothricin is a streptothricin-class antibiotic obtained for the first time from the culture broth of a strain of Streptomyces griseus. Glycinothricin, the deformimino derivative of antibiotic LL-AB664, gives N-methylstreptolidine, N-methyl-D-glucosamine and glycine on acid hydrolysis. In comparison with LL-AB664, glycinothricin is less active against gram-positive and gram-negative bacteria and less toxic to mice. (+info)
The effect of racemomycin-D, a nephrotoxic antibiotic, on cellular metabolism of rat kidney cortex in vitro.
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In vitro effects of racemomycin-D on cellular metabolism were examined in rat kidney. Racemomycin-D decreased the concentration gradient of Na+ and K+ across the cell membranes, but failed to influence water content and ATP concentration of kidney cortical slices. The antibiotic inhibited microsomal (Na+ + K+)-ATPase. Preincubation of the microsomes with racemomycin-D enhanced the inhibition about 1.8-fold. Succinoxidase activity of mitochondria remained unaltered in the presence of racemomycin-D, but the antibiotic potently decreased ATP-dependent Ca2+ and Mg2+ uptakes by mitochondria. These results suggest that racemomycin-D probably disorders intracellular homeostasis of Na+, K+ and Ca2+. (+info)
Action of streptothricin F on ribosomal functions.
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The effect of streptothricin F on elongation factor-dependent and on elongation factor-free translation systems was studied. Streptothricin F inhibits factor-dependent as well as factor-free polypeptide synthesis. The results suggest that streptothricin F inhibits polypeptide synthesis via interaction with the ribosome. In partial reactions streptothricin F impairs EF-G-dependent translocation and to a lesser extent EF-Tu-dependent binding of aa-RNA to the ribosome, while it does not affect peptide bond formation significantly. (+info)
Separation and biologic activities of individual components of S15-1, a streptothricin class antibiotic.
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A method is described for isolation of gram quantities of the components of the streptothricin complex S15-1 utilizing CM Sephadex column chromatography eluted with 10% acetic acid as an eluant followed by gradient elution with 10% acetic acid containing 0.02 N approximately 0.03 N HCI. Streptothricins F and E, as well as an unidentified component C1, have been isolated and their comparative biological activities determined. Streptothricins F and E were comparable in taeniacidal activity in mice infected with Hymenolepis nana ia feeding either one at 0.05% in the diet removed 92 approximately 100% of the adult tapeworms. The unidentified component C1 was inactive at the levels tested. In contrast, component C1 was the most active in antimicrobial activity against Bacillus subtilis and in inhibiting the urease activity of proteus mirabilis. In the former test, the ratios of activity were; 1:7:30 for F:E:C1 and in the latter; 1:2:4 for F:E:C1. (+info)
New streptothricin-group antibiotics, AN-201 I and II. Screening, fermentation, isolation, structure and biological activity.
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Two streptothricin-group antibiotics, AN-201 I and II, were newly discovered and isolated from the culture broth of Streptomyces nojiriensis C-13. These antibiotics were purified by IRC-50 (H+) and CM-Sephadex C-50 chromatography, and paper electrophoresis. Structural analysis of AN-201 I and II showed that they were N beta-acetylated derivatives of streptothricin E and D, respectively. They had antibacterial activities against several strains of Escherichia coli, Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus, and showed a strong selective cytotoxic effect on 3T3 cells transformed with SV-40 as compared with their normal cells in a test system in vitro as well as in vivo. (+info)
Nucleotide sequence of the bacterial streptothricin resistance gene sat3.
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The nucleotide sequence of the sat3 gene which encodes resistance of enteric bacteria to the antibiotic streptothricin is reported. A protein with a molecular mass of about 23 kDa is expressed from this gene. The sat3 gene is not obviously related to any one of the streptothricin resistance determinants identified so far among Gram-negative or Gram-positive bacteria. (+info)
Antiviral antibiotic S15-1. Taxonomy of the producing strain and study of conditions for production of the antibiotic.
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Strain S15-1 which produces antiviral antibiotic S15-1 belonging to the streptothricin group of antibiotics was isolated from a soil sample. Cell analysis, colony morphology, the absence of sporangia-like vesicles, the formation of spores in chains of the Rectus Flexibilis type, and the ability to produce melanoid pigment, indicate that this strain belongs to the genus Streptomyces Waksman and Henrici. A comparison of the characteristics of strain S15-1 with related Streptomyces show that it should be identified as Streptomyces purpeofuscus Yamaguchi and Saburi. The investigation of cultural conditions show that soluble starch and meat extract are the most suitable carbon and organic nitrogen sources for the production of antibiotic S15-1. Strain S15-1 grew poorly on media with no organic nitrogen sources, and did not produce the antibiotic. Antiviral antibiotic S15-1 is accumulated at the highest level after 3 or 4 days growth of the producing organism. (+info)
Biosynthesis of streptolidine moiety of streptothricins by Streptomyces noursei JA 3890b.
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The incorporation of uniformly 14C-labeled compounds into the streptothricin-type antibiotic nourseothricin was studied with a strain of Streptomyces noursei JA 3890b. 6.5% of radioactivity from U-14C-L-arginine was incorporated into the antibiotic, while glutamic acid, aspartic acid, alanine, proline, glycine and leucine displayed much lower incorporations. Furhtermore, 95% of the activity incorporated from arginine was located in the streptolidine moiety supporting the suggestion that this subunit of streptothricin antibiotics is formed via the dehydroarginine pathway. (+info)