Showing papers on "Ribostamycin published in 1979"

Biosynthesis of butirosins. I. Biosynthetic pathways of butirosins and related antibiotics.

Abstract: By using 2 neamine-negative mutants, MCRL 5003 and MCRL 5004, of Bacillus circulars, subunit assembly in the biosynthesis of butirosins was investigated. The two mutants were blocked at different steps in the biosynthetic pathway of butirosins, but could produce butirosins when the culture medium was supplemented with neamine. Mutant MCRL 5003 accumulated 2-deoxystreptamine (DOS) in the fermentation broth but could not utilize DOS for the biosynthesis of butirosins, whereas mutant MCRL 5004 could produce butirosins from DOS. Based upon the ability of these 2 mutants to incorporate a series of DOS-containing compounds considered as plausible biosynthetic intermediates of butirosins into butirosins or related antibiotics, the biosynthetic pathways for butirosins and 6'-deamino-6'-hydroxybutirosins were proposed. Feeding experiments with 3', 4'-dideoxy derivatives of neamine, ribostamycin and butirosins supported the pathway proposed for butirosins. A glucosamine auxotroph MCRL 5771 of B. circulars afforded some information as to the role of D-glucosamine in the biosynthesis of butirosins.

[Cross sensitivity between aminoside antibiotics (author's transl)].

Abstract: The great number of topical preparation containing neomycin and their frequent use for a long period induce a lot of contact dermatitis. It is interesting to detect the importance of cross sensitivity between aminosides among the patients whose dermatitis was caused by neomycin. 15 neomycin eczematous patients were investigated. The research about cross-sensitivity concerned 6 antibiotics: streptomycin, framycetin, ribostamycin, gentamycin, kanamycin, tobramycin. Patch-tests (20 p. 100 in petrolatum) were used in order to show this cross-sensitivity. The results of these tests are nearly the same as in the other studies, as for 5 of the antibiotics; but it is the first time, to our knowledge, that a cross-sensitivity between ribostamycin and neomycin is observed. The cross-sensitivity between these two aminosides can be explained by their chemical structure. There are four rings in neomycin: the main components are neamin and neobiosamin. Only three rings are found in ribostamycin: ribostamycin is constitued of neomycin lacking neosamin of neobiosamin. Thus the structure of the 3 rings of ribostamycin is identical with the structure of 3 out of 4 rings of neomycin. The study about cross-sensitivity between aminosides suggests two conclusions: 1. The use of local antibiotics must be prescribed only when is it really necessary. 2. It seems wise to avoid all systemic aminosid antibiotics for patients who are sensitized by neomycin ointment.

[Aminoglycoside-3'-phosphotransferase from Actinomyces fradiae. Its isolation, purification and properties].

Abstract: Aminoglycoside phosphotransferase was isolated from the mycelium of Act. fradiae, the neomycin-producing organism, with paromomycin, neomycin and to a less extent ribostamycin being substrates of aminoglycoside-phosphotransferase. It was purified to homogenous state. The maximum activity of the enzyme preparations was observed at pH 7.7--7.8;KM for neomycin and paromomycin was about 20 micron and KM for ATP was 150 micron. Mg2+ ions were necessary for the enzyme activity. None of the divalent cations tested could replace the magnesium ions in the reaction of phosphorylation catalyzed by the enzyme. High sensitivity to the ionic strength of the buffer was characteristic of the enzyme. It lost about 80 per cent of the initial activity at a concentration of KC1 equal to 1.0 M. The molecular mass of the enzyme from the mycelium of Act. fradiae was determined by the method of gel-filtration through sefadex G-100. It was about 22,000. High stability was characteristic of the enzyme. The fingings indicate that aminoglycoside phosphotransferase from Act. fradiae differs from the described aminoglycoside-3'-phosphotransferases isolated from antibiotic resistant bacteria.

Preparation of novel ribostamycin

Abstract: PURPOSE:To prepare a high ribostamycin by the aerobical cultivation of specific mutant belonging to Bacillus circulans in a nutrient medium. CONSTITUTION:A mutant of Bacillus circulans, B-15M451 (FERM-P No.4320) obtained by the nitrosoguanidine-treatment of Bacillus circulans B-15M-306 which is known ribostamycin-producing bacterium, is inoculated in a nutrient medium, and cultured at pH5.5-8.5 and 20-40 deg.C in an aerated deep-tank fermentor. A large amount of ribostamycin free from xylostasin is accumulated in the medium, and is easily separated from the medium by the extraction with an organic solvent or by the chromatographic treatment with an adsorbent.