Showing papers on "Ribostamycin published in 1975"

Mutational biosynthesis of a new antibiotic, streptomutin A, by an idiotroph of Streptomyces griseus.

Abstract: Microorganisms producing antibiotics have been genetically converted by earlier workers to mutants which cannot produce antibiotic without supplementation with a moiety of the antibiotic. These antibiotics include neomycin, kanamycin, paromomycin, butirosin, sisomicin, ribostamycin and novobiocin. Success has not been reported for organisms producing guanidinocyclitol antibiotics such as streptomycin. We mutagenized conidia of the streptomycin-producing Streptomyces griseus strain 7-455F3 with nitrosoguanidine at pH 7.0. Non-producers of streptomycin were visually selected by the agar-plug technique using Bacillus subtilis. We successfully isolated mutant MIT-A5 which produces no streptomycin unless streptidine is added to the agar medium. The streptidine-dependent phenotype was confirmed in submerged culture in flasks. Attempts to produce new antibiotics by feeding aminocyclitols to mutant MIT-A5 failed. However a new antibiotic (streptomutin A) was produced by supplementation with the guanidinocyclitol, 2-deoxystreptidine. We propose the term "mutational biosynthesis" for the production of new metabolites by the use of mutants blocked in the biosynthetic pathway to the secondary metabolite. We further propose the term "idiotroph" to properly describe such mutants.

Aminoglycoside 3'-phosphotransferase III, a new phosphotransferase. Resistance mechanism

Abstract: The aminoglycoside phosphotransferase of Pseudomonas aeruginosa 21-75 was purified by affinity chromatography using dibekacin-Sephadex 4B or lividomycin A-Sepharose 4B followed by DEAE Sephadex A-50 chromatography. It had activities of both the known aminoglycoside 3'-phosphotransferases I and II, and transferred phosphate from ATP to the 3'-hydroxyl group of kanamycin A, ribostamycin and butirosin A and 5-hydroxyl group of lividomycin A. This enzyme was designated aminoglycoside 3'-phosphotransferase III. It showed strong substrate inhibition by kanamycin A and ribostamycin when their concentration exceeded 6 muM. Purification and characterization of this enzyme are reported.

Bioconversion of ribostamycin (SF-733). II. Isolation and structure of 3-N-acetylribostamycin, a microbiologically inactive product of ribostamycin produced by Streptomyces ribosidificus.

Abstract: The isolation and structure determination of 3-N-acetylribostamycin, a microbiologically inactive derivative, produced enzymatically from ribostamycin by Streptomyces ribosidificus is described. The location of the acetyl group was established by mass and NMR spectrometry of the new compound and its derivatives, and by optical rotation studies conducted on N-ethoxycarbonyl-2-deoxystreptamine. The latter compound was obtained by partial acid hydrolysis of tri-N-ethoxycarbonyl-N-acetylribostamycin.

Process for the synthetic production of 3-deoxy derivative of an aminoglycosidic antibiotic

Abstract: 3'-Deoxy derivatives of neamine, 6'-N-alkylneamine, kanamycin B, 6'-N-alkylkanamycin B, ribostamycin, 6'-N-alkylribostamycin and paromamine may be produced by a new process comprising reducing the 3',4'-α-anhydro derivative (namely, the 3',4'-epoxide derivative) of the aminoglycosidic antibiotics with hydrogen in an alkaline lower alkanol medium containing an alkali metal hydroxide or alkoxide dissolved therein and in the presence of a reducing catalyst such as Raney nickel. The 3',4'-α-anhydro derivative may be prepared by treating the 3'-sulfonylated derivative of the amino-protected and hydroxyl-protected neamine, 6'-N-alkylneamine, kanamycin B, 6'-N-alkylkanamycin B, ribostamycin, 6'-N-alkylribostamycin or paromamine with an alkali metal hydroxide or alkoxide in a lower alkanol to effect epoxidation between the 4'-hydroxyl group and the carbon atom substituted by the 3'-sulfonic ester group.

Neuromuscular blocking properties of some antibiotics in man.

Abstract: Neuromuscular blocking properties of ribostamycin (1gm), dibecacin (100mg) and tobramycin (60mg) were studied in man during anesthesia and surgery by observing the effects of these antibiotics on muscle twitch tension. These drugs alone did not show any neuromuscular blocking action in those therapeutic doses. However, during the recovery phase of d-tubocurarine block the intravenous administration of 1gm of ribostamycin caused a fairly rapid decrease in twitch tension. Tobramycin 60mg did not show any remarkable effect, but dibecacin 100mg produced a slight potentiating effect on the action of d-tubocurarine. The enhancement of the action of dtubocurarine was antagonized promptly by edrophonium and more slowly by calcium.

Bioconversion of ribostamycin (SF-733). III. Formation, structure and synthesis of 3-N-carboxymethyl ribostamycin.

Abstract: A new inactivated product of ribostamycin (SF-733), 3-N-carboxymethyl ribostamycin, was obtained from the broth of Streptomyces ribosidificus which was grown on a medium containing D-xylose. Detection and some biochemical mechanism of N-carboxymethylation were discussed, and structure of 3-N-carboxymethyl ribostamycin was proposed based on the chemical degradation and synthesis.