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Biomedical subjects

M Kuhn

Publications and source records attributed to M Kuhn.

At least 253 records · Page 14Linked to original sources
PubMed1978

Noboritomycins A and B, new polyether antibiotics.

Noboritomycins A and B, two new polycyclic ionophoric polyethers were isolated from a strain of Streptomyces noboritoensis. The crystal structure and absolute configuration of noboritomycin A were established by X-ray analysis of its silver salt C43/63O14Ag. Noboritomycin A is the first metabolic polyether possessing two carboxylic acid functions on the carbon backbone (C-31), namely a free acid and an additional carboxylic acid ethylester group. An unusual spiroketal system as well as a salicylic acid chromophore represent further remarkable elements. Noboritomycin A shows in this respect a structural relationship to salinomycin and lasalocid respectively. Comparison of physico-chemical data, in particular the interpretation of the 1H- and 13C-NMR spectra, revealed that noboritomycins A and B are structurally closely related, noboritomycin B carrying an ethyl substituent on the aromatic ring in the place of a methyl group present in noboritomycin A. Both metabolites exhibit activity against Gram-positive bacteria and against Eimeria tenella (chicken coccidiosis).

Anti-Bacterial Agents↗
PubMed1977

Mutalomycin, a new polyether antibiotic taxonomy, fermentation, isolation and characterization.

Mutalomycin is a new metal-complexing polyether antibiotic produced by a strain of Streptomyces mutabilis NRRL 8088. The metabolite, a monocarboxylic acid, was isolated as the sodium salt C41H69NaO12. The structure of this polyether was established by X-ray analysis of its potassium salt C41H69KO12. Mutalomycin contains six heterocyclic rings and is structurally related to nigericin. The metabolite is active against gram-positive bacteria and Eimeria tenella (chicken coccidiosis).

Animals↗
PubMed1976

[Demonstration of antibodies to salmonella-R-antigens in sera of patients suffering from salmonelloses (author's transl)].

The extent of hemagglutinating antibody titers against Salmonella R-lipopolysaccharides in 189 sera of 119 human beings suffering from various salmonelloses was estimated. When compared to serum specimens of 137 healthy persons a significant rise in the number of Ra- and Rb2-titer containing sera was observed. It was further found that titers directed against chemotypes Ra, Rb2 and Rc were significantly enhanced in height when compared to the control group. Sera of healthy persons and patients did not show significant differences in Rd1-, Rd2- and Re-titers, respecively. The results indicate that the innermost part of the LPS core in Salmonella S-forms is considerably less (or even none) immunogenic in respect to antibody formation. R-titers in sera from patients suffering from salmonelloses as well as from healthy persons were predominantly directed against Ra-, Rb2- or Rc-LPS structures; the Ra-titer being the most frequent one in both groups. More detailed analyses on sera from patients suffering from salmonelloses revealed a somewhat lower content of R-titers in the early stage of infection. Furthermore in typhoid fever changes in the height of Ra-titers paralled the usual course of O-titers and in gastroenteritic infections the course of illness, respectively. The immunogenicity of the LPS core, however, was less expressed than that of the O-polysaccharides as revealed from a comparison in extent and height of R- and O-titers. Frequently the salmonelloses sera showed titers against several R-antigens. In such cases Ra-titers mostly occurred either together with Rb2-titers alone or concomitantly with both Rb2- and Rc-titers. In absorption experiments it could be demonstrated that two types of antibodies had been formed, those directed against terminal sugar residues in R-lipopolysaccharides and others with specificties against internal partial structures of the core.

Antibodies, Bacterial↗