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Biomedical subjects

F Sztaricskai

Publications and source records attributed to F Sztaricskai.

35 records · Page 2Linked to original sources
PubMed1990

Prof. Rezso Bognár.

Explore the source record for details and available documents.

Anti-Bacterial Agents↗
PubMed1986

13C NMR study of actinoidins: carbohydrate moieties and their glycosidic linkages.

The configuration of the glycosidic linkages and the conformation of the carbohydrate moieties in the molecules of the glycopeptide-type antibiotics actinoidins A and B (1a, 1b) have been determined by means of two-dimensional 13C/1H correlation NMR technique and with the application of model compounds 2-4.

Carbohydrate Conformation↗
PubMed1983

High performance liquid chromatography (HPLC) of antibiotics of vancomycin type. Comparative studies.

Comparative HPLC examination of seven antibiotics of vancomycin type has been undertaken. Investigation has shown that on column I in eluent system B, ristomycin A (ristocetin A) can be not only separated from vancomycin, but both antibiotics can be quantitatively determined. Under these conditions the lowest detectable quantities of the individual antibiotics have been also stated. By the application of this column and eluent system A, ristomycin A (ristocetin A) and the major component of the A-35512 B antibiotic complex can be readily separated from one-another and from avoparcin alpha and beta.

Anti-Bacterial Agents↗
PubMed1980

[Ability of vancomycin-group antibiotics to induce or to inhibit thrombocyte agglutination].

The effect of 4 vancomycin antibiotics on factor VIII-dependent agglutination of thrombocytes was studied. Significant similarity, both quantitative and qualitative, between ristocetin and ristomycin was found. In this connection ristomycin may be used for determination of the so-called ristocetin cofactor. Actinoidin and vancomycin inhibited agglutination of platelets induced by ristocetin or ristomycin in platelet-enriched plasma with citrate or EDTA the same as in the system contaning platelets treated with formalin and did not inhibit agglutination induced by the bovine factor VIII. The 4 antibiotics induced precipitation of the plasma protein. Vancomycin was most active and actinoidin ws lest active in this respect. Ristocetin and ristomycin also possessed such capacity, the effect of the latter being higher. Actinoidin and vancomycin did not prevent the immediate effect of light absorption increasing due to addition of ristocetin or ristomycin to fixed platelets in concentrations completely inhibiting agglutination of platelets in the presence of the protein cofactor. Inhibition of this direct effect of ristocetin and ristomycin was observd only at higher concentrations, which indicated that this effect was not probably associated with agglutination. The results of the study on various ristomycin derivatives showed that methylated carboxylic groups and free hydroxyls of phenol may play the main role in ristomycin binding with the thrombocytic membrane and/or protein cofactor.

Dose-Response Relationship, Drug↗
PubMed1979

Structural investigation of the antibiotic ristomycin A. The amino acid constituents.

Hydrolysis of the O-methylated aglycone of ristomycin A by a mixture of KOH and NaBH4 yielded a mixture of aromatic amino acids which, after N-acetylation and O-methylation, were separated by chromatography on silica gel. Compounds III approximately VII were isolated and identified by pmr and mass spectroscopy. Compounds V approximately VII were also oxidatively degraded to the corresponding benzoate esters. Componds III and IV are derived from ristomycinic acid (I) and V from actinoidinic acid (II), both of which had been obtained in earlier acid hydrolyses of the antibiotic. Compounds VI and VII had not been detected previously nor glycine which was also found to be a product of base hydrolysis. It is postulated that the new products arise from bisdechlorovancomycinic acid (X). It is concluded that aglycoristomycin A comprises I, II and X which also constitute the aglycone of ristocetin A.

Amino Acids↗
PubMed1978

Structural investigation of the antibiotic ristomycin A. 13C-NMR spectral analysis of the interglycosidic linkages of the heterotetrasaccharide side-chain.

By 13C-NMR studies on Ia, IIa, IIb and IVa obtained by the chemical degradation of ristomycin A and on several synthetic model compounds it has been proved that an O-beta-D-arabinopyranosyl-(1 leads to 2)-O-alpha-D-mannopyranosyl-(1 leads to 2)-O-[alpha-L-rhamnopyranosyl-(1 leads to 6)]-D-glucopyranosyl heterotetrasaccharide moiety is connected to the aglycone of the antibiotic.

Chemical Phenomena↗
PubMed1976

Structural investigation of the antibiotic ristomycin A. Synthesis of ristobiose and ristotriose.

Proof is given by synthesis confirming the structure of ristobiose as 2-O-alpha-D-mannopyranosyl-D-glucose (IV) and ristotriose as O-alpha-L-rhamnopyranosyl (1 leads to 6)-O-[alpha-D-mannopyranosyl (1 leads to 2)]-D-glucose (X) which are obtained from ristomycin A upon mild acid hydrolysis. Both oligosaccharides, IV and X, have been detected for the first time as the components of an antibiotic.

Hydrolysis↗