Biomedical subjects

I G Rubezhniak

Publications and source records attributed to I G Rubezhniak.

4 recordsLinked to original sources

PubMedDate not supplied

[Verrucarin A from conidia of Dendrodochium toxicum Pidopl. et Bilai].

A substance which was dyed blue by 4p-(nitrobenzyl)pyridine, that evidenced for its trichotecene nature, has been isolated in the crystalline form from conidia Dendrodochium toxicum Pidopl. et Bilai--roridine H producer. Thin-layer chromatography of the substance in three different systems, the well-known macrocyclic trichotecenes being used as standards, permitted it to be identified with verrucarine A. The substances possessed high biological activity with respect to the indicator test-culture Candida kefyr 900. No other compounds of trichotecene nature were found. Possible role of verrucarine A is discussed.

Chromatography, Thin Layer↗

PubMedDate not supplied

[Changes in the composition of dendrochines in the cultivation dynamics of Dendrodochium toxicum 100115].

The dynamics of change in the component composition of dendrodochines in the process of cultivation of Dendrodochium toxicum 100115 has been studied. It has been shown on the basis of the data of thin-layer chromatography that verrucarines A and J are found during the whole period of the fungus growth. Rhoridines A and E in the initial period of cultivation (1-2 days) are found in trace quantities only. Rhoridine A is found on the 1-3 and 8-10th days of the producer cultivation and its content is inconsiderable only on the 4-6th day. An analysis of qualitative content of the studied verrucarines and rhoridines evidence for its considerable changes in the dynamics of the fungus growth and supposes the reci procal transformation of certain components. The registered processes are accompanied by the change of biological activity of preparations with respect to the used test-objects. A possible mechanism of the producer resistance to its own toxical metabolites is discussed in the light of the data obtained.

Chromatography, Thin Layer↗

PubMedDate not supplied

[Mycotoxins: past, present and future].

The paper deals with historical information concerning the investigation of mycotoxins and mycotoxicoses at the Institute of Microbiology and Virology of the NAS of Ukraine, main results of the works fulfilled for the last 25 years and possible trends of further investigations.

Academies and Institutes↗

PubMedDate not supplied

[The antibiotic properties of the phytotoxic metabolites of Botrytis cinerea Pers].

Antibiotic properties of substances of a phytotoxic complex from Botrytis cinerea have been studied for a number of phytopathogenic bacteria, phytopathogenic and toxigenic fungi as well as saprophytic yeast strains. High fungistatic activity of preparations of phytotoxic metabolites (PTM) has been stated for Dendrodochium toxicum, Myrothecium verrucaria, M. roridum, Aspergillus fumigatus, Penicillium urticae, agents of heavy human and cattle mycotoxicoses. The studied representatives of phytopathogenic fusaria differed significantly in sensitivity to PTM: all the strains studied of the species from section Discolor (Fusarium gibbosum 54,624 and 51,463, F. graminearum 108,269, F. sambucinum 54,968, F. culmorum 54,951) were actively inhibited by the PTM concentrations studied; F. sporotrichiella 52,290 proved to be insensitive to them; the strains studied of the species from sections Elegans (F. oxysporum 55,715, F. moniliforme 54,262) and Martiella (F. javanicum 54,075, F. solani 54,719) possessed different sensitivity to PTM. The overwhelming majority of the yeast strains proved to be resistant to the PTM concentrations studied, except for the strains of Trichosporon cutaneum. In this connection the fact of high sensitivity of one of the strains of Kluyveromyces marxianus var. marxianus to B. cinerea metabolites arouses great interest. The strains of studied phytopathogenic bacteria (Erwinia carotovora subsp. carotovora 8,982 and Clavibacter michiganense 13) were sensitive to higher concentrations of PTM.

Animals↗