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Biomedical subjects

I V Konova

Publications and source records attributed to I V Konova.

At least 19 recordsLinked to original sources

Glycolipids of the filamentous fungus Absidia corymbifera F-295.

The lipids extracted with CHCl(3)/MeOH mixtures from mycelium of the lower filamentous fungus Absidia corymbifera F-295 were found to contain three glycolipids. Based on the IR, 1H and 13C NMR spectra, plasma-desorption ionisation (PDI) mass spectra as well as chemical degradation results, the glycolipids were established to be 1-O-beta-D-glucopyranosyl-2-N-(2'-D-hydroxyhexadecanoyl)-9-methylsphinga-4(E),8(E)-dienine (glucosyl ceramide) and 2-O-(6'-O-beta-D-galactopyranosyl)-beta-D-galactopyranosides of 2-D-hydroxy and erythro-2,3-dihydroxy fatty acids C(9), C(11), and C(13). They accounted for about 3.4, 0.8, and 0.4%, respectively, of the total lipids extracted. No lipids identical to the above monohydroxy and dihydroxy fatty acid glycosides have been reported.

Absidia↗

Unusual fatty acid composition of cerebrosides from the filamentous soil fungus Mortierella alpina.

The cerebrosides produced by the soil filamentous fungus Mortierella alpina strain KG-1/95 account for about 13% of the total polar lipids extractable from lyophilised cells with chloroform/methanol mixtures. By means of 1H NMR and (13)C NMR spectroscopy, matrix-assisted laser-desorption ionisation mass spectrometry, and chemical degradation experiment, they have been shown to be 1-O-beta-D-glucopyranosyl-2-N-(2'-D-hydroxyalkanoyl)-9-methylsphinga-4(E),8(E)-dienines, the fatty acid composition of which is unusual and consists of 2-hydroxytridecanoic (4%), 2-hydroxytetradecanoic (60%), 2-hydroxypentadecanoic (20%), and 2-hydroxyhexadecanoic (16%) acids.

Cerebrosides↗

Two unusual glycerophospholipids from a filamentous fungus, Absidia corymbifera.

The chloroform-methanol extractable lipids of the soil filamentous fungus Absidia corymbifera VKMF-965 account for about 20% by weight of dry cells and are composed of low-polarity constituents (about 75% of the total lipids), such as triacylglycerols (mainly), diacylglycerols, sterols and free fatty acids, as well as of glycolipids (about 3%) and phospholipids. The last consist largely of components common to the fungal lipids, namely, phosphatidylethanolamine (38% of the total phospholipids), phosphatidyl-myo-inositol (16%), diphosphatidylglycerol (12%), phosphatidylcholine (7%), phosphatidic acid (6%) and phosphatidylglycerol (3%), and two unusual phospholipids, PL1 (6%) and PL2 (9%). Based on the infrared (IR), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectra along with the results of degradation experiment, these two phospholipids have been established to be 1,2-diacyl-sn-glycero-3-phospho(N-acetylethanolamine), or N-acetyl phosphatidylethanolamine, and 1,2-diacyl-sn-glycero-3-phospho(N-ethoxycarbonyl-ethanolamine), respectively. These structures have been confirmed by preparing similar phospholipids from the phosphatidylethanolamine isolated from the same fungus and correlating their chromatographic behaviour, IR and (1)H-NMR spectra with those of PL1 and PL2. So far N-acetyl phosphatidylethanolamine has been detected only in cattle and human brains and a human placenta but its structure was not rigorously proved. PL2 is a novel lipid; to our knowledge no natural phospholipid with an urethane group has yet been found. The main fatty acids of both the phospholipids are n-hexadecanoic, octadecanoic and octadecadienoic ones; PL2 contains in addition a considerable amount of octadecatrienoic acid with its greater portion located at the sn-1 position.

Absidia↗

[Body's responsiveness and postoperative course in patients with pulmonary tuberculosis].

The purpose of the study was to reveal a package of criteria for the body's responsiveness in order to predict the course of a postoperative period in 25 patients with short-term pulmonary tuberculosis. The indices of the responsiveness were comparable with the specific features of a postoperative course. The study of the body's responsiveness prior to surgery and in the first days after it was found to be of value in the prediction of a postoperative course. The determination of the intensity of free radical processes may more accurately estimate the impact of surgical interventions on the body's responsiveness. The drastic rise in the activation of free radical oxidation after surgery suggests its unfavourable influence on immune mechanisms.

Autoimmunity↗

[Lipids of initial and mutant cultures of Penicillium chrysogenum, producers of penicillin].

Comparative investigation of lipogenesis in 2 initial and 4 mutant strains of Penicillium chrysogenum showed that there were no noticeable differences in the composition of the lipid fatty acids in these strains. Certain shifts in the ratio of definite lipid fatty acids in the mutant strain deficient by synthesis of lysine and isoleucine (increased contents of oleic acid) were revealed. A marked influence of the physiological conditions on lipogenesis in the mutant with multiple deficiency by amino acids, vitamins and nucleotides was observed.

Fatty Acids↗

[Fatty acid composition of Fusidium coccineum lipids].

The fatty acid composition of the lipids synthesized de novo or during growth of the organism producing fusidic acid, Fusidium coccineum on complex media was studied. The content of the total extractable lipids in the mycelium did not exceed 10-11 per cent ty the biomass dry weight. Unsaturated fatty acids with 18 carbon atoms in the chain, mainly oleinic and linoleic acids and saturated fatty acids such as palmitic and stearic acids predominated. The ratio of the main fatty acids and the content of the minor acids were subject to strains and conditions of their cultivation. However, linoleic and oleinic acids predominated in all the lipids except the lipids from submerged cultures growing in the form of unusually large clots. Such lipids contained up to 60 per cent of palmitic acid.

Chromatography, Gas↗

[Lipid characteristics of actinomycetes. I. The content and composition of lipid fractions].

The original experimental results and review of the literary data on the composition of total extractable Lipids in Streptomyces genus strains at the different growth stages grown on various composition media are given. The results of the investigation on lipids (including those of the membranes) which have not been earlier found in Streptomycetes are discussed. Special attention is given to changes of the membrane lipid component in connection with the growth phases and cultural conditions, particularly to the different rate of the membrane nitrogen-containing lipids interchange depending on the phosphate content in the medium.

Actinomycetales↗

[Effect of exogenous sterols on the growth and fatty acid composition of the oomycete Pythium debaryanum].

Exogenous ergosterol and cholesterol were found to affect the growth and lipogenesis of the oomycete fungus Pythium debaryanum, which is unable to synthesize de novo steroid compounds. These sterols stimulated the growth of the fungus during its submerged cultivation in glucose-peptone medium. This was accompanied by the shortening of the lag phase, the lengthening of the period of active growth, and by a 3.7- or 4.3-fold increase in the maximum biomass in response to the addition of ergosterol or cholesterol, respectively. In the presence of ergosterol, the cellular content of polyenoic fatty acids increased, and the relative content of eicosapolyenoic fatty acids reached 31.4% of the total amount of fatty acids in cells. Conversely, cholesterol decreased the cellular content of polyenoic acids, and the relative content of eicosapolyenoic acids fell to 19.6% of the total amount of fatty acids. It may be inferred that exogenous sterols enhance the yield of pharmacologically active polyenoic acids because of the growth stimulation.

Fatty Acids↗

[Effect of vitamin E and its functional analogs with different molecular structures on growth and lipids content of Pythium debaryanum].

The effect of exogenously added vitamin E and its synthetic analogues (the hydrophilic form of vitamin E and chromans C13 and C1) on the growth, lipogenic activity, and the fatty acid composition of the eicosapolyenoic acid-synthesizing oomycete Pythium debaryanum was studied. The effect was found to depend on the molecular structure of particular compounds. For instance, vitamin E and chroman C13 stimulated fungal growth, whereas chroman C1 inhibited it. The hydrophilic form of vitamin E enhanced the lipogenic activity of the oomycete. The studied compounds, which possess antioxidant activity, did not exert any noticeable effect on the level and the degree of the unsaturation of fungal lipids.

Lipid Metabolism↗

[Lipoamino acids in the composition of actinomycete polar lipids].

The capacity for substitution of phospholipids, in particular phosphatidyl ethanolamine, by a phosphorus-lacking lipoamino acid was studied in different groups of actinomycetes. In the conditions of phosphorus deficiency, most cultures were found to be capable of synthesizing a phosphorus-lacking nitrogen-containing lipoamino acid. Its characteristics (Rf) in TLC are similar to those of ornithinolipid. This fact confirms, for the first time and for different groups of actinomycetes, the hypothesis concerning interchangeability of membranous lipids. In the case of Actinomyces olivaceus, phosphatidyl ethanolamine and ornithine containing a phosphorus-lacking lipid can be regarded, this being corroborated by comparative data about their quantitative content. The detection of the phosphorus-lacking nitrogen-containing lipid in the composition of the polar fraction in different actinomycetes in the conditions of phosphorus deficiency in the medium demonstrates the possibility of adaptive changes in the composition of membranous lipids in microorganisms depending on their habitat.

Chromatography, Thin Layer↗