[Microorganisms--degraders of polychlorinated biphenyls]. / Mikroorganzimy--destruktory polikhlorirovannykh bifenilov.

Four strains belonging to the genus Bacillus, capable of degrading polychlorinated biphenyls (PCB), were isolated by screening the collection strains of soil bacteria, degrading a organochlorine pesticide, hexachlorocyclohexane (HCCH). A method for production of tritium-labeled PCB was developed. Consumption and degradation of PCB by the soil bacterial strains selected were studied using tritium-labeled PCB and GLC. It was demonstrated that PCB are degradable both in culture media and under in model soil samples.

[Change in biochemical composition of amaranth leaves as a result of selection for increased level of amaranthine pigment]. / Izmenenie biokhimicheskogo sostava list'ev amaranta v rezul'tate selektsii na povyshennoe soderzhanie pigmenta amarantina.

The composition and content of secondary compounds produced by the shikimate pathway and the contents of protein and cellulose were determined in leaves of amaranth (Amaranthus tricolor L.) K-99 and the cultivar Valentina raised from it by family selection and enriched in the pigment amaranthine. It was found that intense biosynthesis of amaranthine, tyrosine, and phenylalanine resulted in a decrease in the contents of lignin, protein, and cellulose in leaves of Valentina by comparison with K-99 and in changed the morphological traits: color deepening and a decrease in leaf density. It is concluded that amaranth biosynthesis is related to nitrogen metabolism and amaranthine is an intermediate involved in conversion of nitrogen compounds in the cell.

[Forms of silicon in medicinal plants]. / Formy kremniia v lekarstvennykh rasteniiakh.

The contents of three forms of silicon (organic, soluble mineral, and polymeric) were determined in leaves of 21 medicinal plants. At a total content of silicon 0.74 to 3.59% the organic, soluble mineral, and polymeric forms accounted for 0.51-1.91%, 0.05-0.51%, and 0.1-1.21%, respectively. An analysis of silicon in the condensed polyphenol fraction was performed for the first time revealing the presence of a covalently bound form in the amounts of 0.1 to 0.2% of the total silicon content in the leaves. These results are of interest for food or medical applications of the plants studied.

[Phenolic compounds in medicinal plants]. / Fenol'nye soedineniia v lekarstvennykh rasteniiakh.

Compositions of phenolic substances were studied in leaves of 21 species of medicinal plants. Flavonoid levels varied from 1.94 to 5.42%, whereas total amounts of monomeric polyphenols and hydroxybenzoic acids were estimated as 0.27 to 0.57%, and hydroxycinnamic acids and their esters with quinic acid, 0.09 to 0.18%. Condensed and polymerized polyphenols were detected in amounts of 0.41 to 1.20%. Qualitative compositions of flavonoids in leaves of seven plants studied were presented. The developed analytical procedures may be useful for plant polyphenol studies and as the basis of hemotaxonomy.

[Selenium and its role in nutrition]. / Selen i ego rol' v pitanii.

The review presents data available in the literature on the spread of selenium deficiency. Epidemiological surveys show that there is a potential risk for selenium deficiency in pregnant females and in 7-10-year-old children. The negative impact of radiation on serum selenium levels was evidenced by a survey of Chernobyl Atomic Power Station workers. Higher selenium levels in the hairs of the pubis, beard, celiac plexus, and axillary spaces than those in the hair of the head (by 1.41, 1.34, 1.36, and 1.14 times, respectively) confirm that there is a relationship between selenium and sexual hormones in the body. Dietary fiber concentrates that are derived from plant materials and contain a complex of structural carbohydrates and lignin may be used in combination with selenium compounds in human diets to prevent selenium deficiency.

[Oxyanthraquinones and flavonoids from garland chrysanthenum]. / Oksiantrakhinony i flavonoidy khrizantemy s''edobnoi (oboshchnoi).

The stems of the vegetable plant garland chrysanthemum (Chrysanthemum coronarium L.) were shown to contain emodin (in its aglycon and glycoside forms) and chrysophanol. Chrysophanol and chrysazin were isolated from the roots of the plant. Because the pigments identified are derivatives of 1,8-dihydroxyanthroquinone, garland chrysanthemum may be a medicinal plant and have utility as a component of laxative species. The leaves of C. coronarium were shown to be rich in quercetin and its glycosides, rutin and isoquercetin. Taken together, this observation and the known high content of ascorbic acid and carotenoids in the plant suggest that C. coronarium may be useful in preventing cardiac and vascular diseases.

[Two molecular forms of pea ferredoxin in the electron transport chain of chloroplasts]. / Osobennosti funktsionirovaniia dvukh molekuliarnykh form ferredoksina gorokha v tsepi élektronnogo transporta khloroplastov.

The effects of two molecular forms of water-soluble ferredoxin (Fd I and Fd II) on the kinetics of electron transport in bean chloroplasts (class B) were studied. The light-induced redox transitions of the photosystem I reaction center P700 were measured by the intensity of the EPR signal I produced by P700+. Both forms of ferredoxin, Fd I and Fd II, when added to the chloroplasts in catalytic amounts, stimulate the light-induced electron transfer from P700 to NADP+. Nevertheless, Fd I is a better mediator of the back reactions from NADPH to P700+. This electron transfer pathway is sensitive to the cyclic electron transport inhibitor, antimycin A, and to DCMU inhibitor of electron transport between photosystem II and plastoquinone. It may be concluded that the two molecular forms of ferredoxin, Fd I and Fd II, differ in their ability to catalyze cyclic electron transport in photosystem I. The role of Fd I and Fd II in regulation of electron transport at the acceptor site of photosystem I is discussed.

[Participation of its reaction center in the electrochemical reduction of ferredoxin]. / Ob uchastii v élektrokhimicheskom vosstanovlenii ferredoksina ego reaktsionnogo tsentra.

In the experiments with reaction center modification of ferredoxin its participation in reduction has been shown. Polarographic characteristics of ferredoxin and apoferredoxin have been compared. While removing iron and labile sulphur from ferredoxin reaction center the reduction wave of Fe-S bonds with E 1/2 = -0.33 V (N. H. E.) transforms into the reduction wave of S-S bonds with E 1/2 = -0,39 V at pH = 7.

[Effects of specific reagents and urea on the reactivity of non-heme iron and thiol groups of pea and corn ferredoxins]. / Reaktsionnaia sposobnost' negemovogo zheleza i tiolovykh grupp ferredoksinov gorokha i kukuruzy pri deistvii spetsificheskikh reagentov i mocheviny.

The reactivities of the SH-groups of pea and corn ferredoxins were found to be different. One or two SH-groups in the molecule of pea ferredoxin and one SH-group in the molecule of corn ferredoxin are readily available for the thyol group specific reagents. Four SH-groups of both ferredoxins are completely masked, i. e. available for the thyol reagents only after protein denaturation in the presence of urea. The rates of SH-group interaction with the sulfhydryl reagents in corn ferredoxin are lower than those in pea ferredoxin. The non-haem iron of pea ferredoxin interacts with the complex formers far more rapidly as compared to corn ferredoxin. The ferredoxins tested differ in the amount of iron atoms. The latter require the presence of oxygen for their complete interaction with the complex formers.

Characterization of plastocyanin from corn (Zea mays L.) and pea (Pisum sativum L.) leaves.

A comparison of plastocyanin isolated from pea and corn leaves was made according to a number of indices. No appreciable differences were detected between the proteins in molecular weight or sedimentation constants. In addition, it was shown that plastocyanin of corn, in comparison with the pea protein, possesses greater thermal stability, is more resistant to the action of high and low H+ ion concentrations, as well as to the action of concentrated solutions of urea and guanidine nitrate. The detected differences indicate peculiarities in the molecular organization of plastocyanins from various groups of plants. It is suggested that the differences noted in the structure of plastocyanins can ensure effective functioning of proteins under nonuniform conditions of the external environment.

[Ferredoxin reduction by polarographic methods]. / O vosstanovlenii ferredoksina poliarograficheskimi metodami

The reduction of iron-sulphur protein of the higher plant ferrodoxin has been studied by polarographical methods. Ferredoxin initiates a reversible wave with E1/2=--0,61 v (N. C. E.) at pH 7. Protein absorption greatly influences the electrochemical reduction. The protons have been shown to take part in the electrode reaction. The potentiometrically obtained data about the difference between E1/2 and E0=--0.70 v and its causative factors are discussed. As a result of the experiments with modification of ferredoxin active centre it has been concluded that the active centre participates in the polarographical reduction.