bluuebunny/crossref_metadata_2025 huggingface dataset:
Concentrations of Anthraquinone Glycosides of Rumex crispus during Different Vegetation Stages
Authors: Demirezer L. Ömür
Published: August 2018

The anthraquinone glycoside contents of various parts of Rumex crispus L. (Polygonaceae) in different vegetation stages were investigated by thin layer chromatographic and spectro-photometric methods. The data showed that the percentage of anthraquinone glycoside in all parts of plant increased at each stage. Anthraquinone glycoside content was increased in leaf, stem, fruit and root from 0.05 to 0.40%, from 0.03 to 0.46%, from 0.08 to 0.34%, and from 0.35 to 0.91% respectively. From the roots of R. crispus, emodin-8-glucoside, RGA (isolated in our laboratory, its structure was not elucidated), traceable amount of glucofrangulin B and an unknown glycoside (Rf = 0.28 in ethyl acetate:m ethanol:water/100:20:10) was detected in which the concentration was increased from May to August. The other parts of plant contained only emodin-8-glucoside
Subcellular Localization of Quinate: Oxidoreductase from Phaseolus mungo L. Sprouts
Authors: Kang Xiangbo , Neuhaus H. Ekkehard , Scheibe Renate
Published: August 2018

Quinate:oxidoreductase (QORase, EC 1.1.1.24) was isolated and purified from etiolated mung bean (Phaseolus mungo L.) sprouts and a monospecific antiserum was raised in rabbit to the homogeneous protein. Highly intact etioplasts were isolated from the same plant material. The stroma of the purified etioplasts was enzymatically characterized. Contamination by cytosol, mitochondria and vacuole was estimated from activities of marker en­zymes. QORase activity was localized in the stroma (about 91% for both NAD+ and NADP+ as a cofactor). Western blotting and immunoprinting of the stroma proteins revealed a single band that migrated identically with the purified QORase. The results suggest that the QOR-ase is localized predominantly, if not exclusively, in the etioplast stroma. The physiological role of the enzyme is discussed
Calmodulin Regulates Nucleotide Hydrolysis Activity of Tissue Transglutaminase
Authors: Takeuchi Yutaka , Birckbichler Paul J. , Patterson Manford K. , Kyung  , Lee N. , Carter Henry A.
Published: August 2018

The interaction of calmodulin with purified guinea pig liver transglutaminase was studied. The nucleotide (ATP and GTP) hydrolysis activity of this tissue transglutaminase was tran­siently increased and then gradually decreased depending on calmodulin concentration. The peak activation was obtained in the presence of a stoichiometric amount of calmodulin. The effect of calmodulin on the classical transglutaminase activity was minimal. Fluorescence spectroscopy demonstrated that the enzyme produced a significant blue shift in the emission peak of dansylated calmodulin. Interestingly, Ca2+ was not required for the interaction between the two proteins. The results described here give an additional regulatory role to calmodulin
Structure-Antifilarial Activity Relationship of 5/6/7/8-Mono-or Disubstituted 1H/1-Phenyl-9H-pyrido[3,4-b]indoles -A New Class of Potential Filaricides
Authors: Agarwal Alka , Agarwal Shiv K. , Singh Som Nath , Fatma Nigar , Chatterjee R. K.
Published: August 2018

Antifilarial activity of 5/6/7/8-mono-or disubstituted 1 H /1-phenyl-9H -pyrido[3,4-b]indoles (I) has been described. The 1,6-and 8 -substituted 9H-pyrido[3,4-b]indoles (I) elicited inter­esting filaricidal activity against Litomosoides carinii and Acanthocheilonema viteae in rodent hosts
Ionic Permeabilities of Different Isolated Fruit Cuticles Calculated by Conductivity and Membrane Potential Measurements
Authors: Benavente J. , Muñoz A. , Heredia A.
Published: August 2018

Membrane potential and electrical resistance for two isolated fruit cuticular membranes (tomato and pepper cuticles) were measured for different NaCl solutions (10-3 ᴍ < C < 5 × 10-2 ᴍ). From these experimental results some membrane characteristic parameters were obtained such as cation transport number, t+, which represents the fraction of the electric current transported by the cation, l+ , with respect to the total current, lT (t+ = l+/lT) , and ionic permeabilities, P+ and P-, for both membranes. Concentration dependence of these parameters was also considered. A comparative study between both types of fruit cuticles is also made. It was found that cation transport number, ionic permeabilities and electrical resistances are quite similar for both membranes.
Phenolic Compounds in Needles of Norway Spruce Trees in Relation to Novel Forest Decline. II. Studies on Trees from Two Sites in Middle Western Germany
Authors: Richter Christine M. , Wild Aloysius
Published: August 2018

The content of several phenolic compounds in needles of 20- to 30-year-old Norway spruce trees (Picea abies) was measured using HPLC. The results of two forestry sites in middle western Germany are reported in this paper. They are part of a research programme on novel forest decline which was carried out in various regions of Germany. Distinct amounts of picein, catechin, piceatannol glucoside, and other phenolic compounds were detected in the studied spruce needles. Additionally, their contents changed in relation to damage. Some compounds, especially catechin, showed increased levels in the needles of the damaged trees compared to the undamaged ones. Here, the values for the undamaged trees of the different sites were similar. Concerning the changes in picein contents, however, there was a great difference between the sites. p-Hydroxyacetophenone was detected in very low amounts only and did not correlate with damage.

These results are compared with earlier findings from another site that shows severe damage. The role of phenolic compounds as indicators of tree damage is discussed.
The Role of Phytoalexins in the Seedling Resistance to Leptosphaeria maculans in Some Crucifers
Authors: Storck Michael , Sacristán Maria D.
Published: August 2018

Brassica juncea, Brassica carinata and Sinapis arvensis resistant lines to Leptosphaeria maculans and four Brassica napus cuitivars susceptible to this pathogen in seedling stage were analyzed in relation to the accumulation of phytoalexins after inoculation with L. maculans. Cotyledon inoculations with spore suspensions of an aggressive and a non-aggressive isolate of L. maculans were performed on seedlings of these lines. The quantity of accumulated phytoalexins in the cotyledons was determined at different time intervals after inoculation. The content and composition of phytoalexins differed considerably among the tested species and according to the fungal isolate used. In the tested Brassica species seedling resistance against L. maculans could not be related to phytoalexin accumulation. However, in Sinapis arvensis phytoalexins might contribute to the resistance reaction to this pathogen.
Enzymatic Biosynthesis of Vomilenine, a Key Intermediate of the Ajmaline Pathway, Catalyzed by a Novel Cytochrome P 450-Dependent Enzyme from Plant Cell Cultures of Rauwolfia serpentina
Authors: Falkenhagen Heike , Stöckigt Joachim
Published: August 2018

Microsomal preparations from Rauwolfia serpentina Benth. cell suspension cultures cata­lyze a key step in the biosynthesis of ajmaline -the enzymatic hydroxylation of the indole alkaloid vinorine at the allylic C-21 resulting in vomilenine. Vomilenine is an important branch-point intermediate, leading not only to ajmaline but also to several side reactions of the biosynthetic pathway to ajmaline. The investigation of the taxonomical distribution of the enzyme indicated that vinorine hydroxylase is exclusively present in ajmaline-producing plant cells. The novel enzyme is strictly dependent on NADPH2 and O2 and can be inhibited by typical cytochrome P450 inhibitors such as cytochrome c, ketoconazole and carbon mon­oxide (the effect of CO is reversible with light of 450 nm). This suggests that vinorine hy­droxylase is a cytochrome P450-dependent monooxygenase. A pH optimum of 8.3 and a temperature optimum of 40 °C were found. The Km value was 3 μᴍ for NADPH2 and 26 μᴍ for vinorine. The optimum enzyme activity could be determined at day 4 after inoculation of the cell cultures in AP I medium. Vinorine hydroxylase could be stored with 20% sucrose at -28 °C without significant loss of activity.
Anthranilate Synthase and Chorismate Mutase Activities in Stem Rust-Inoculated and Elicitor-Treated Resistant, Moderately Resistant, and Susceptible Near-Isogenic Wheat Lines
Authors: Bücker Claudia , Witte Barbara , Windmüller Ursula , Grambow Hans J.
Published: August 2018

Anthranilate synthase and chorismate mutase activities which control the flow of substrate from chorismate into the tryptophan pathway and into the phenylalanine/tyrosine pathway, respectively, were examined in three near isogenic wheat lines of Triticum aestivum L. (cv. Prelude Sr 5, highly resistant to stem rust infection; cv. Prelude Sr 24, moderately resistant; cv. Prelude srx, susceptible). The activities of both enzymes were found to increase in re­sponse to inoculation with the stem rust fungus Puccinia graminis f. sp. tritici or treatment with Pgt elicitor. Thus, both the tryptophan branch and the phenylalanine branch appear to contribute to the resistance response in wheat leaves. Only the cytosolic but not the plastidic fraction of the enzyme activities appears to be affected by fungal infection or elicitor treat­ment. Some differences with respect to degree and time dependency of enzyme activation were noticed between the three wheat lines following inoculation but not after treatment with the Pgt elicitor.
Blue Light-Enhanced Photosynthetic Oxygen Evolution from Liposome-Bound Photosystem II Particles; Possible Role of the Xanthophyll Cycle in the Regulation of Cyclic Electron Flow Around Photosystem II?
Authors: Gruszecki W. I. , Strzałka K. , Radunz A. , Kruk J. , Schmid G. H.
Published: August 2018

Light-driven electron transport in liposome-bound photosystem II (PS-II) particles be­tween water and ferricyanide was monitored by bare platinum electrode oxymetry. The modi­fication of the experimental system with the exogenous quinones α-tocopherol quinone ( α-TQ) or plastoquinone (PQ) resulted in a pronounced effect on photosynthetic oxygen evolution. The presence of α-tocopherolquinone ( α-TQ) in PS-II samples decreased the rate of red light-induced oxygen evolution but increased the rate of green light-induced oxygen evolution. Blue light applied to the assay system in which oxygen evolution was saturated by red light resulted in a further increase of the oxygen signal. These findings are interpreted in terms of a cyclic electron transport around PS-II, regulated by an excitation state of β-carotene in the reaction centre of PS-II. A mechanism is postulated according to which energetic coupling of β-carotene in the reaction centre of PS-II and that of other antenna carotenoid pigments is regulated by the portion of the xanthophyll violaxanthin, which is under control of the xanthophyll cycle.
Characteristics of Thermoluminescence Bands of Euglena Cells Belonging to 2 Lines Presenting Different Degrees of Diuron-Resistance
Authors: Farineau Jack , Laval-Martin Danielle
Published: August 2018

We have analysed the thermoluminescence (TL) properties of two lines of Euglena exhibiting two degrees of resistance to diuron, by a factor of 100 (ZR 25) and 1000 (ZR 250) respectively, as compared to wild type line (Z). In addition, the two ZR lines developped an identical resistance to atrazine since the I50 for this herbicide in each line was 75 times larger than in wild type. Special TL characteristics were evidenced in the two lines. Bands after 2 flashes (or more) showed a shift of the peak maximum towards low temperature, the shift being the largest in the most DCMU-resistant cells. Similar results were obtained with isolated thylakoids, except that the TL bands appeared at a temperature higher than in corresponding cells. Oscillations in the amplitude of the bands in a flash sequence were largely damped in cells (and thylakoids), particularly in the most DCMU-resistant lines. The results are interpreted as indicating accumulation of Qᴀ −Qʙ after flashes due to a decrease of the equilibrium constant for the reaction Qᴀ − Qʙ ⇄ QᴀQʙ− accompanying the DCMU resistance.
Plant Constituents Interfering with Human Sex Hormone-Binding Globulin. Evaluation of a Test Method and Its Application to Urtica dioica Root Extracts
Authors: Ganßer Dietmar , Spiteller Gerhard
Published: August 2018

A test system is described, which allows the search for compounds interfering with human sex hormone-binding globulin (SHBG) even in complex plant extracts. The method has been evaluated and applied to Urtica dioica root extracts. The lignan secoisolariciresinol (5) as well as a mixture of isomeric (11 E)-9,10,13-trihydroxy-11-octadecenoic and (10 E)-9 ,12,13-trihydroxy-10-octadecenoic acids (3 and 4, resp.) were demonstrated to reduce binding activity of human SHBG. Methylation of the mixture of 3 and 4 increased its activity about 10-fold.
Charging of Both, Plastidal tRNAgln and tRNAglu with Glutamate and Subsequent Amidation of the Misacylated tRNAgln by a Glutamyl-tRNA Amidotransferase in the Unicellular Green Alga Scenedesmus obliquus, Mutant C-2A'
Authors: Vothknecht U. C , Dörnemann D
Published: August 2018

, 1995 C5-Pathway, Glutamyl-tRNAglu-Synthetase (E.C.6.1.1.17), Misacylation of tR N A glu, Amidotransferase, Scenedesmus obliquus In a previous paper we described the purification of a glutamyl-tRNA synthetase from the unicellular green alga Scenedesmus obliquus, m utant C-2A'. We now dem onstrate that, firstly, this enzyme is capable of mischarging plastidal tR N A gln from barley with glutamate, as well as it regularly charges the plastidal tR N A glu from Scenedesmus. Secondly, we show that the mischarged glutamyl-tRNAgln is subsequently am idated by a glutamyl-tRNA am idotransfer­ ase to form the glutaminyl-tRNAglri required for plastidal protein biosynthesis. This phenom ­ enon could already be dem onstrated for higher plant chloroplasts, mitochondria, cyanobact­ eria and gram-positive bacteria, as far as investigated. As recently shown the applied glutamyl-tRNA synthetase from Scenedesmus is a plastidal enzyme. In this paper we prove by treatm ent with m onobromobim ane and cyanogen bromide that the "regular" substrate of the enzyme, tR N A glu from Scenedesmus, is a plastidal tRNA with the plastid-specific sulfur modification in the anticodon. In the case of cyanogen bromide treatm ent, a total inactivation of the tRNA was achieved, revealing the presence of a sulfur modification in the plastid-tRNA glu anticodon.
Role of Mucus Secretion and Sulfhydryl Groups in Gastroprotection Mediated by a Flavonoid Fraction of Bidens aurea
Authors: La Casa C , Calero M. J. Martín , Alarcón de la Lastra C , Motilva V , Ayuso M. J , Cordero C. Martín , Vergara A. López
Published: August 2018

Abstract The aerial parts of Bidens aurea (Aiton) Sherff have been used in folk medicine as an antiulcer agent. The efficacy of an ether extract to prevent gastric mucosal damage produced by several necrotic agents was studied in rats. The best efficiency was against lesions induced by 30% NaCl with a significant decrease of damage at all doses tested (250, 125 and 62.5 mg kg-1). In contrast, only the highest dose (250 mg kg-1) was effective on gastric erosions induced by 0.6 ɴ HCl. This effect could not be related with the mucus gel production only since the groups treated with of absolute ethanol or 30% NaCl before and then received 250 mg kg-1 of the ether extract increased significantly the amount of gastric mucus and its glycoprotein content. However, the ether extract of Bidens aurea enhanced the production of mucosal non-protein SH groups at all doses assayed after treatment with absolute ethanol and 0.6 ɴ HCl. With NaCl-induced gastric injury, also the highest dose (250 mg kg-1) produced an increase of this parameter. The results suggest that a slight augmentation of the mucus gel concentration and the increase of non-protein sulfhydryl compounds, could con­ tribute to the functional protection mechanism mediated by a flavonoid fraction of B.aurea in these experimental models.
Selektion und Mutation aus informationstheoretischer Sicht - Grenzen der Erhaltbarkeit von genetischer Information / Selection and Mutation from the Informationtheoretical Point of View - Limits of the Preservation of Genetical Information
Authors: Tiefenbrunner Wolfgang
Published: August 2018

There is no doubt that evolution can only operate in accordance with the laws of thermodynamics. To transform this simple perception into a statement that can be quantified it is necessary to examine how the entropy (or the in formation content) changes by means of the two main factors of evolution: selection and mutation . In the present paper this aim was reached by using the methods of information theory.

That evolution becomes possible the change of information by mutation and selection must not be negativ in the long run. Consequently an upper limit for the information content of the genom must be assumed. If the evolution as a self-optimizing process gains this upper limit it reaches a dynamic equilibrium at which the increase of entropy by mutation balances the decrease of entropy by selection. In particular it was examined under which circumstances of dynamic equilibrium mastergenotypes (genotypes that can preserve their specific sequence over a long time) can exist.
Mass Spectrometric Detection and Analysis of Nitrogen Fixation in Oscillatoria chalybea
Authors: Bader Klaus P. , Röben Anja
Published: August 2018

By means of mass spectroscopic measurements in an artifical gas atmosphere containing the stable nitrogen isotope 15N2 we were able to demonstrate nitrogen fixation capacity in the filamentous cyanobacterium Oscillatoria chalybea. Our technique proved to be wellsuited also for investigations on the light-induced nitrogen fixation in the purple bacteria Rhodobacter sphaeroides and Rhodobacter capsulatus. Oscillatoria chalybea grown without combined nitrogen showed a substantial 15N2-uptake which could clearly be correlated with nitrogen fixation. Nitrate grown cultures did not show this nitrogen uptake or only to a minimal extent. Addition of ammonium chloride resulted in a rapid deactivation of the nitrogenase system. Similar observations have been made with other so-called switch-off effectors like phenazine methosulfate. The structural integrity of the filaments appeared to be a prerequisite for nitrogen fixation also in this organism, as even mild mechanical homogenization strongly inhibited the N2-uptake signals. Illumination of the assays under conditions where the photooxidition of water is not operational (Bader, K. P. (1994), Biochim. Biophys. Acta 1188, 213 -219) did not affect the nitrogen fixation in Oscillatoria chalybea. Illumination of cultures with concomitant release of oxygen from the water splitting reaction resulted in strong inhibition of 15N2-uptake.
Glutathione Peroxidase-Like Activity of Simple Selenium Compounds. Peroxides and the Heterocyclic N-Oxide Resazurin Acting as O-Atom Donors
Authors: Prtitz Walter A.
Published: August 2018

Selenite and selenocystamine [(CyaSe)2] efficiently activate the decomposition of H2O2 y GSH and by other thiols, as demonstrated using a leuco crystal violet POD-based H2O2 assay which is applicable (unlike other assays) also in presence of thiols. The GPx-like activities were estimated to be 3.6 and 2.7 μmol H2O2/min per μmol SeO3
2- and (CyaSe)2, respectively. Both selenium compounds also activate reduction of the heterocyclic N-oxide resazurin (RN→O) to resorufin (RN) by GSH; H2O2 competes with reduction of this dye. GSSeH and CyaSeH, formed by interaction of GSH with SeO3
2- and (CyaSe)2, respectively, are likely to be the active reductants. CyaSeH, generated γ-radiolytically from (CyaSe)2, exhibits an absorption peak at 243 nm and is removed by H2O2 with a rate constant of 9.7x102 ᴍ-1 s-1, and slightly slower by hydroperoxides. We have no evidence for one-electron interactions between GSSeH or CyaSeH and H2O2, with formation of free radical intermediates, as previously proposed in the case of selenium-activated reduction of cytochrome c by GSH (Levander et al., Biochemistry 23, 4591-4595 (1973)). Our results can be explained by O-atom transfer from the substrate to the active selenol group. RSeH + H2O2 (RN→O)→RSeOH + H2O (RN), and recycling of RSeOH to RSeH (+ H2O) by GSH, analogous to the selenenic acid pathway of GPx. The substrate specificity appears to be different, however, in that GPx is unable to catalyse RN→O reduction, and GSSeH hardly catalyses the decomposition of cumene- or t-butyl-hydroperoxide; CyaSeH, on the other hand, is active also with the hydroperoxides. RN→O is reduced to RN also by certain oxidizing free radicals, e.g. by the thiyl CyaS·; O -atom transfer may in this case lead to the generation of reactive oxyl radicals.
Interaction of the Antiarrhythmic Drug Procainamide with Phospholipid Bilayers
Authors: Suwalsky M. , Villena F. , Bagnara M. , Sotomayorc C. P.
Published: August 2018

Several hypotheses link the molecular mechanism of action of the antiarrhythmic drugs (AAD) that belong to class I to non-specific interactions with phospholipids sited in the neighborhood of sodium channels in the membrane of the myocardium. Procainamide (PROC ), one of the least lipophilic drugs of this group, was induced to interact with bilayers of dimyristoylphosphatidylcholine (DMPC) and dimirystoylphosphatidylethanolamine (DMPE), liposomes of DMPC and human erythrocytes. The perturbing effects of PROC upon these systems were respectively determined by X-ray diffraction, fluorescence spectroscopy and scanning electron microscopy. It was found that PROC exerted very little effect upon DMPC and DMPE even at such a high concentration as 10 mᴍ . However, at therapeutical plasma concentrations, PROC induced shape changes in vitro to red cells.
Molecular Phylogeny of South American Screech Owls of the Otus atricapillus Complex (Aves: Strigidae) Inferred from Nucleotide Sequences of the Mitochondrial Cytochrome b Gene
Authors: Heidrich Petra , König Claus , Wink Michael
Published: August 2018

The cytochrome b gene of 6 South American screech owls of the genus Otus (O. choliba, O. atricapillus, O. usta, O. sanctaecatarinae, O. guatemalae, and O. hoyi) and two Old World species (Otus scops and Otus leucotis) was amplified by polymerase chain reaction (PCR) and partially sequenced (300 nucleotides). Otus atricapillus, O. guatemalae, O. hoyi and O. sanctaecatarinae which are morphologically very similar, have been treated as belonging to a single species, A. atricapillus (Sibley and Monroe, 1990). Nucleotide sequences differ substantially between these taxa (6.3 to 8.8% nucleotide substitutions) indicating that they represent well established and distinct species which had been implicated already from ecological and bioacoustical analyses (König, 1991, 1994). The importance of vocal and ecological characters for the taxonomy of nocturnal birds is thus confirmed by our molecular analysis. Phylogenetic relationships were reconstructed between Old and New World owls using character state (“maximum parsimony”; PAUP 3.1.1) and distance matrix methods (neighbour- joining; MEGA).
Adipokinetic Neuropeptides and Flight Metabolism in Three Moth Species of the Families Sphingidae, Saturniidae and Bombycidae
Authors: Liebrich Walter , Gäde Gerd
Published: August 2018

Methanolic extracts from corpora cardiaca of three moth species, Hippoteon eson (Sphingidae), Imbrasia cytherea (Saturniidae) and Bombyx mori (Bombycidae) show adipokinetic activity in conspecific bioassays. Haemolymph carbohydrates in these moths are not affected. These extracts are also active in heterologous bioassays: haemolymph lipids are increased in Locusta migratoria, whereas a small effect on haemolymph carbohydrates was observed in Periplaneta americana. Therefore, locusts can be used to monitor adipokinetic activity in corpora cardiaca from moth extracts during isolation. The three moth species possess an adipokinetic peptide with the same retention time on reversed phase high performance liquid chromatography (RP -HPLC) as a peptide isolated previously from Manduca sexta, which was code-named Mas-AKH. H. eson contains a second active peak with a similar retention time on RP-HPLC as the hypertrehalosaemic peptide isolated previously from Helicoverpa zea , code-named Hez-HrTH. Both synthetic peptides, Mas-AKH and Hez-HrTH, produce an adipokinetic effect in the three experimental moth species. In H. eson, the haemolymph concentration of Mas-AKH or Hez-HrTH needed to elicit a maximum hyperlipaemic response is about 20 to 30 nᴍ.

Flight behaviour in the three moth species is quite different: H. eson is a good hovering flyer, I. cytherea is a comparatively bad flyer and B. mori males show only degenerate flight movements during their mating dance. Haemolymph lipid levels in H. eson decrease drastically during 15 min of flight and return to pre-flight levels in a subsequent rest period. The amount of lipids metabolized during flight is 10.9 mg/gxhr. Haemolymph carbohydrate levels drop during flight, but remain low during the 45 min of recovery. Haemolymph lipids in “dancing” males of B. mori remain constant. In individuals, however, which have low initial lipid levels in the blood, lipid concentrations increase significantly in a subsequent 15 min rest period after “dancing”. Metabolic changes during flight in I. cytherea were not investigated due to this species’ poor flight performance.
Notes: A Plant Growth Regulator from Vernonia auriculifera (Asteraceae)
Authors: Keriko Joseph Mungai , Nakajima Shuhei , Baba Naomichi , Isozaki Yumika , Ikeda Kyoko , Iwasa Junkichi , Karanja Paul Nyota
Published: August 2018

From the methanolic extract of fresh leaves of the Kenyan Vemonia auriculifera Hiern., a lettuce seeds growth regulator was isolated and identified as 8-desacylvernodalol (1) by spectroscopic analysis.
Molecular Interactions of Quinidine with Phospholipid Bilayers
Authors: Suwalsky M. , Villena F. , Bagnara M. , Sotomayor C. P.
Published: August 2018

Quinidine (QUIN) is one of the most important and efficient antiarrhythmic drugs (AAD). It belongs to class I. which are the drugs that exert their action at the level of the sodium channels in the membrane of the myocard. Several hypotheses support the idea that the molecular mechanism of action of the AAD is via nonspecific interactions with phospholipids sited in the neighborhood of the channels. In order to probe the validity of these hypotheses, QUIN was made to interact with the phospholipids dimyristoylphosphadidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE). These interactions were performed in a hydrophobic and a hydrophilic medium under a wide range of molar ratios. The resulting products were analyzed by X-ray diffraction. QUIN solutions were also made to interact with DMPC liposomes, which were studied by fluorescent spectroscopy. Finally, human erythrocytes which were incubated with QUIN solutions were observed by scanning electron microscopy. The results of these experiments proved that QUIN indeed interacted with phos­pholipid bilayers.
Membrane Association of the Rieske Iron-Sulfur Protein
Authors: Szczepaniak Andrzej , Frank Karin , Rybka Jacek
Published: August 2018

The mode of membrane attachment of the Rieske iron -sulfur proteins from cytochrome b6ƒ complex of pea thylakoids and from cytochrome bc1 complex of yeast mitochondria has been studied using biochemical approaches.

The relative sensitivity of the Rieske protein to trypsin in the thylakoid membrane shows that all trypsin sites of the Rieske protein are on the lumen side of the thylakoid membrane. In contrast to cytochrome / the chloroplast Rieske protein was extracted from thylakoids using chaotropic agents (NaSCN, urea), an alkaline pH and relatively low concentrations of Trinon X-100. The cytochrome bc1 complex Rieske protein from mitochondrial membranes of yeast was also released by NaSCN and alkaline treatment.

The results presented here led us to the conclusion, that the mitochondrial and chloroplast Rieske proteins are extrinsic and that their association with the rest of the complex involves hydrophobic interactions.
Antioxidant Profile of Mono-and Dihydroxylated Flavone Derivatives in Free Radical Generating Systems
Authors: Montesinos María Carmen , Ubeda Amalia , Terencio María Carmen , Payá Miguel , Alcaraz María José
Published: August 2018

A number of free radical generating systems were used to investigate the antioxidant properties and structure-activity relationships of a series of monohydroxylated and dihydrox­ylated flavones. Ortho-dihydroxylated flavones showed the highest inhibitory activity on en­ zymic and non-enzymic microsomal lipid peroxidation as well as on peroxyl radical scaveng­ing. Most flavones were weak scavengers of hydroxyl radical, while ortho-dihydroxylated flavones interacted with superoxide anion generated by an enzymic system or by human neutrophils. This series of compounds did not exert cytotoxic effects on these cells. Scaveng­ing of superoxide and peroxyl radicals may determ ine the antioxidant properties of these active flavones.
Pharmacokinetic Interaction between 4′-Epidoxorubicin and the Multidrug Resistance Reverting Agent Quinine
Authors: Czejka Martin , Bandak Suzan , Simon Doris , Schiiller Johann , Weiss Claudia , Schernhammer Eva
Published: August 2018

The serum and red blood cell (RBCs) disposition of epirubicin (EPR) after intravenous bolus injection without and with coadministered quinine (QUI) was investigated in patients undergoing a cyclic chemotherapy with EPR. QUI possesses a statistical significant influence on the EPR serum concentrations and, as a consequence, on the pharmacokinetic parameters for the initial distribution phase of EPR. Within the first 15 min after administration, EPR was distributed from the central compartiment distinctly faster in compare to the control, when QUI was preadministered (t1/2 = 6 min for the control group and t1/2 = 3 min with QUI; -46% , p < 0.05). Yet, in the beta-phase when drug-elimination predominates, no statistical significant influence of QUI in regard to EPR serum and RBC concentrations could be observed. Half-life of elimination was 9.5 h for the control group and 8.6 h for the QUI group (-10% ). The mean initial serum concentration (c0) was reduced significantly by QUI from 7359 ± 506 ng/ml to 4351 ± 1682 ng/ml (-42 % . p < 0.005). Furthermore. QUI caused a reduction of the serum bioavailability of EPR (expressed as AUC0-24-values) from 3404 ± 1008 ng/ml × h to 2359 ± 1073 ng/ml × h (-3 1 % , p < 0.05). Vd and Vdß were increased at about 90% and the mean total body clearance was accelerated from 45.3 to 148.7 ml/min, but due to the large standard deviations the calculated difference for these parameters was not statistically significant. In the observed time interval of 24 h, the red blood cell coefficient of distribution kRBC of EPR was lower if QUI was coadministered (kRBC = 1.25 ± 0.12 for the control group kRBC = 1.15 ± 0.13 under QUI; p < 0.04). The results point out that QUI induces an accelerated distribution of EPR from the blood into the tissue and that QUI additionally may have influence on the red-blood cell partitioning of EPR.
Distribution and Stereochemistry of Hydroxycinnamoylmalic Acids and of Free Malic Acids in Papaveraceae and Fumariaceae
Authors: Boegge Sabine C. , Nahrstedt Adolf , Linscheid Michael , Nigge Walter
Published: August 2018

The distribution of hydroxycinnamoylmalic acids (HCM acids) in 25 species and 2 subspecies of Papaveraceae and Fumariaceae representing 14 genera was investigated by HPLC and subsequent diode array detection (DAD). In case of similar chromatographic and UV-spectrometric behavior of HCM acids and other hydroxycinnamic acid derivatives liquid chromatography-thermospray/mass spectrometry (LC-TSP/MS) was used for positive identification. Ten of the species were found to contain caffeoyl-, p-coumaroyl-. and feruloylmalic acid whereas Chelidonium majus only showed the presence of caffeoylmalic acid. Sinapoylmalic acid could not be detected. The quantitative determ ination by HPLC at 330 nm yielded the highest content of caffeoylmalic acid for Fumciria officinalis and F. capreolata, and the lowest for Chelidonium majus. Isolated HCM acids showed positive optical rotation for members of the Papaveraceae and negative values for m em bers of the Fum ariaceae. This points to an esterification of hydroxycinnam ic acids with (-)-ʟ -malic acid for the Papaveraceae and with (+)-ᴅ-malic acid for the Fumariaceae. For plants containing HCM acids the contents of free l - and ᴅ-malic acid w ere determ ined enzym atically Yields of ʟ-malic acid were higher for Papaveraceae than for Fum ariaceae; ᴅ-malic acid was detectable only in traces for all investigated species. The Fum ariaceae showed a ca. 1:1 relationship between free ʟ-malate and esterified ᴅ-malate. This suggests an enzym atic racem ization of the original ʟ-malate and a subsequent esterification of the intermediate ᴅ-malate with hydroxycinnamic acids
Genes Leave Their Characteristic Marks on the Melting Profile of Plasmid DNAs
Authors: Zubrzycki Igor Z. , Klump Horst H.
Published: August 2018

High resolution melting profiles of four linearised plasmids (pUC9, pGV403, pHP2, and pBR322) were recorded by means of UV absorbance vs. teperature scaning. The set of transitions obtained for each plasmid are compared to each another and to the transitions obtained for their excised particular antibiotica resistance gene. It can be shown that each gene leaves a charactersitic mark on the melting profile of its parental plasmid
Cooperative Binding of the Organophosphate Paraoxon to the (Na+ + K+)-ATPase
Authors: Blasiak Janusz
Published: August 2018

Paraoxon. the main active metabolite of the organophosphorus insecticide parathion. exerted a dose-dependent inhibitory effect on the activity of pig kidney (Na+ + K+)-ATPase contained in microsomal fraction and purified from it. Substrate kinetics studies revealed the existence of two active sites with high and low affinity to ATP. The Dixon analysis of the mode of the inhibition indicated its noncompetitive character. The purified enzyme was more affected than enzyme contained in the microsomal fraction. The inhibition constant K, ranged from 73 to 246 μm depending on the type of preparation. The Hill coefficient (n) fulfilled the relationship 1<n<3. These properties of the interaction suggest the cooperative binding of paraoxon to the enzyme. An indirect mechanism of the interaction was proposed: paraoxon could inhibit the activity of the (N a+ + K+)-ATPase by excluding the enzyme protein from its normal lipid milieu
Bioactive Alkaloids from the Tropical Marine Sponge Axinella carteri
Authors: Supriyono A. , Schwarz B. , Wray V. , Witte L. , Müller W. E. G. , Soest R. van , Sumaryono W. , Proksch P.
Published: August 2018

Analysis of the tropical marine sponge Axinella carteri afforded six unusual alkaloids, including the new brominated guanidine derivative 3-bromo-hymenialdisine. The structure elucidation of the new alkaloid is described. The alkaloid patterns of sponges collected in Indonesia or in the Philippines were shown to be qualitatively identical suggesting de novo synthesis by the sponge or by endosymbiontic microorganisms rather than uptake by filterfeeding. All alkaloids were screened for insecticidal activity as well as for cytotoxicity. The guanidine alkaloids hymenialdisine and debromohymenialdisine exhibited insecticidal activity towards neonate larvae of the polyphagous pest insect Spodoptera littoralis (LD50s of 88 and 125 ppm, respectively), when incorporated into artificial diet and offered to the larvae in a chronic feeding bioassay. The remaining alkaloids, including the new compound, were inactive in this bioassay. Cytotoxicity was studied in vitro using L5178y mouse lymphoma cells. Debromohymenialdisine was again the most active compound (ED50 1.8 μg/ml) followed by hymenialdisine and 3-bromohymenialdisine, which were essentially equitoxic and exhibited ED50s of 3.9 μg/ml in both cases. The remaining alkaloids were inactive against this cell line
Photosynthetic Characteristics of Three Strains of Cyanobacteria Grown under Low-or High-C02 Conditions
Authors: Miyachi Shigetoh , Bürger Joachim , Kotzabasis Kiriakos , Thielmann Jens , Senger Horst
Published: August 2018

Quantum requirements of photosynthetic oxygen evolution at 679 nm, fluorescence emis­sion spectra at liquid nitrogen temperature (77 K) and fluorescence induction kinetics in the presence of DCM U, were measured in the cyanobacteria Anabaena variabilis M3, Anabaena variabilis ATCC 29413 and A nacystis nidulans R2, each grown under low-or high-CO2 conditions. Low -CO2 grown cells of the cyanobacteria showed a higher quantum requirement of photosynthetic oxygen evolution and a higher ratio o F710-740 to F680-700 fluorescence and a lower variable fluorescence in the presence of DCMU than high-CO2 grown cells. These findings indicate a change in excitation energy distribution in favour of photosystem I. The result might be an enhancement in ATP formation caused by cyclic electron flow which in turn provokes dissolved inorganic carbon (DIC) accumulation in these low-CO2 grown cells.
Phenolic Compounds as a Tool of Bioindication for Novel Forest Decline at Numerous Spruce Tree Sites in Germany
Authors: Richter Christine M. , Eis Ulrich , Wild Aloysius
Published: August 2018

Within a project that applied biochemical criteria to the diagnosis of damage to Norway spruce, 43 sites in western and eastern Germany showing only moderate tree damage were screened for the amounts of methanol soluble phenolic compounds in spruce needles. The concentrations of most of the main compounds-especially catechin-positively correlated with needle loss and the altitude of the site. It was also found that it is necessary to differenti­ate between trees younger and older than 60 years of age. The correlations between the increase of the phenolic compounds studied and the needle loss or the damage class are stronger in the younger trees, possibly implicating differences in metabolic state or distur­bances in protectective mechanisms in the older trees.
The Influence of Alkoxymethyl Purine and Pyrimidine Acyclonucleosides on Growth Inhibition of Kirkman-Robbins Hepatoma and Possible Mechanism of Their Cytostatic Activity
Authors: Modrzejewska Hanna , Greger Janusz , Dramiñski Marcin , Rutkowski Maciej
Published: August 2018

Newly synthesized allyloxymethyl purine and pyrimidine acyclonucleosides [Fig. 1, comp. 1-6] were tested in Syrian hamster, six days after heterotransplantations of Kirkman-Robbins hepatoma and compared with Th5, Th5P and PMT [Fig. 1, comp. 7 -9 ]. 48 hours after intraperitoneal (i.p.) administration of AMT and Th5 in a dose of 80 mg per kg body weight, these compounds reduced tumor weight by 42%, while AMU (in the same dose) by 30%. The inhibition of tumor weight is accompanied by a decrease in dThd and dGuo kinase activities in tumor cytosol by AMU (36% and 33%, respectively) by AM T (59% and 53%, respectively) and by Th5 (58% and 55%, respectively). AMU, AMT and Th5 are phosphorylated in vivo by kinases present in cytosol of growing hepatom a to mono, di and triphosphates, but allyloxymethyl residue of AMU and AMT is first hydrated to hydroxypropoxymethyl residue, having CH2OH group. The lack of phosphorylation of PMT in vivo (having saturated propoxymethyl residue) and phosphorylation of Th5P (when used as a substrate for dNMP kinase) only to Th5 diphosphate suggested that AMU, AM T and Th5 triphosphates are responsible for the inhibition of dTMP and dGMP synthesis.
Fatty Acid Composition of Some Ranunculaceae Seed Oils
Authors: Ucciani Eugène , Debal Alain , Gruber Michel , Wolff Robert L.
Published: August 2018

The fatty acid composition of seed oils of eight Ranunculaceae was determinated in order to characterize new sources of gamma-linolenic acid. Fatty acids were identified as fatty acid methyl esters (FAME) by capillary gas-liquid chromatography (GC) and capillary GC-Fourier transform infrared spectroscopy (FTIR). For trienic FAME the use of a cyanopropyl-polysiloxane stationary phase (CP-Sil 88) allowed the separation with high resolution of methyl ester of columbinic acid (trans-5,cis-9,cis-12 18:3) and gamma-linolenic acid (cis-6,cis-9,cis-12 18:3). The results confirmed the presence of columbinic acid in Thalictrum seed oils, and that of gamma-linolenic acid in Anemone and related species seed oils. The taxonomic subdivision of Ranunculaceae into sub-families and tribes, which resulted from morphological considerations, did not account for the above results.
The Autofluorescent Substance in the Posterior Flagellum of Swarmers of the Brown Alga Scytosiphon lomentaria
Authors: Yamano Kimiaki , Saito Hiroshi , Ogasawara Yukie , Fujii Shoko , Yamada Hiroko , Shirahama Haruhisa , Kawai Hiroshi
Published: August 2018

The flagellar autofluorescent substance of the brown alga Scytosiphon lomentaria , which is probably involved in the photoreception of the phototaxis of flagellate cells, was investi­ gated. 4′,5′-Cyclic FMN (1) was isolated from the extract of whole mature plants for the first time as a natural product. Since the concentration of 4′,5′-cyclic FMN (1) was considerably low in vegetative plants, which do not contain fluorescent flagella, this substance is consid­ered to correspond to the flagellar fluorescent substance.
Anthraquinones in the Leaf Beetle Trirhabda geminata (Chrysomelidae)
Authors: Kunze Arno , Witte Ludger , Aregullin Manuel , Rodriguez Eloy , Proksch Peter
Published: August 2018

Hydroxylated anthraquinones have been found to accumulate in different developmental stages of the chrysomelid beetle Trirhabda geminata. Eggs, larvae and adults were analyzed by HPLC and GC-MS. Each developmental stage analyzed contained 1,8-dihydroxy-3-methyl-anthraquinone (chrysophanol) and 1,8-dihydroxyanthraquinone (chrysazin). No anthraquinones were detected in the faeces of T. geminata. The level of stored anthraqui­ nones did not change during starvation. In the host plant of this specialist herbivore, the brittlebush Encelia farinosa (Asteraceae), anthraquinones were not detected. Possible biolog­ical functions of anthraquinones stored in T. geminata are discussed.
Hydrocarbon Distribution in Epicuticular Waxes of Five Euphorbia Species
Authors: Ahmad Waqar , Nazir Muhammad , Chaudhary Faqir Mohammad , Ahmad Ashfaq
Published: August 2018

The distribution pattern of hydrocarbons in the surface waxes of five species of Euphor­ biaceae, E.caducifolia, E.helioscopia, E.milii, E.royleana and E.tirucalli was studied. In addi­tion to homologous series of n-alkanes, minor quantities of unsaturated and branched hy­drocarbons were also detected. Some of the branched chain hydrocarbons could be explained as having originated from isoprene units and the substituents corresponding to diterpenes and triterpenes.
Reaction of Hypochlorous Acid with Hydrogen Peroxide and tert-Butyl Hydroperoxide. 1H NMR Spectroscopy and Chemiluminescence Analyses
Authors: Arnhold Jürgen , Panasenko Oleg M. , Schiller Jürgen , Arnold Klaus , Vladimirov Yurij A. , Sergienko Valerij I.
Published: August 2018

In contrast to the well-known reaction of hypochlorous acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between hypochlorous acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission result­ing from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations.

1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between hypochlorous acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction.

Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by hypochlorous acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric acid reactive products were observed.
Desialylation of Low Density Lipoprotein -Metabolic Function versus Oxidative Damage ?
Authors: Schlüssel E. H. , Elstner E. F.
Published: August 2018

Low density lipoproteins are generally considered to play a major role in the development of atherosclerotic vascular diseases. There is growing interest in LDL subspecies, especially in their density, carbohydrate content and oxidizability, which is supposed to enhance athero-genicity. We investigated the influence of desialylation on the resistance of the lipoprotein particles towards Cu(II) prooxidative activity.
On the Formation of Weddellite in Chamaecereus silvestrii, a Cactaceae Species from Northern Argentina
Authors: Monje P.V. , Baran E.J.
Published: August 2018

The isolation of well formed crystals of the biomineral weddellite (calcium oxalate dihydrate) from Chamaecereus silvestrii, a Cactaceae species found in the northern part of Argentina, is described. Infrared spectroscopic measurements allow an unambiguous characterization of the nature of the crystals. This is the first report of the presence of a biomineral in this plant species.
Enzyme-Modified Phytotoxic Structure of Thiadiazolidine Compounds
Authors: Senoo Satoshi , Iida Tetsuji , Shouda Kou , Sato Yukiharu , Nicolaus Beate , Böger Peter , Wakabayashi Ko
Published: August 2018

A simple model thiadiazolidine, 5-(4-methoxycarbonylmethylthio-phenylimino)-3,4-tetra-methylene-1,3,4-thiadiazolidin-2-one, was synthesized and its structural modification investigated using glutathione S-transferase (GST) and an esterase preparation isolated from Echinochloa utilis. The objective is a better understanding of the metabolic activation of peroxidizing thiadiazolidine compounds. The model thiadiazolidine with an ester group (thiadiazolidine ester) was isomerized by GST to a more phytotoxic triazolidine structure (triazolidine ester). Both the thiadiazolidine and the more active triazolidine ester were hydrolyzed by Echinochloa esterase to less active free acid compounds. 5-(4-carboxymethylthiophenylimino)-3,4-tetramethylene-1,3,4-thiadiazolidin-2-one (thiadiazolidine acid) and 4-(4-carboxy-methylthiophenyl)-1,2-tetramethylene-1,2,4-triazolidin-3-one-5-thione (triazolidine acid), respectively. The thiadiazolidine acid, however, was only slightly converted into the triazolidine acid in the presence of GST. It is concluded that the thiadiazolidine ester was isomerized in Echinochloa to give the triazolidine acid through the triazolidine ester. Since the triazolidine ester exhibited the highest phytotoxic peroxidizing activity GST is considered as an activating enzyme for phytotoxicity and esterase as a detoxifying enzyme to reduce phytotoxic activity. Accordingly, phytotoxic thiadiazolidine-ester type herbicides may be produced by an interplay of isomerizing GST and esterase activity contributing to herbicide selectivity among plant species.