bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation and Crystal Structures of the Hydrates of 18-Crown-6 [1]
Authors: Albert Antje , Mootz Dietrich 
Published: February 2015

Abstract
The melting diagram of the system 18-crown-6/water has been set up and the existence of four binary hydrates confirmed. Crystal structures have been determined for three of these, in addition to that for the hexahydrate already published. The hydrates are monoclinic, a tetrahydrate (previously reported as a 4.5-hydrate) with space group P21/c and Z = 2 formula units per unit cell, an octahydrate with I2/a and Z = 4, and a dodecahydrate with P21/n and Z= 2. In each structure the crown ether molecule has the (pseudo) D3d conformation common for many of its complexes, and is immediately hydrogen-bonded by a group of four water molecules in a similar, characteristic pattern. In the tetrahydrate, with one of the waters disordered, the total connectivity is that of a 1D chain, while the overall structures of the octa-and dodecahydrate are 3D networks. Four of the six independent water molecules in the dodecahydrate are linked with each other into a rare 2D ice-like layer.
Staphyloferrin B, a Citrate Siderophore of Ralstonia eutropha
Authors: Münzinger Maik , Taraz Kambiz , Budzikiewicz Herbert 
Published: February 2015

Abstract
The structure and stereochemistry of the siderophore isolated from the culture medium of Ralstonia eutropha (formerly Alcaligenes eutrophus) could be elucidated as staphyloferrin B by spectroscopic methods and chemical degradation. The relationship of the three species of the new genus Ralstonia is reflected in the observation that all three form citrate sidero-phores.
Flavonoids as Chemotaxonomic Markers for Erythroxylum ulei
Authors: Johnson Emanuel L. , Schmidt Walter F. 
Published: February 2015

Abstract
Leaf extracts of Erythroxylum ulei O. E. Schulz, produced six O-conjugated flavonoids. Three of the flavonoid aglycones were isoflavones, two were isoflavanones and the remainder a flavonol (quercetin). The major glycosides of these flavonols included mono-and dirham-nosides, mono-glucosides and galactosides with either 3̕ 4̕, or 7 linkage or a combination thereof. The two isoflavanones, in addition to being glycosylated, possessed a methyl group at position 2 of the C-ring. These flavonoids may be used as chemotaxonomic markers for the taxon.
Molecular Dynamics Modellization and Simulation of Water Diffusion through Plant Cutin
Authors: Matas Antonio , Heredia Antonio 
Published: February 2015

Abstract
A theoretical molecular modelling study has been conducted for cutin, the biopolyester that forms the main structural component of the plant cuticle. Molecular dynamics (MD) simulations, extended over several ten picoseconds, suggests that cutin is a moderately flexible netting with motional constraints mainly located at the cross-link sites of functional ester groups. This study also gives structural information essentially in accordance with previously reported experimental data, obtained from X -ray diffraction and nuclear magnetic resonance experiments. MD calculations were also performed to simulate the diffusion of water mole­cules through the cutin biopolymer. The theoretical analysis gives evidence that water perme­ation proceedes by a “hopping mechanism”. Coefficients for the diffusion of the water molecules in cutin were obtained from their mean-square displacements yielding values in good agreement with experimental data.
Effects of Antifungal Compounds on Conidial Germination and on the Induction of Appressorium Formation of Magnaporthe grisea
Authors: Eilbert Frank , Thines Eckhard , Anke Heidrun 
Published: February 2015

Abstract
Appressorium formation in germinating conidia of Magnaporthe grisea was induced on a hydrophilic (noninductive) surface by antifungal compounds. Respiratory inhibitors or un­ coupling agents such as strobilurins, antimycin A , myxothiazol, rotenone, pterulone A , and oligomycin A were particularly effective whereas sodium cyanide had no effect. Cyclosporin A was effective only at high concentrations. These differentiation-inducing effects were only observed at subfungicidal concentrations at which more than 50% of the germinating conidia formed appressoria. Cycloheximide, nystatin, amphotericin B, and papulacandin A did not induce appressoria. Different strains of M. grisea displayed the same overall response to the inhibitors, varying merely in the percentage of appressoria formed. A combination of the respiratory inhibitors with 2-phenyl-4H -1-benzopyran-4-one (flavone), diphenyleneiodonium (DPI), or salicylhydroxamic acid (SHAM), compounds which interfere with the cyanide-resistant respiration, resulted in a higher sensitivity of the strains towards the respiratory inhibitors, but had no effect on appressorium formation.
Study of the Topical Anti-Inflammatory Activity of Achillea ageratum on Chronic and Acute Inflammation Models
Authors: Gómez M. A. , Sáenz M. T. , García M. D. , Fernández M. A. 
Published: February 2015

We have produced a chloroform extract from Achillea which includes stigmasterol and sitosterol. By comparing it with the pure compounds an anti-inflammatory effect (with mouse ears) is assumed.
The topical anti-inflammatory effect of the chloroform extract from Achillea ageratum (Asteraceae)and of stigmasterol and β-sitosterol, isolated of this extract has been evaluated, against to 12-0-tetradecanoylphorbol acetate (TPA )-induced mouse ear edema, using simple (acute model) and multiple applications (chronic model) of the phlogistic agent. Myeloperoxydase activity also was studied in the inflamed ears.
In the acute model the extract exerted a dose-dependent effect. All the doses assayed (1, 3 and 5 mg/ear) significantly reduced the edema (50% , 66% and 82 % , respectively). The isolated sterols stigmasterol and β-sitosterol (with doses of 0.5 mg/ear) had similar effect as the extract with doses of 1 and 3 mg (59% and 65% respectively).
In the chronic model the anti-inflammatory effect generally was a more moderate one. The highest dose of the extract decreased the edema reduction to 26% with the highest dose of the extract applied. With the compounds the effect decreased to 36% with stigmasterol, and 40.6% with β-sitosterol.
Myeloperoxydase activity (MPO ) was reduced by the extract and the compounds in the acute model, however, in the chronic edema, the enzyme inhibition was very weak with all treatments even with the standard substance.
These results indicate that the chloroform extract of Achillea ageratum and some of the its components stigmasterol and β-sitosterol are more effective as topical anti-inflammatory agents in acute than in the chronic process and their action is markedly influenced by the inhibition of neutrophil migration into inflamed tissue.
Sterol Composition of the Black Sea Sponges Hymeniacidon sanguinea (Grant) and Halichondria panicea (Pallas)
Authors: Elenkov Ivayh , Popov Simeon , Andreev Stoitze 
Published: February 2015

Abstract
The sterol composition of Hymeniacidon sanguinea and Halichondria panicea from the Black Sea was investigated. Both sponges contain similar mixtures of stanols and of dietary Δ5-sterols. Main sterols appeared to be C27-sterols, which could be connected with a common diet for the both sponges. Saturated short side chain sterols have been found in Hymeniaci­don sanguinea. Three of them were novel for sponges. A possibility for the transformation of some dietary sterols into stands is discussed.
Ecto-Phosphatase Activities on the Cell Surface of the Amastigote Forms of Trypanosoma cruzi
Authors: Meyer-Fernandes José Roberto , Silva-Neto Mario Alberto da , Soares Mirna dos Santos , Fernandes Eloise , Vercesi Anibal Eugênio , Oliveira Mécia Maria de 
Published: February 2015

Abstract
Live Trypanosoma cruzi amastigotes hydrolyzed p-nitrophenylphosphate (PNPP), phos-pho-amino-acids and 32P-casein under physiologically appropriate conditions. PNPP was hy­drolysed at a rate of 80 nmol ·mg -1 ·h -1 in the presence of 5 mм MgCl2, pH 7.2 at 30 °C. In the absence of Mg2+ the activity was reduced 40% and we call this basal activity. At saturating concentration of PNPP, half-maximal PNPP hydrolysis was obtained with 0.22 mм MgCl2· Ca2+ had no effect on the basal activity, could not substitute Mg2+ as an activator and in contrast inhibited the PNPP hydrolysis stimulated by Mg2+ (I50 = 0.43 mм ) . In the absence of Mg2+ (basal activity) the stimulating half concentration (S0. 5) for PNPP was 1.57 mм , while at saturating MgCl2 concentrations the corresponding S0.5 for PNPP for Mg2+-stimulated phosphatase activity (difference between total minus basal phosphatase activity) was 0.99 mм . The Mg-dependent PNPP hydrolysis was strongly inhibited by sodium fluoride (NaF), vanadate and Zn2+ but not by tartrate and levamizole. The Mg-independent basal phosphatase activity was insensitive to tartrate, levamizole as well NaF and less inhibited by vanadate and Zn2+. Intact amastigotes were also able to hydrolyse phosphoserine, phos-phothreonine and phosphotyrosine but only the phosphotyrosine hydrolysis was stimulated by MgCl2 and inhibited by CaCl2 and phosphotyrosine was a competitive inhibitor of the PNPP hydrolysis stimulated by Mg2+. The cells were also able to hydrolyse 32P-casein phosphorylated on serine and threonine residues but only in the presence of MgCl2. These results indicate that in the amastigote form of T. cruzi there are at least two ectophosphatase activities, one of which is Mg2+ dependent and can dephosphorylate phospho-aminoacids and phosphoproteins under physiological conditions.
Notes: Activation of Hematoporphyrin in Alternating Magnetic Field: Possible Implications for Cancer Treatment
Authors: Babincová Melánia , Sourivong Phoumyphone , Leszczynska Danuta 
Published: February 2015

Abstract
A new mechanism of cell damage by alternating mag­netic field with hematoporphyrin is described. C6 gli­oblastoma cell suspensions were exposed to an alternat­ing magnetic field with frequency 180 kHz up to 60 min in the presence of hematoporphyrin in H2O and in D2O . The results presented suggest that an alternating mag­netic field is able to activate hematoporphyrin, and this method may be a basis for cancer treatment.
Pyrrolizidine Alkaloids from Echium rauwolfii and Echium horridum (Boraginaceae)
Authors: El-Shazly Assem , Abdel-All M. , Tei Andreas , Wink Michael 
Published: February 2015

Abstract
Echimidine was isolated from Echium rauwolfii and Echium horridum and identified by MS, 1H-and 13C NMR as a major alkaloid. In addition, structures of 12 minor alkaloids were inferred from GLC and GLC-MS analyses: 7-angeloylretronecine, 7-tigloylretronecine, lycopsamine, 7-acetyllycopsamine, uplandicine, 7-angeloyllycopsamine, 7-tigloyllycopsamine, tigloyl isomer of echimidine, 7-angeloyl-9-(2-methylbutyryl)retronecine, 7-tigloyl-9-(2-methylbutyryl)retronecine, 7-angeloyl-9-(2,3-dihydroxybutyryl)retronecine, and 7-tigloyl-9-(2,3-dihydroxybutyryl)retronecine. Both species had similar alkaloid profiles. Alkaloid extracts exhibited antibacterial effects with a MIC of 1.7 mg/ml in E. coli. Microscopic examination of E. coli treated with different subtoxic alkaloid concentrations (13-52 μg/ml) revealed extensive filamentation.
Phytotoxic and Photosynthetic Activities of Maduramicin and Maduramicin Methyl Ester
Authors: Gutiérrez-Lugo Maria Teresa , Lotina-Hennsen Blas , Farrés Amelia , Sánchez Sergio , Mata Rachel 
Published: February 2015

Abstract
The polyether antibiotic maduramicin and its methyl ester derivative inhibited photophos­ phorylation and proton uptake in isolated spinach chloroplasts. Both compounds also en­ hanced basal and phosphorylating electron transport and stimulated Mg2+-dependent AT­ Pase activity, therefore, they behave as uncouplers of photophosphorylation being the methyl ester derivative more potent than the parent compound. On the other hand, maduramicin inhibited germination and radicle elongation of several crop and weed species. In addition, the antibiotic caused phytotoxic injury and fresh weight reduction to 4-to-6 week old seed­ lings of two weed and two crop species when applied at 10-4 ᴍ by foliar application in the greenhouse.
Molecular Cloning and Spatial Expression of an ApL1 cDNA for the Large Subunit of ADP-Glucose Pyrophosphorylase from Arabidopsis thaliana
Authors: Kleszkowski Leszek A. , Sokolov Lubomir N. , Luo Cheng , Villand Per 
Published: February 2015

Abstract
A cDNA, A p L 1a , corresponding to a homologue of the large subunit of ADP-glucose pyrophosphorylase (AG Pase), has been isolated/characterised by screening a cDNA library prepared from leaves of Arabidopsis thaliana, followed by rapid amplification of cDNA 3′-ends (3′-RACE). Within the 1685 nucleotide-long sequence (excluding polyA tail), an open reading frame encodes a protein of 522 amino acids (aa), with a calculated molecular weight of 57.7 kDa. The derived aa sequence does not contain any discernible transit peptide cleavage site motif, similarly to two other recently sequenced full-length Arabidopsis homo-logues for AGPase, and shows ca. 58–78 % identity to homologous proteins from other plants/tissues. The corresponding gene was found (rosette and stem leaves, stems, flowers and fruits), consistent with its critical role in starch synthesis in
Sex Attractant of the Rosy Russian Gypsy Moth (Lymantria mathura Moore)
Authors: Oliver James E. , Dickens Joseph C. , Zlotina Marina , Mastro Victor C. , Yurchenko Galina I. 
Published: February 2015

Abstract
We report identification of the sex attractant of the rosy Russian gypsy moth, Lymantria mathura Moore. Two compounds, Z,Z,Z-3,6,9-nonadecatriene 1 and its monoepoxide Z,Z-(9S,10R)-9,10-epoxy-3,6-nonadecadiene 4a, have been identified from abdominal tip ex­ tracts of female moths based on coupled gas chromatography/electroantennogram detector responses and dose response curves. Single cell recordings showed that only one of the mo­ noepoxide enantiomers (S,R) was active. In field tests, both the (S,R)-monoepoxide and the racemate were active. This type of pheromone system, unusual for a Lymantriid, is more typical of those found in the families Arctiidae, Noctuidae and Geometridae.
Study of Propolis by High Temperature High Resolution Gas Chromatography-Mass Spectrometry
Authors: dos Santos Pereira Alberto , de Souza Ramos Mônica Freiman , Poças Elisa Suzana Carneiro , Dias Patricia Castro Moreira , dos Santos Elisabete Pereira , da Silva Joaquim Fernando Mendes , Cardoso Jari Nobrega , de Aquino Neto Francisco Radler 
Published: February 2015

Abstract
The underivatized hexane and acetone extracts of two propolis samples (from Brazil’s southwest) were analyzed by HT-HRGC (high temperature high resolution gas chromatogrphy) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds, including flavonoid aglycones, phenolic acids and high molecular weight compounds could be readily characterized in the crude extracts by HTHRGC-MS. HTHRGC and HTHRGC-MS were shown to be quick and informative tools for rapid analysis of crude extracts without need for prior derivatization and purification.
Phytochemical, Morphological, and Biological Investigations of Propolis from Central Chile
Authors: Valcic Susanne , Montenegro Gloria , Mujica Ana-Maria , Avila Guacolda , Franzblau Scott , Singh Maya P. , Maiese William M. , Timmermann Barbara N. 
Published: February 2015

Abstract
Propolis from Central Chile was investigated for its plant origin by microscopical analysis of pollen grains and leaf fragments found in the sample. The pollen grains that appear with significant higher frequency in the sample corresponded to four native and two introduced species, whereas leaf fragments corresponded to four native species. Seventeen phenolic com­ pounds that belong to the phenylpropane, benzaldehyde, dihydrobenzofuran, or benzopyran classes, were isolated from an organic extract that was found to have a moderate growth inhibitory activity against Mycobacterium avium , M. tuberculosis, and two strains of Staphylococcus aureus. The components responsible for activity were determined.
Antibacterial and Cytotoxic Natural and Synthesized Hydroquinones from Sponge Ircinia spinosula
Authors: Mihopoulos Nikos , Vagias Constantinos , Chinou Ioanna , Roussakis Christos , Scoullos Michael , Harvala Catherine , Roussis Vassilios 
Published: February 2015

Abstract
In order to check the structure-activity relationship and find more potent derivatives of the natural products 1 and 2 obtained from sponge Ircinia spinosula, a series of oxidation, hydrogenation, acetylation and methylation derivatives was prepared. All compounds (natural and synthetic ones) were screened for their cytotoxic and antibacterial activities. The biological studies showed a wide range of antibacterial activity even though only 2 and 2d showed a moderate cytotoxicity against the clone C98. The oxidation of the hydroquinone to quinone and the hydrogenation of the side-chain increased the antibacterial effect of the molecules.
A Joint Effect of Cationic and Anionic Amphiphilic Compounds on the Desorption of Calcium Ions from Lecithin Liposome Membranes
Authors: Kuczera Janina , Krai Teresa E. , Podolak Marian , Przestalski Stanisław 
Published: February 2015

Abstract
The aim of the work was to determine the synergism and antagonism of mixtures of the cationic amphiphilic compounds: N-benzyl-N,N-dimethyl-N-tetradecylammonium chloride (BD TA), N-benzyl-N,N-dimethyl-N-dodecylammonium chloride (BDDA), N-methyl-N-te-tradecyl-morpholinium bromide (MTM), N,N,N-trimethyl-N-tetradecylammonium bromide (TMTA) and those of tripropyltin chloride in a mixture with amphiphilic anionic compounds (a homologous series of sodium alkylsulfonates with n = 2, 4, 6, 8, 10, 12 and 14 alkyl carbon atoms) in the process of calcium ion desorption from liposome lecithin membranes. Radioactive labels and spin labels were used in the investigations.
All compounds studied caused an increase in the kinetic rate constant of calcium ion desorption from liposome membranes with increasing concentration. In case of mixtures containing cationic and anionic compounds both synergism and antagonism were observed. It was shown that the regulatory effect depended on the properties of both cationic and anionic compounds. A mixture of the most effective cationic compound (BDTA) with each of the anionic compounds decreased the effect. Mixtures of the remaining ammonium com­ pounds with sodium alkylsulfonates produced both synergism and antagonism. Anionic com­ pounds with short chains increased, and with longer chains decreased efficiency, while com­ pounds with comparable chains caused totally blocked desorption. A mixture of an organometallic compound having three short chains with anionic compounds gave a reversed effect: short-chain compounds caused a decreased and those with long-chains -increased efficiency of tripropyltin chloride.
Studies with spin labels supported the conclusion that the most important factor responsi­ ble for the regulatory effect is the molecular shape of the complexes formed in a mixture of both groups of compounds -a factor that determines membrane packing density
Strobilurin N and Two Metabolites Related to Chorismic Acid from the Fruit Bodies of Mycena crocata (Agaricales)
Authors: Buchanan Malcolm S. , Steglich Wolfgang , Anke Timm 
Published: February 2015

Abstract
Strobilurin N (1), a new member of the strobilurin family of antibiotics, has been isolated from the toadstool Mycena crocata, together with dehydrochorismic acid lactone (5) and 3-[1-carboxyvinyl)oxy]benzoic acid (6), which are closely related to chorismic acid (10). Their structures were determined mainly by 1H and 13C NMR spectroscopy. Interestingly, strobi­lurin N is the first strobilurin without antifungal activity
Organisation of Xanthophyll-Lipid Membranes Studied by Means of Specific Pigment Antisera, Spectrophotometry and Monomolecular Layer Technique Lutein versus Zeaxanthin
Authors: Gruszecki Wieslaw I. , Sujak Agnieszka , Strzalka Kazimierz , Radunz Alfons , Schmid Georg H. 
Published: February 2015

Abstract
The structure of the xanthophyll pigments lutein and zeaxanthin differs in the position of one double bond and refers to one of the ionon rings. Specific antibodies to zeaxanthin were used to analyse the localisation and orientation of these two xanthophyll pigments in lipid membranes formed with egg yolk lecithin. Bimolecular and monomolecular layers were used. Antibody-antigen interaction was demonstrated and analysed by the bathochromic shift of the absorption spectra of both pigments and by the increase of light-scattering of the pig- mented liposome suspension. It appeared that the extent of the spectral effects accompanying the interaction of the antiserum to zeaxanthin, injected to the liposome suspension which was pigmented with either zeaxanthin or lutein, was different in spite of their similar molecular structures. The results are interpreted in terms of a localisation and distribution of lutein, in the hydrophobic phase of liposomes within two essentially different pigment pools, one oriented horizontally and the other vertically with respect to the membrane plane. This inter- pretation is supported by the analysis of isotherms of the compression of monomolecular layers of lutein and zeaxanthin formed at the air-water interface and of mixed xanthophyll- lipid monolayers as well as by analysis of the penetration of antibody proteins dissolved in the subphase into the mixed xanthophyll-lipid films.
Influence of Climatic Factors on Annual Rings of Conifers
Authors: Ots Katri , Rauk Jtiri 
Published: February 2015

Abstract
Relationships of the width of annual rings of 75-85-year old Pinns sylvestris L. and Picea abies (L.) Karst, with average monthly temperature, amount of precipitation and a complex climatic indicator developed on their basis was studied against the background of pollution load in the zone influenced by a cement plant and in a control area. Multiple regression analysis (equations with two and three independent variables) showed a significant correlation between precipitation and temperatures with increment, especially for pine: however, the prediction capability of the models is modest, describing usually 35-40% of the variation in radial increment. The calculations suggest that precipitation amounts are more important and temperature parameters less important and can be replaced by one another in the models. A direct correlation with the pollution load can be observed: at probability (P) near zero the coefficients for precipitation were the highest (0.45-0.51) in the area strongly affected by the cement plant and the lowest (0.31 -0.35) in the weakly affected and control areas. In case of spruce shortage of air humidity during summer months was important for increment, especially so in the heavily polluted area.
High Activity of Binuclear Cobalt(II) Complex for Ethylene Evolution from 1-AminocycIopropane-1-carboxylic Acid in the Presence of Hydrogen Peroxide
Authors: Kobayashi Teruyuki , Sasaki Yumiko , Akamatsu Tetsuya , Ishii Toshihiro , Oda Yoshiaki , Masuda Hideki 
Published: February 2015

Abstract
The binuclear Co(II) and Mn(II) complexes with H5(HXTA). where H5(HXTA) repre­sents N,N′-(2-hydroxy-5-methyl-1,3-xylylene)bis(N-carboxymethylglycine), induced a strong ethylene evolution from 1-aminocyclopropane-l-carboxylic acid (ACC) in the presence of hydrogen peroxide, whereas activities of the corresponding Fe(III), Ni(II), and V(III) com­plexes were found negligible. Based on spectroscopic results and mass-spectral data it is proposed that a peroxide adduct of binuclear Co(II) (and Mn(II)) complex with η1-coordina­tion mode interacts with ACC, which is chelated to a binuclear cobalt complex leading to facile oxidative degradation of ACC and to evolution of ethylene.