bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibacterial Activity of Simple Coumarins: Structural Requirements for Biological Activity
Authors: Kayser Oliver , Kolodziej Herbert
Published: February 2015

The antibacterial activity of a series of simple coumarins was evaluated against 8 microorganisms, including three Gram-positive (Staphylococcus aureus, beta-hemolytic Streptococcus and Streptococcus pneumoniae) and five Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Haemophilus influenzae), using the microdilution broth method. The coumarins tested showed broad diversity regarding growth inhibitory activity with minimum inhibitory concentrations ranging from 0.9 to >12.4 μᴍ. This study, presenting the first systematic analysis of structure-activity relationships among this group of coumarins, revealed some interesting structural requirements. While coumarins with a methoxy function at C-7 and, if present, an OH group at either the C-6 or C-8 position are invariably effective against the spectrum of tested standard bacteria (Gram-negative microorganisms including the Gram-positive bacterium Staphylococcus aureus), the presence of an aromatic dimethoxy arrangement is apparently favourable against those mi­croorganisms which require special growth factors (beta-hemolytic Streptococcus, Streptococcus pneumoniae and Haemophilus influenzae). A combination of these structural features, two methoxy functions and at least one additional phenolic group as reflected by the highly oxygenated coumarins, identify promising candidates with antibacterial broad-spectrum activity.
Effects of Trehalose and Ethanol on Yeast Cytosolic Pyrophosphatase
Authors: Lopes Dahabada Helena José , Meyer-Fernandes José Roberto , Sola-Penna Mauro
Published: February 2015

Trehalose has been described to protect several enzymes against destabilizing conditions. This sugar is naturally accumulated by yeast as a stress protectant. A common stress condition that yeast is normally submitted is the presence of ethanol, the by-product of fermentation process of several yeast. In this paper we show the effects of trehalose and ethanol, alone or together, on yeast pyrophosphatase, and the effects of these compounds on inhibition and unfolding of pyrophosphatase promoted by urea. We show that both trehalose and ethanol inhibit pyrophosphatase in a dose-dependent manner, and that the presence of ethanol does not modify the inhibition promoted by trehalose as well as the presence of trehalose does not modify the inhibition promoted by ethanol. The effects of trehalose on pyrophosphatase are completely reversible, but the inhibition caused by ethanol was only partially reversible. Incubation of pyrophosphatase with 10% (v/v) ethanol promoted an inhibition of 15%, and the control activity was completely recovered after removal of ethanol. On the other hand, when pyrophosphatase was incubated with 20% (v/v) ethanol an inhibition of 40% of the control activity was observed which persisted after removal of ethanol. Ethanol also potentiates the inhibition of pyrophosphatase promoted by urea, and contributes for an irreversible inactivation and unfolding of pyrophosphatase in the presence of urea. Trehalose, that protects this enzyme against the inhibition and unfolding promoted by the chaotropic compound urea, was inefficient to protect against the effects of ethanol. Trehalose was also efficient to prevent an irreversible inactivation induced by urea.
Fluorescence Studies on Association of Human Translation Initiation Factor eIF4E with mRNA cap-Analogues
Authors: Wieczorek Zbigniew , Niedźwiecka-Kornaś Anna , Chlebicka Lidia , Jankowska Marzena , Kiraga Katarzyna , Stępiński Janusz , Dadlez Michał , Drabent Regina , Darżynkiewicz Edward , Stolarski Ryszard
Published: February 2015

Binding of a long series of mono- and dinucleotide analogues of the 7-methylguanosine containing 5′-mRNA-cap to human protein translation initiation factor eIF4E has been investigated by means of fluorescence. A new methodological approach in gathering and analysis of the fluorescence data provided us with very accurate values of the association equilibrium constant K and normalized, maximal quenching of the protein fluorescence ΔFmax, during titration of eIF4E by various cap-analogues. The results confirm participation of at least two conserved tryptophan residues of eIF4E in interaction with 7-methylguanine, as has been described recently for murine eIF4E, complexed with 7-methyl-GDP in crystal (Marcotrigiano et al., 1997, Cell 89, 951), and for yeast eIF4E, complexed with the same ligand in solution (Matsuo et al., 1997, Nature Struct. Biol. 4, 717). On the other hand binding by eIF4E of unmethylated guanine nucleotides and N2,N2,7-trimethylguanine containing nucleotides differ substantially from the way of binding of the regular mRNA-cap. Influence of the structural features of the cap-analogues, especially the type of the second nucleoside in the dinucleotide caps, on their association with eIF4E and biological activities in in vitro protein translation systems has been discussed in light of the known structures of the eIF4E -7- methyl-GDP complexes in crystal and solution.
α-Tocopherol Protection Against Drought-Induced Damage In Rosmarinus Officinalis L. And Melissa Officinalis L.
Authors: Munné-Bosch Sergi , Schwarz Karin , Alegre Leonor
Published: February 2015

Summer diurnal variations of photosynthesis and α-tocopherol content were measured in relation to natural drought in field-grown rosemary (Rosmarinus officinalis L.) and lemon balm (Melissa officinalis L.) plants. During the summer relative water contents (RWC) of ca. 40% in Rosmarinus officinalis and ca. 30% in Melissa officinalis were attained, indicating severe drought. Both species showed similar diurnal patterns of net CO2 assimilation rates (A) with a wide plateau of maximum photosynthesis at midday in the absence of drought and one peak of maximum photosynthesis early in the morning under drought conditions. Net CO2 assimilation rates decreased by ca. 75% due to drought in both species. Melissa

officinalis plants showed a significant decrease in the relative quantum efficiency of PSII photochemistry (ΦPSII), ratio of variable to maximum fluorescence yield (Fv/Fm) and chlorophyll content of leaves by ca. 25% under drought conditions at midday. In contrast, ΦPSII, Fv/Fm and chlorophyll content remained constant throughout the experiment in R. officinalis plants. Although the non-photochemical quenching of chlorophyll fluorescence increased from ca. 1.8 to 3 and the a-tocopherol content rose fifteen fold in both species in response to drought, only R. officinalis plants were able to avoid oxidative damage under drought conditions by the joint increase of carotenoids and α-tocopherol
A New Oxyprenyl Coumarin and Highly Methylated Flavones from the Exudate of Ozothamnus lycopodioides (Asteraceae)
Authors: Rumbero Angel , Arriaga-Giner Fco. Javier , Wollenweber Eckhard
Published: February 2015

A new oxyprenyl coumarin was isolated from the lipophilic exudate of Ozothamnus lycopodioides. Its structure was established as 7-(3,3′-dim ethylallyloxy)-5-hydroxy-6-methoxycoumarin from its UV, MS and NMR spectral data, especially two dimensional experiments. In addition to six earlier reported flavonols, we found four highly substituted flavones, including two rare methylenedioxyflavones.
Cytotoxic Activity of Flavonoids and Extracts from Retama sphaerocarpa Boissier
Authors: López-Lázaro Miguel , Martín-Cordero Carmen , Cortés Felipe , Piñero Joaquín , Ayuso María Jesús
Published: February 2015

Seven flavonoids isolated from chloroform , ethyl acetate and butanol extracts, obtained from the aerial parts of Retama sphaerocarpa, have been assessed for cytotoxic activity against three human cancer cell lines: TK-10 (renal adenocarcinom a), MCF-7 (breast adenocarcinom a) and UACC-62 (m elanom a), using the SRB assay. All of them , extracts and flavonoids, were actives in, at least, one of the three cell lines at the recom m ended N ational C ancer Institute doses. They produce a d ose-dependent inhibition of cell grow th at concentrations in the 10-6-10-4 ᴍ and 25 -250 μg/ml range for the flavonoids and extracts respectively, being the flavonol rhamnazin the most cytotoxic.
Genes Expressed in Ascochyta raftiei-Inoculated Chickpea Plants and Elicited Cell Cultures as Detected by Differential cDNA-Hybridization
Authors: Ichinose Yuki , Tiemann Karin , Schwenger-Erger Claudia , Toyoda Kazuhiro , Hein Frauke , Hanselle Thomas , Cornels Holger , Barz Wolfgang
Published: February 2015

In response to the exogenous application of elicitors and attempted invasion by pathogens, plants exhibit a wide range of defense reactions. To understand the defense mechanism s at the level of gene activation and deactivation, differential screenings were perform ed to isolate cDNA clones which are differentially expressed in pathogen-inoculated resistant chickpea plants and elicitor-treated cell cultures. A plenty of genes were isolated and arranged in 5 groups, namely defense-related pathways, signal transduction pathways, regulation of gene expression, catabolic pathways and primary metabolism . Most of these genes were activated although several genes were also found to be suppressed. We discuss the plausible functions of cDNA products in plant defense responses. The cDNA s provide a variety of tools to investigate m olecular mechanisms of defense responses and clearly reflect the massive genomic and metabolic changes which occur during manifestation of antimicrobial defense.
Catalytic Decomposition of 3-Chloroperoxybenzoic Acid by Immobilized Catalase in a Non-Aqueous Medium
Authors: Horozova Elena , Dimcheva Nina , Jordanova Zinaida
Published: February 2015

Catalytic activities of catalase (CAT) immobilized on graphite - GMZ™ , soot - “NORIT ” and “PM -100” to mediate decomposition of 3-Cl-C6H4COOOH (3-CPBA)in acetonitrile have been investigated. Under these conditions, the kinetic parameters Km, k, Ea, Vmax , and Zo were calculated. Conclusions on a probable mechanism of the catalytic process observed were drawn from the calculated values of ΔG*, ΔH*, and ΔS*. A quantitative UV-spectrophotometrical approach was used as the basic analytical tool. The electrochemical reduction of oxygen generated in enzyme catalysed 3-CPBA decomposition was examined with polarization curves method.
Oxidation of Plasmalogens Produces Highly Effective Modulators of Macrophage Function
Authors: Heinle Helmut , Gugeler Nadja , Felde Roswitha , Okech Dagmar , Spiteller Gerhard
Published: February 2015

Model derivatives of plasmalogens and chemically synthesized oxidative degradation products as found e.g. during oxidation of low density lipoproteins show strong effects on phagocytosis induced secretion of reactive oxygen species of macrophages which was measured by luminol-enhanced chemiluminescence. Whereas a plasmalogen epoxide showed enhancing effects in submicromolar range, inhibition was found with higher concentrations as well as with a-hydroxyaldehydes. The substances showed only little effects on the non-cellular ROSdependent chemiluminescence of the reaction between hydrogen peroxide and opsonized zymosan and no cytotoxic effects under the assay conditions used. These results show that oxidative modification and degradation of plasmalogens occuring also under pathophysiological situations in vivo produces effective modulators of macrophage function which could be important; e.g. during inflammation or atherogenesis.
Two New Flavonol Glycosides as DNA Topoisomerase I Poisons
Authors: López-Lázaro Miguel , Martín-Cordero Carmen , Ayuso María Jesús
Published: February 2015

Flavonoids are secondary plant metabolites whose anticancer properties are actually being studied from an epidemiological and pharmacological point of view. They are believed to be implicated in the lower risk of some forms of cancer observed in Asian countries, due to their capacity to control cell proliferation, to act on certain regulatory enzymes as protein kinases or topoisom erases. Based on these precedents, three flavonols isolated from a cytotoxic butanol extract from Retama sphaerocarpa Boissier have been assessed to study their topoisom erase I and II activity. Two new rhamnazin glycosides were found to have the ability to stabilize the cleavage com plex hum an D N A topoisom erase I at concentrations in the 100- 250 μm range, acting as topoisom ersase I poisons.
A Study on the Heterogeneity of the Light-Harvesting Complex II from Ectothiorhodospira sp. after Acid/Chaotropic Treatment
Authors: Buche Andre , Picorel Rafael
Published: February 2015

The light-harvesting complex II of the purple bacteria has two strong near infrared electronic absorption bands, around 800 (B800) and 850 (B850) nm, arising from the Qy transitions of bacteriochlorophyll a. It was previously reported that under some specific acid/chaotropic conditions the B850 bacteriochlorophylls of the light-harvesting complex II of Ectothiorhodospira sp. are strongly reorganised. Part of these pigments absorbs at 843 nm while another set absorbs around 858 nm. The current work should investigate whether a mix of two different complexes could generate the 843- and 858-nm bands. Acid/chaotropic conditions inducing the reorganisation of B850 were reproduced on a sample bound to an ionic-exchange column. The chromatographic pattern was found strongly homogeneous. The findings indicate that the heterogeneity of the reorganised B850 results from two forms of differently structured bacteriochlorophylls bound to the same polypeptide backbone.
Antioxidative Activity of Some Quaternary Ammonium Salts Incorporated into Erythrocyte Membranes
Authors: Kleszczyńska Halina , Sarapuk Janusz , Oświęcimska Małgorzata , Witek Stanisław
Published: February 2015

The antioxidative activity of two series of amphiphilic compounds from a group of quaternary ammonium salts has been investigated. They were so-called bifunctional surfactants synthesized to be used as common pesticides or as antioxidants. The latter application was to be ensured by providing the compounds studied with an antioxidant group. Studies on antioxidative possibilities of those compounds were performed on pig erythrocytes. Due to their hydrophobic parts, they anchor in the erythrocyte membrane and influence the degree of lipid oxidation in the erythrocyte membrane subjected to UV radiation. It was found that compounds of both series decreased the oxidation of the membrane lipids. The inhibition of this oxidation increased with the length of their hydrophobic chains up to fourteen carbon atoms. The compounds of the longest hydrophobic chains showed a somewhat weaker antioxidative activity. Of the two series studied compounds were more effective having bromide ions as counterions. The corresponding compounds of a second series (chlorides) protected erythrocyte significantly weaker against oxidation. The effect of the compounds on fluidity of the erythrocyte membrane has been studied in order to explain the oxidation results. Change in fluidity of the erythrocyte ghost membranes was found also dependent on length of the hydrophobic part of the compounds and was more pronounced in the case of bromide surfactants.

The final conclusion is that the compounds studied can be succesfully used as antioxidant agents of good efficacy.
Seasonal Variations in the Harpagoside Content of Scrophularia scorodonia L.
Authors: De Santos Galíndez Javier , Fernández Matellano Lidia , Díaz Lanza Ana María , Villaescusa Castillo Lucinda
Published: February 2015

Seasonal variations on the content of harpagoside in Scrophularia scorodonia L. (Scrophulariaceae) were investigated using plants collected monthly from January to December in 1995. During growth of this species the percentage of harpagoside was the highest during the maxim um development of the plant, specially in July. H arpagoside levels differed among leaves, stems and flowers of S. scorodonia. Leaves were distinguished from other plant parts by higher levels of harpagoside. Drying at ambient temperature influenced the yield of harpagoside com pared with the results of plant drying by microwave.
Probing Stimulants from the Rice Plant towards the Smaller Brown Planthopper, Laodelphax striatellus (Fallen) (Homoptera: Delphacidae)
Authors: Adjei-Afriyie Francis , Kim Chul-Sa , Takemura Masami , Ishikawa Masahiro , Tebayashi Shin-ichi , Horiike Michio
Published: February 2015

When adult males of the smaller brown planthopper, Laodelphax striatellus were fed on 2% crude rice (leaf and stem ) extract containing 15% sucrose there were characteristic stylet sheaths deposited on parafilm membrane. Further bioassays with the butanol-soluble fr. of the extract revealed that it is highly effective for the insects. When the butanol fr. was charged on an ODS open column and eluted in sequence with 20, 40 and 100% m ethanol in w ater, the ODS-40% m ethanol fr. was shown as the most effective one. F urther separation of the ODS-40% methanol fr. resulted in six effective components. These components acted to stimulate very high probing response on L. striatellus only when they are combined. This activity was found to be similar to those of the ODS-40% methanol fr. and the original crude rice plant extract. Two of the active components were identified as tricin 5-O-glucoside and tricin 7-O-glucoside, respectively, through spectroscopic analyses.
Iridoid Glucosides from Phlomis tuberosa L. and Phlomis herba-ventis L.
Authors: Alipieva Kalina Iv. , Jensen Soren R. , Franzyk Henrik , Handjieva Nedjalka V. , Evstatieva Ljuba N.
Published: February 2015

A new iridoid glucoside, 5-desoxysesamoside, was isolated from Phlomis tuberosa L. (Lamiaceae) together with three known iridoid glucosides sesamoside, shanziside methyl ester and lamalbid. Lamiide was found in P. herba-ventis ssp. pungens in high concentrations.
A New Class of Biflavonoids: 2'-Hydroxy genistein Dimers from the Roots of White Lupin
Authors: Sakasai Mitsuyoshi , Fukui Hiroki , Yamane Hideyuki , Kyaw Aung Naing , Tahara Satoshi
Published: February 2015

Two novel isoflavonoid dimers presumably originating from 2′-hydroxygenistein, 5,7,4′- trihydroxycoumaranochroman-4-one-(3→5‴)-5″,7″,2‴,4‴-tetrahydroxyisoflav- one (1, lupinalbisone A ) and 5,7,4′-trihydroxycoumaranochro-man-4-one-(3→6″)-5″,7″,2‴,4‴-tetrahydroxyisoflavone (2, lupinalbisone B) were isolated from the roots of Lupinus albus L., and their structures involving relative stereochemistry were elucidated by spectroscopic methods. Using horse radish peroxidase and 2′-hydroxygenistein (3) as the substrate revealed the formation of these dimers together with 5,7,4′-trihydroxycoumaronochromone (4, lupinalbin A ). Dimerization of 3 caused a remarkable increase of antifungal activity.
Systematic Study of High Molecular Weight Compounds in Amazonian Plants by High Temperature Gas Chromatography-Mass Spectrometry
Authors: Siqueira Denilson Soares de , Pereira Alberto dos Santos , Cabralb José Augusto , Ferreirab Carlos Alberto Cid , Neto Francisco Radler de Aquino
Published: February 2015

The fractions of hexane and dichloromethane extraction from marupá (Simaruba amara) and (Bertholletia excelsa) leaves were analyzed by HT-HRGC (high temperature high resolution gas chromatography) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds can be characterized including unusual high molecular weight com pounds.
Comparison of Headspace Techniques for Sampling Volatile Natural Products in a Dynamic System
Authors: Fäldt Jenny , Eriksson Mikael , Valterová Irena , Borg-Karlson Anna-Karin
Published: February 2015

Commonly used dynamic sorption techniques for collecting biologically active volatile compounds have been compared. Solid phase microextraction (SPME) using two types of fibers (polydimethylsiloxane, PDMS, 100 μm, and carbowax/divinylbenzene, CW/DVB, 65 μm) was compared to purge and trap methods (Porapak Q, Tenax TA and charcoal) and a technique based on absorption in methanol in a cooling bath. Sampling was done in a stream of purified air (20 ml/min) in a closed and temperature-regulated (27 °C) glass tube, passing over a capillary tube containing a hexane solution of tridecane, heptadecane, 1-octen-3-ol, 1- hexadecanol, ethyl tetradecanoate, α-pinene, linalool, terpinen-4-ol, cis-verbenol, verbenone, β-caryophyllene, E,E-farnesol, and geranylgeraniol. With all of the methods, the sampling was performed for a period of 30 min before extraction and analysis was done on a GC-FID system. In general, SPME gave a higher response for all compounds except for a-pinene, which was only extracted by the CW/DVB fiber. Purge and trap methods and methanol absorption gave the same response for all substances extracted. None of the methods extracted hexadecanol and geranylgeraniol under the conditions used. However, the SPME equipped with the PDMS coating extracted heptadecane, E,E-farnesol and ethyl tetradecanoate. Our results show that SPME, when selecting the fibers to fit the polarity and volatility of the compounds, is an outstanding extraction method compared to purge and trap and methanol absorption, especially for a qualitative analysis. The best conditions for storing fibers exposed to compounds of high volatility were at low temperatures (6 °C) in sealed vials, while the worst way was to leave the exposed fiber unprotected at room temperature (22 °C). The dynamic sampling system was effectively tested on a fruiting body of a polypore fungus ( Ganoderma applanatum) emitting 1-octen-3-ol, and again SPME showed to be the most sensitive technique.
Two-Dimensional TLC Separation and Mass Spectrometric Identification of Anthraquinones Isolated from the Fungus Dermocybe sanguinea
Authors: Räisänen Riikka , Björk Heikki , Hynninen Paavo H.
Published: February 2015

A new two-dimensional TLC technique was developed to separate substituted anthraquinones on silica plates using n-pentanol-pyridine-methanol (6:4:3, v/v/v) and toluene-ethyl acetate-ethanol-formic acid (10:8:1:2, v/v/v/v) as eluents. The good separation power of the new technique was demonstrated by applying it to the analysis of complex anthraquinone mixtures isolated from the Scandinavian Derm ocybe sanguinea. Emodin, physcion, endocrocin, dermolutein, dermorubin, 5-chlorodermorubin, emodin-1-β-D-glucopyranoside, dermocybin-1-β-D-glucopyranoside and dermocybin, and five new, earlier in D. sanguinea unidentified compounds, 7-chloroemodin, 5,7-dichloroemodin, 5,7-dichloroendocrocin, 4-hydroxyaustrocorticone and austrocorticone, were separated and identified on the basis of Rf values, UV/Vis spectra and mass spectra.
Investigations into Enzymes of Nitrogen Metabolism of the Ectomycorrhizal Basidiomycete, Suillus bovinus
Authors: Grotjohann Norbert , Kowallik Wolfgang , Huang Yi , Bäumen Andrea Schulte in den
Published: February 2015

Axenic mycelia of the ectomycorrhizal basidiomycete, Suillus bovinus, were grown in liquid media under continuous aeration with compressed air at 25 °C in darkness. Provided with glucose as the only carbohydrate source, they produced similar amounts of dry weight with ammonia, with nitrate or with alanine, 60-80% more with glutamate or glutamine, but about 35% less with urea as the respectively only exogenous nitrogen source. In crude extracts of cells from NH4
+-cultures, NADH -dependent glutamate dehydrogenase exhibited high aminating (688 nmol x mg protein-1 × min-1) and low deaminating (21 nmol x mg protein-1 × min-1) activities. Its Km-values for 2-oxoglutarate and for glutamate were 1.43 mᴍ and 23.99 mᴍ, respectively. pH-optimum for amination was about 7.2, that for deamination about 9.3. Glutamine synthetase activity was comparatively low (59 nmol x mg protein- 1 × min-1). Its affinity for glutamate was poor (K m = 23.7 mᴍ), while that for the NH4
+ replacing NH2OH was high (Km = 0.19 mᴍ). pH-optimum was found at 7.0. Glutamate synthase (= GOGAT) revealed similar low activity (62 nmol x mg protein-1 × min-1), Km-v alues for glutamine and for 2-oxoglutarate of 2.82 mᴍ and 0.28 mᴍ, respectively, and pH-optimum around 8.0. Aspartate transaminase (= GOT) exhibited similar affinities for aspartate (Km = 2.55 mᴍ) and for glutam ate (Km = 3.13 mᴍ) , but clearly different Km-values for 2-oxoglutarate (1.46 mᴍ) and for oxaloacetate (0.13 mᴍ) . A ctivity at optim um pH of about 8.0 was 506 nmol x mg protein-1 × min-1 for aspartate conversion, but only 39 nm ol x mg protein-1 × min-1 at optimum pH of about 7.0 for glutam ate conversion. A ctivity (599 nm ol x mg protein -1 × min-1 ), substrate affinities (Km for alanine = 6.30 mᴍ , for 2-oxoglutarate = 0.45 mᴍ) and pH-optimum (6 .5 -7 .5 ) proved alanine transaminase (= GPT) also im portant in distribution o f intracellular nitrogen. There was comparatively low activity of the obviously constitutive enzyme, urease, (42 nm ol x mg protein-1 × min-1 ) whose substrate affinity was rather high (Km = 0.56 mᴍ). Nitrate reductase proved substrate induced; activity could only be measured after exposure of the mycelia to exogenous nitrate. Routes of entry of exogenous nitrogen and tentative significance of the various enzymes in cell metabolism are discussed.
Novel Spiciferone Derivatives from the Fungus Drechslera hawaiiensis Isolated from the Marine Sponge Callyspongia aerizusa
Authors: Edrada Ru Angelie , Wray Victor , Berg Albrecht , Gräfe Udo , Sudarsono  , Brauers Gernot , Proksch Peter
Published: February 2015

From the marine sponge Callyspongia aerizusa collected from the Sea of Bali, Indonesia, fungal isolates of Drechslera hawaiiensis were obtained. Culture filtrates of the fungus yielded four spiciferone derivatives which include spiciferone A (1) and B (2), and two other novel derivatives including spiciferol A (3) which is an alcohol congener of spiciferone A (1) and compound 4 which is an monocyclic spiciferone congener featuring a butoxyl side chain. The structures of the novel compounds were established on the basis of NMR spectroscopic (1H ,13C, COSY) and mass spectrometric (EIMS) data.
Effect of Counterions on the Influence of Dodecyltrimethylammonium Halides on Thermotropic Phase Behaviour of Phosphatidylcholine Bilayers
Authors: Różycka-Roszak Bożenna , Pruchnik Hanna
Published: February 2015

Effects of dodecyltrimethylammonium chloride (DTAC), dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermotropic phase behaviour of phosphatidylcholine bilayers as well as on 1H NMR spectra were studied. In order to enhance the effect of counterions on water structure two series of experiments were performed. In the first one the surfactants were added to the water phase and in the other one directly to lipid phase (a mixed film was formed). The effects of particular surfactants on the main phase-transition temperature were more pronounced when they were added to the water phase (1st method) instead of the lipid phase (2nd method). Furthermore, in the case of the first method the transitions were found asymmetrical while in the second method nearly symmetrical. It is suggested that surfactant-poor and surfactant-rich domains are formed when surfactants are added to the water phase.
Site-Specific in vivo Targeting of Magnetoliposomes Using Externally Applied Magnetic Field
Authors: Babincová Melánia , Altanerová Veronika , Lampert Miloš , Altaner Čestmír , Machová Eva , rámka Miron Š , Babinec Peter
Published: February 2015

Human serum albumin labeled with technetium-99m was encapsulated together with magnetite particles into phosphatidylcholine/cholesterol liposomes. In order to investigate the stability of this complex and its ability to be used for magnetic drug targeting, the in-vivo distribution after intravenous administration in rats was estimated. For in-vivo targeting an SmCo permanent magnet with intensity ~ 0.3 5 T was attached near the right kidney. Difference between the relative radioactivity in the magnetically targeted right kidney (25.92±5.84%) and non-targeted left kidney (0.93±0.05%) is sufficiently high for relevant clinical applications.
A Neural Network Model for the Self-Organization of Cortical Grating Cells
Authors: Bauer Christoph , Burger Thomas , Stetter Martin , Lang Elmar W.
Published: February 2015

A neural network model with incremental Hebbian learning of afferent and lateral synaptic couplings is proposed,which simulates the activity-dependent self-organization of grating cells in upper layers of striate cortex. These cells, found in areas V1 and V2 of the visual cortex of monkeys, respond vigorously and exclusively to bar gratings of a preferred orientation and periodicity. Response behavior to varying contrast and to an increasing number of bars in the grating show threshold and saturation effects. Their location with respect to the underlying orientation map and their nonlinear response behavior are investigated. The number of emerging grating cells is controlled in the model by the range and strength of the lateral coupling structure.
Anachelin, the Siderophore of the Cyanobacterium Anabaena cylindrica CCAP 1403/2A
Authors: Beiderbeck Hans , Taraz Kambiz , Budzikiewicz Herbert , Walsby Anthony E.
Published: February 2015

A catecholate siderophore - anachelin - has been isolated from the cyanobacterium Anabaena cylindrica CCAP 1403/2A. The central part of the siderophore is a tripeptide consisting of ʟ-Thr, ᴅ-Ser and ʟ-Ser. Its C-terminus is linked amidically to a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-7,8-dihydroxyquinolinium system and its N-terminus to 6-amino-3,5,7-trihydroxyheptanoic acid. The 7-hydroxyl group of the latter is esterified with salicylic acid whose carboxyl group is condensed with the 6-amino group to an oxazoline ring. Anachelin is the first genuine siderophore of a cyanobacterium whose structure has been elucidated.
Sesquiterpene Lactones from Inula montana L.
Authors: González-Romero María A. , Villaescusa-Castillo Lucinda , Díaz-Lanza Ana M.
Published: February 2015

Aerial parts of Inula montana were investigated for its sesquiterpenoid composition. Five sesquiterpene lactones, isoinuviscolide, gaillardin, 1β-hydroxy-3β-acetoxy-eudesm-4(15), 11(13)-dien-12-8β-olide, pulchellin-C and pulchellin-E were identified for the first time in this plant. One of them, 1β-hydroxy-3β-acetoxy-eudesm-4(15),11(13)-dien-12-8β-olide, is a novel natural product. The structures of this compounds were established by 1D and 2DNMR spectroscopy.
Copper Accumulation and Phosphatase Activities of Aspergillus and Rhizopus
Authors: Tsekova Kolishka , Galabova Danka , Todorova Kristina
Published: February 2015

Copper accumulation and phosphatase activities of three Aspergillus species resistant to copper were compared to three copper-sensitive Rhizopus species. High level of acid phosphatases and decreased Cu2+-uptake were found with resistant in contrast to sensitive strains. The presence of copper(II) ions in the medium increased the production of acid phosphatases in the resistant A. niger and decreased their activity in the sensitive R. delemar. Copper ions inhibited the activity of A. niger cellular acid phosphatase with a Ki of 8.9x10-4 ᴍ and slightly activated the R. delemar enzyme.
Different Effects of Di- and Triphenyltin Compounds on Lipid Bilayer Dithionite Permeabilization
Authors: Gabrielska Janina , Kral Teresa , Langner Marek , Przestalski Stanislaw
Published: February 2015

Phenyltins are chemicals widely used in industry, hence their occurrence in the human environment is frequent and widespread. Such compounds include hydrophobic phenyl rings bonded to positively charged tin. This molecular structure makes them capable of adsorbing onto and penetrating through biological membranes, hence they are potentially hazardous. Two such compounds, diphenyltin and triphenyltin, show different steric constraints when interacting with the lipid bilayer. It has been demonstrated that these compounds are positioned at different locations within model lipid bilayers, causing dissimilarity in their ability to affect membrane properties. In this paper we present a study regarding the ability of these two phenyltins to facilitate the transport of S2O4
-2 ions across the lipid bilayer, evaluated by a fluorescence quenching assay. In concentration range of up-to 60 μm those compounds do not affect lipid bilayer topology, when evaluated by vesicle size distribution. Both phenyltins facilitate the transfer of S2O4
-2 across the model lipid bilayer, but the dependence of dithionite transport on phenyltin concentration is different for both. In principle, above 20 μm triphenyltin is more efficient in transfering ions across the lipid bilayer than diphenyltin.
Propolis from the Mediterranean Region: Chemical Composition and Antimicrobial Activity
Authors: Velikova Milena , Bankova Vassya , Sorkun Kadriye , Houcine Saadi , Tsvetkova Iva , Kujumgiev A.
Published: February 2015

The chemical composition of propolis from Bulgaria, Turkey, Greece and Algeria was investigated by GC-MS. All of them contained mainly flavonoids and esters of caffeic and ferulic acids, which indicated that their main source are buds of poplars of the taxonomic section Aegieros. Some Turkish samples contained a low percent of diterpenic acids, while in Algerian samples significant amounts of a hydroxyditerpenic acid (M=322, its structure not determined by its MS) were found. All samples showed significant antibacterial and weak to moderate antifungal activity.
I3-naringenin-II8-4′-OMe-eriodictyol: a New Potential Analgesie Agent Isolated from Rheedia gardneriana Leaves
Authors: Filho Valdir Cechinel , Silva Karina L. da , Souza Márcia M. de , Oliveira Ana E. , Yunes Rosendo A. , Guimarães Cláudio L. , Verdi Luiz G. , Simionatto Edesio L. , Monache Franco Delle
Published: February 2015

This paper describes the isolation, identification and analgesic activity of a new biflavonoid from Rheedia gardneriana leaves, which correspond to I3-naringenin-II8-4ʼ-OMe-eriodictyol (GB-2a-II-4ʼ-OMe) (1), with a methoxyl group in position 4 of ring-II. Its structure was determined by spectroscopic data and confirmed by an alkaline hydrolysis. Its analgesic effect was evaluated in a writhing test and a formalin test in mice. It was found that this compound exhibits potent and dose-related analgesic action in both experimental models, with ID50 ’s values of 4.5 μmol/kg against the writhing test and 8.2 and 6.8 μmol/kg against the first and second phase of the formalin test, respectively. It was several times more potent than some well-known analgesic drugs used as reference.
Antiherpes Virus Effect of the Red Marine Alga Polysiphonia denudata
Authors: Serkedjieva Julia
Published: February 2015

The water extract from the red marine alga Polysiphonia denudata (Dillwyn) Kütz. from the Bulgarian Black Sea coast selectively inhibited the reproduction of herpes virus type 1 and type 2 in cell cultures (EC50 = 8.7 to 47.7 mg/ml) as shown by the reduction of virusinduced cytopathic effect and viral infectivity. The virus-inhibitory effect was dose-related, strain-specific and depended on virus inoculum. The inhibition affected adsorption as well as the intracellular stages of viral replication. The presence of the extract throughout the whole replicative cycle was necessary for the full expression of the antiviral effect. In higher concentrations (MIC90 = 6.5 mg/ml) the extract exhibited strong extracellular virus inactivating activity.
Fatty Acids and Sterols from Cymbopogon martinii var. Motia Roots
Authors: Siddiqi Shahzad A. , Misra Laxminarain
Published: February 2015

The hexane and methanol extracts of the roots of Cymbopogon martinii var. motia have been investigated to afford mainly fatty acids and common sterols. A new hydroxy unsaturated fatty acid, namely, 16-hydroxypentacos- 14(z)-enoic acid, has also been isolated.
Lignans from Leaves of Rollinia mucosa
Authors: Estrada-Reyes Rosa , Alvarez C. Ana Laura , López-Rubalcava Carolina , Rocha Luisa , Heinze Gerardo , Moreno Julia , Martínez-Vázquez Mariano
Published: February 2015

A new furofuranic lignan named (+)-epimembrine together with known (+)-epieudesmine and (+)-epimagnoline were isolated from leaves of R. mucosa. Their structures were determined by spectroscopic data. Palmitone and a mixture of β-sitosterol and stigmasterol were also isolated.
Prenylated p-Coumarates from the Twigs of Phebalium rude subsp. amblycarpum (Rutaceae)
Authors: Girard Corinne , Colombain Michel , Muyard Frédéric , Bévalota Françoise , Tillequin François , Waterman Peter G.
Published: February 2015

Phebarudol, a novel prenylated p-coumarate, was isolated from the twigs of Phebalium rude Bartl. subsp. amblycarpum (F. Muell.) P. G. Wilson (Rutaceae) together with the two already known related compounds, werneria chromene and methyl demethoxywutaiensate. The structure of phebarudol was established by spectroscopic methods.
Antinociceptive Activity of the Natural Piperidine Alkaloid Hydrochlorides from Syphocampylus verticellatus
Authors: Miguel Obdulio G. , Santos Adair R. S. , Calixto João B. , Monache Franco Delle , Yunes Rosendo A.
Published: February 2015

In addition to 3′-methoxyluteolin and mixtures of sterols and triterpenes, the leaves of Syphocampylus Verticellatus yielded two piperidine alkaloid hydrochlorides, one of them has a novel structure. The alkaloids exhibit antinociceptive activity.
Cantleyoside-dimethyl-acetal and Other Iridoid Glucosides from Pterocephalus perennis – Antimicrobial Activities
Authors: Graikou Konstantia , Aligiannis Nektarios , Chinou Ioanna B. , Harvala Catherine
Published: February 2015

Cantleyoside-dimethyl-acetal (6), was isolated from the endemic Greek plant Pterocephalus perennis subsp. perennis in addition to five other known iridoid glucosides, loganin, loganic acid, cantleyoside, secologanin, and secologanin-dimethyl-acetal. The structure of these compounds was determined by all spectroscopic means mainly by NMR and MS techniques. The above compounds as well as their acetyl derivatives were tested against six Gram positive and negative bacteria and three pathogenic fungi.
Differences in the Activity of Superoxide Dismutase, Polyphenol Oxidase and Cu-Zn Content in the Fruits of Gordal and Manzanilla Olive Varieties
Authors: Hornero-Méndez Dámaso , Gallardo-Guerrero Lourdes , Jarén-Galán Manuel , Mínguez-Mosquera María Isabel
Published: February 2015

Activity of the enzymes superoxide dismutase (SOD) and polyphenol oxidase (PPO) as well as Cu-Zn content have been monitored during the thirteen weeks growth of both Gordal and Manzanilla olive variety fruits. These metalloenzymes, with Cu and Zn in the prostetic group, are involved in controlling the redox balance in the chloroplast environment. The results indicated that, under similar phenological and environmental conditions, there are periodic peaks of SOD activity in both varieties, followed by fluctuations in the copper content of the fruit. This was interpreted as a common and simultaneous response to situations of oxidative stress, and this response was more intense in the variety Gordal. The enzyme PPO showed an activity peak at start of growth and then practically disappeared. Thus, its activity cannot be correlated with situations of stress or with changes of Cu and Zn in the fruit.
Comparative X-Ray Studies on the Interaction of Carotenoids with a Model Phosphatidylcholine Membrane
Authors: Faculty of Chemical Sciences, University of Concepción, Casi Mario , Hidalgo Paulina , Strzalka Kazimierz , Kostecka-Gugala Anna
Published: February 2015

The interaction of structurally different carotenoids with a membrane molecular model was examined by X-ray diffraction. The selected compounds were β-carotene, lycopene, lutein, violaxanthin, zeaxanthin, and additionally carotane, a fully saturated derivative of β-carotene. They present similarities and differences in their rigidity, the presence of terminal ionone rings and hydroxy and epoxy groups bound to the rings. The membrane models were multibilayers of dipalmitoylphosphatidylcholine (DPPC), chosen for this investigation because the 3 nm thickness of the hydrophobic core of its bilayer coincides with the thickness of the hydrophobic core of thylakoid membranes and the length of the carotenoid molecules. Results indicate that the six compounds induced different types and degrees of structural perturbations to DPPC bilayers in aqueous media. They were interpreted in terms of the molecular characteristics of DPPC and the carotenoids. Lycopene and violaxanthin induced the highest structural damage to the acyl chain and polar headgroup regions of DPPC bilayers, respectively.
Influence of Different Light Intensities on the Content of Diosgenin, Lipids, Carotenoids and Fatty Acids in Leaves of Dioscorea zingiberensis
Authors: Li Huming , Radunz Alfons , He Ping , Schmid Georg H.
Published: February 2015

Cultivation of the climbing plant Dioscorea zingiberensis at a light intensity of 100 μE · m-2 · sec-1 yields three different phenotypes. Most of the plants grow as green phenotype (DzW). Two further forms differ in their leaf shape and leaf color. Whereas one type exhibits a more pointed leaf shape in the upper part of the plant with leaves appearing yellow-green with white stripes or hatchings (DzY), the other type shows a more round leaf shape with an intensive yellow-green color (DzT). These three plant types differ in their diosgenin content not only in their rhizomes but also in the chloroplasts. In the rhizomes the diosgenin content in the green form is 0.4%, in the DzY-form 0.6% and in the DzT-form even 1.3% of the dry weight. Furthermore, even in chloroplasts of the green DzW-form and of the DzY-form the presence of diosgenin was demonstrated. It occurs there as the epimeric form yamogenin. The DzT-form contains no yamogenin in its chloroplasts. Besides this, these plant forms differ in their chlorophyll and carotenoid content and in their fatty acid composition. Carotenoids increase from 1.3% of total lipids in the green phenotype to 3.3% in the DzYand to 4.2% in the DzT-form. This increase refers to _-carotene as well as to lutein and neoxanthin. The chlorophyll content in the green type is 8.1% and lower in the DzY-form with 7%. The highest chlorophyll content is found in the DzT-form with 12%. Fatty acids in the DzY-form and in the DzT-form have a more unsaturated character than in the green phenotype. The content of the monoenoic acid trans-hexadecenoic acid is considerably lower in both phenotypes when compared to the green phenotype. In both phenotypes the quantity of fatty acids with 16 carbon atoms is reduced, whereas fatty acids with 18 carbon atoms occur in higher concentration.

Cultivation of the green phenotype (DzW) at the three light intensities of 10, 100 and 270 μE · m-2 · sec-1 leads to changes of the diosgenin content in rhizomes, to an increase of leaf dry weight, to a reduction of the grana structure in chloroplasts and therewith to a decrease of the chlorophyll content. The total lipid content is highest under the cultivation at 100 μE · m-2 · sec-1 and reduced by 30% at 10 and 270 μE · m-2 · sec-1. Carotenoids, however, are highest in shaded plants (10 μE · m-2 · sec-1) and plants grown under high light conditions of 270 μE · m-2 · sec-1. At 100 μE · m-2 · sec-1 a decrease of saturated fatty acids is observed in comparison to plants grown under shaded conditions.
Cucurbitacin F in Seeds of Kageneckia angustifolia (Rosaceae)
Authors: Muñoza Orlando , Estevez-Braun Ana M. , Ravelo Angel G. , González Antonio G.
Published: February 2015

Cucurbitacin F and the cyanogenetic compounds prunasin were isolated and identified from the seeds of Kageneckia angustifolia.
Iridoid and Phenolic Glycosides from Wulfenia carinthiaca
Authors: Arnold Ulrike W. , Zidorn Christian , Ellmerer Ernst P. , Stuppner Hermann
Published: February 2015

Two new phenylpropanoid glycosides (2′-O-acetylplantamajoside and 2′-O, 6″-O-diacetylplantamajoside), a new iridoid glycoside (10-O-(cinnamoyl)-6′-O-(desacetylalpinosidyl)-catalpol), the two known iridoid glycosides globularin and isoscrophularioside, and the known phenylpropanoid glycoside platamajoside were isolated from the methanolic extract of the underground parts of Wulfenia carinthiaca. Structure elucidations were based on high-resolution mass spectrometry and extensive 1-D and 2-D NMR spectroscopy.
5-(2′-Oxoheptadecyl)-resorcinol and 5-(2′-Oxononadecyl)-resorcinol, Cytotoxic Metabolites from a Wood-Inhabiting Basidiomycete
Authors: Filip Patrick , Anke Timm , Sterner Olov
Published: February 2015

5-(2′-oxoheptadecyl)-resorcinol (1) and 5-(2′-oxononadecyl)-resorcinol (2) were isolated from fermentations of an imperfect basidiomycete. The structures of the compounds were determined by spectroscopic techniques. Both compounds exhibit cytotoxic effects against the human colon tumor cell lines COLO-320, DLD-1 and HT-29 and the human promyeloid leukemia cell line HL-60, the human leukemia T cell JURKAT, the human hepatocellular carcinoma cell line HEP-G2 as well as the J774 mouse macrophage cell line. The compounds induce morphological and physiological differentiation of HL-60 cells into granulocytes, which subsequently die by apoptosis.

Both compounds show no antibacterial and antifungal activity.
Photosynthetic Electron Transport Inhibition by 2-Substituted 4-Alkyl-6-benzylamino-1,3,5-triazines with Thylakoids from Wild-Type and Atrazine-Resistant Chenopodium album
Authors: Okano Ruiko , Ohki Aiko , Ohki Shinpei , Kohno Hitoshi , Rensen Jack J. S. van , Böger Peter , Wakabayashi Ko
Published: February 2015

The effect of 2-benzylamino-1,3,5-triazines on photosynthetic electron transport (PET) was measured with thylakoids isolated from atrazine-resistant, wild-type Chenopodium album, and spinach to find novel 1,3,5-triazine herbicides bearing a strong PET inhibition. The PET inhibition assay with Chenopodium (wild-type and resistant), yielded a resistance ratio (R/ W = I50 (resistant)/I50 (wild-type)) of 324 for atrazine while for benzylamino-1,3,5-triazine derivatives of diamino-1,3,5-triazines a R/W of 11 to 160 was found. The compounds having a benzylamino group at one of the amino groups in the diamino-1,3,5-triazines have a resistant ratio down to one half to 1/30 of the atrazine value. The average resistance ratio of 21 benzylamino derivatives of monoamino-1,3,5-triazines was found to be about 4.0. The inhibition of 21 benzylamino-1,3,5-triazines assayed with atrazine-resistant Chenopodium thylakoids, indicated by pI50 (R) -values, correlated well with the PET inhibition pI50 (W) of wildtype thylakoids from Chenopodium.
Continuous Decomposition of Sporopollenin from Pollen of Typha angustifolia L. by Acidic Methanolysis
Authors: Bubert Henning , Lambert Jörg , Steuernagel Stefan , Ahlers Friedhelm , Wiermann Rolf
Published: February 2015

Sporopollenin from the pollen of Typha angustifolia L. was exposed to a series of 36 subsequent acidic methanolysis procedures. The remaining decomposition products were investigated using several spectroscopic methods including Fourier transform infrared spectroscopy (FT-IR), solid state 13C nuclear magnetic resonance spectroscopy (13C-CPMAS-NMR) and X-ray photoelectron spectrometry (XPS). Substantial weight losses of the sporopollenin material occur after each acidic methanolysis step, while FT-IR and 13C-CPMAS-NMR spectra display no noticeable differences after 12, 24 and 36 steps. These findings are interpreted as a hint that the sporopollenin polymer has a uniform composition, i.e. relatively small monomer moieties of similar primary structure are present. Moreover, the weight losses account for the presence of substantial amounts of ether linkages in the sporopollenin polymer.