bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolism of Methoxychlor by the P450‐Monooxygenase CYP6G1 Involved in Insecticide Resistance of Drosophila melanogaster after Expression in Cell Cultures of Nicotiana tabacum
Authors: Joußen Nicole , Schuphan Ingolf , Schmidt Burkhard 
Published: March 2010

AbstractCytochrome P450 monooxygenase CYP6G1 of Drosophila melanogaster was heterologously expressed in a cell suspension culture of Nicotiana tabacum. This in vitro system was used to study the capability of CYP6G1 to metabolize the insecticide methoxychlor (=1,1,1‐trichloro‐2,2‐bis(4‐methoxyphenyl)ethane, 1) against the background of endogenous enzymes of the corresponding non‐transgenic culture. The Cyp6g1‐transgenic cell culture metabolized 96% of applied methoxychlor (45.8 μg per assay) within 24 h by demethylation and hydroxylation mainly to trishydroxy and catechol methoxychlor (16 and 17%, resp.). About 34% of the metabolism and the distinct formation of trishydroxy and catechol methoxychlor were due to foreign enzyme CYP6G1. Furthermore, methoxychlor metabolism was inhibited by 43% after simultaneous addition of piperonyl butoxide (458 μg), whereas inhibition in the non‐transgenic culture amounted to 92%. Additionally, the rate of glycosylation was reduced in both cultures. These results were supported by the inhibition of the metabolism of the insecticide imidacloprid (6; 20 μg, 24 h) in the Cyp6g1‐transgenic culture by 82% in the presence of piperonyl butoxide (200 μg). Due to CYP6G1 being responsible for imidacloprid resistance of Drosophila or being involved in DDT resistance, it is likely that CYP6G1 conveys resistance to methoxychlor (1). Furthermore, treating Drosophila with piperonyl butoxide could weaken the observed resistance phenomena.
Ioniols I and II, Tetracyclic Diterpenes with Antibacterial Activity, from Sphaerococcus coronopifolius
Authors: Smyrniotopoulos Vangelis , Vagias Constantinos , Rahman Mukhlesur M. , Gibbons Simon , Roussis Vassilios 
Published: March 2010

AbstractTwo naturally occurring diterpenes featuring unprecedented tetracyclic skeletons, ioniols I and II (1 and 2, resp.), along with two previously reported metabolites 3 and 4, were isolated from the organic extract of Sphaerococcus coronopifolius collected from the rocky coasts of Corfu island in the Ionian Sea. The structures of the new natural products, as well as their relative configuration, were elucidated on the basis of extensive spectral analysis, including 2D‐NMR experiments. The isolated metabolites were evaluated for their antibacterial activity against a panel of Staphylococcus aureus strains, which included multidrug‐resistant (MDR) and methicillin‐resistant Staphylococcus aureus (MRSA) strains.
Studies on the Redox Characteristics of Ferrioxamine E
Authors: Kazmi S. Arif , Shorter A. Lee , McArdle James V. , Ashiq Uzma , Jamal Rifat Ara 
Published: March 2010

AbstractThermodynamic parameters for the reduction of ferrioxamine E as calculated from redox potentials determined at four different temperatures were found to be ΔH≠=7.1±3.4 kJ mol−1 and ΔS≠=−146 J mol−1 K−1. The negative entropy value is large, because the decrease in the charge at the metal center and an increase in its ionic radius force the structure of the complex to become less rigid and resemble the desferrisiderophore. The hydrophilic groups of the system are now (relatively more) available for solvent interaction. Thus, a large negative entropy change accompanies the reduction of the complex. Kinetics of reduction of ferrioxamine by VII, CrII, EuII, and dithionite were measured at different temperatures and by dithionite at different pH values. The CrII and EuII reactions proceed by an inner‐sphere mechanism and have second‐order rate constants at 25° of 1.37×104 and 1.23×105 M−1 s−1, respectively. For the VII reduction, the corresponding rate constant was 1.89×103 M−1 s−1. The activation parameters for the VII reduction were ΔH≠ = 8.3 kJ mol−1; ΔS≠ =−154 J mol−1 K−1. These values are indicative of an outer‐sphere mechanism for VII reduction. The reduction by dithionite is half order in dithionite concentration indicating that SO$\rm{{_{2}^{-}}}$. is the sole reducing species. log of reduction rate constants of different trihydroxamates by this reductant were correlated with their respective redox potentials, and the variation was found to be in approximate correspondence with the expectations of Marcus relationship.
Fragrant Volatile Compounds in the Liverwort Drepanolejeunea madagascariensis (Steph.) Grolle: Approach by the HS‐SPME Technique
Authors: Gauvin‐Bialecki Anne , Ah‐Peng Claudine , Smadja Jacqueline , Strasberg Dominique 
Published: March 2010

AbstractThree populations of the epiphyllous liverwort Drepanolejeunea madagascariensis collected in the cloud forests of Reunion Island (Mascarene Archipelago) were investigated for their volatile compounds, because of the pleasant, sweet, warm, woody‐spicy, and herbaceous fragrance, slightly reminiscent of dill, of this species. By applying the headspace solid‐phase microextraction (HS‐SPME) technique coupled to GC/MS analysis, 34 compounds were detected in total, with p‐menth‐1‐en‐9‐ol (28.8–43.5%), limonene (10.5–14.7%), β‐phellandrene (8.8–11.6%), and the so‐called dill ether (8.5–16.6%) as the main components. The presence of 1‐epi‐α‐pinguisene confirms the possible use of pinguisane‐type sesquiterpenoids as a characteristic chemical marker for the order Jungermanniales.
Cytotoxic Steroidal Saponins from the Rhizomes of Tacca integrifolia
Authors: Shwe Htay Htay , Aye Mye , Sein Myint Myint , Htay Khin Than , Kreitmeier Peter , Gertsch Jürg , Reiser Oliver , Heilmann Jörg 
Published: March 2010

AbstractThree new steroid saponins (3β,25R)‐spirost‐5‐en‐3‐yl 6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→4)‐6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (1), (3β,22R,25R)‐26‐(β‐D‐glucopyranosyloxy)‐22‐hydroxyfurost‐5‐en‐3‐yl 6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (3), and (3β,22R,25R)‐26‐(β‐D‐glucopyranosyloxy)‐22‐hydroxyfurost‐5‐en‐3‐yl 6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→4)‐6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (5), as well as the new pregnane glycoside (3β,16β)‐3‐{[6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranosyl]oxy}‐20‐oxopregn‐5‐en‐16‐yl (4R)‐5‐(β‐D‐glucopyranosyloxy)‐4‐methylpentanoate (6), were isolated from the rhizomes of Tacca integrifolia together with two known (25R) configurated steroid saponins (3β,25R)‐spirost‐5‐en‐3‐yl 6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (2) and (3β,22R,25R)‐26‐(β‐D‐glucopyranosyloxy)‐22‐methoxyfurost‐5‐en‐3‐yl 6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐[6‐deoxy‐α‐L‐mannopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (4). The cytotoxic activity of the isolated compounds was evaluated in HeLa cells and showed the highest cytotoxicity value for compound 2 with an IC50 of 1.2±0.4 μM. Intriguingly, while compounds 1–5 exhibited similar cytotoxic properties between 1.2±0.4 (2) and 4.0±0.6 μM (5), only compound 2 showed a significant microtubule‐stabilizing activity in vitro.
A New Prenylated Flavanonol from Seseli annuum Roots Showing Protective Effect on Human Lymphocytes DNA
Authors: Vučković Ivan , Vajs Vlatka , Stanković Miroslava , Tešević Vele , Milosavljević Slobodan 
Published: March 2010

AbstractA new prenylated flavanonol named seselinonol (1) was isolated from the roots of Seseli annuum, together with the well‐known biologically active polyacetylenes falcarinol (2) and falcarindiol (3), and the prenylated furanocoumarin phellopterin (4). Its structure was elucidated by extensive spectroscopic analysis, including HR‐ESI‐MS, 1D‐ and 2D‐NMR. Seselinonol and phellopterin were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin‐B blocked micronucleus (CBMN) assay. The new compound exerted a beneficial effect by decreasing DNA damage of human lymphocytes.
Effect of Crossbreeding on the Chemical Composition and Biological Characteristics of Tunisian New Olive Progenies
Authors: Rjiba Imed , Dabbou Samia , Gazzah Nouredine , Hammami Mohamed 
Published: March 2010

AbstractOlive fruit characteristics (weight, pulp/stone ratio, and oil and moisture content) and the iodine value (IV) of 31 new olive progenies (Olea europaea L.) were determined. To evaluate the effect of the genetic variability on these parameters, the new olive progenies, obtained through cross‐pollination between Tunisian and Mediterranean olive cultivars, were planted in a selected grove guaranteeing the homogeneity of the pedologic and climatic conditions. A strong genetic effect and significant differences between genotypes were obtained for the IV and the fruit characteristics evaluated. Discriminant analysis was used to classify the new progenies as distinct from each other, based on their IV, and their pulp and stone weight. An almost full discrimination of the olives from different genotypes was only achieved when the fruit characteristics (pulp and stone weight) and the IV data were analyzed together.
Oligonucleotide N3′→P5′ Phosphoramidates and Thio‐Phoshoramidates as Potential Therapeutic Agents
Authors: Gryaznov Sergei M. 
Published: March 2010

AbstractNucleic acids analogues, i.e., oligonucleotide N3′→P5′ phosphoramidates and N3′→P5′ thio‐phosphoramidates, containing 3′‐amino‐3′‐deoxy nucleosides with various 2′‐substituents were synthesized and extensively studied. These compounds resist nuclease hydrolysis and form stable duplexes with complementary native phosphodiester DNA and, particularly, RNA strands. An increase in duplexes' melting temperature, ΔTm, relative to their phosphodiester counterparts, reaches 2.2–4.0° per modified nucleoside. 2′‐OH‐ (RNA‐like), 2′‐O‐Me‐, and 2′‐ribo‐F‐nucleoside substitutions result in the highest degree of duplex stabilization. Moreover, under close to physiological salt and pH conditions, the 2′‐deoxy‐ and 2′‐fluoro‐phosphoramidate compounds form extremely stable triple‐stranded complexes with either single‐ or double‐stranded phosphodiester DNA oligonucleotides. Melting temperature, Tm, of these triplexes exceeds Tm values for the isosequential phosphodiester counterparts by up to 35°. 2′‐Deoxy‐N3′→P5′ phosphoramidates adopt RNA‐like C3′‐endo or N‐type nucleoside sugar‐ring conformations and hence can be used as stable RNA mimetics. Duplexes formed by 2′‐deoxy phosphoramidates with complementary RNA strands are not substrates for RNase H‐mediated cleavage in vitro. Oligonucleotide phosphoramidates and especially thio‐phosphoramidates conjugated with lipid groups are cell‐permeable and demonstrate high biological target specific activity in vitro. In vivo, these compounds show good bioavailability and efficient biodistribution to all major organs, while exerting acceptable toxicity at therapeutically relevant doses. Short oligonucleotide N3′→P5′ thio‐phosphoramidate conjugated to 5′‐palmitoyl group, designated as GRN163L (Imetelstat), was recently introduced as a potent human telomerase inhibitor. GRN163L is not an antisense agent; it is a direct competitive inhibitor of human telomerase, which directly binds to the active site of the enzyme and thus inhibits its activity. This compound is currently in multiple Phase‐I and Phase‐I/II clinical trials as potential broad‐spectrum anticancer agent.
Locked Nucleic Acids: Promising Nucleic Acid Analogs for Therapeutic Applications
Authors: Veedu Rakesh N. , Wengel Jesper 
Published: March 2010

AbstractLocked Nucleic Acid (LNA) is a unique nucleic‐acid modification possessing very high binding affinity and excellent specificity toward complementary RNA or DNA oligonucleotides. The remarkable properties exhibited by LNA oligonucleotides have been employed in different nucleic acid‐based therapeutic strategies both in vitro and in vivo. Herein, we highlight the applications of LNA nucleotides for controlling gene expression.
Erythropoietin induces nuclear translocation of Nrf2 and heme oxygenase‐1 expression in SH‐SY5Y cells
Authors: Genc Kursad , Egrilmez Mehtap Y. , Genc Sermin 
Published: March 2010

AbstractErythropoietin (Epo) exerts neuroprotective, glioprotective, and vascular protective effects in the nervous system. However, the mechanisms of the cytoprotective effect of Epo have not been fully clarified. Here, we investigated whether Epo affects the transcription and activation of nuclear factor erythroid 2‐related factor 2 (Nrf2), which is a key transcription factor of the cellular anti‐oxidant defense system, and mRNA expression of its target genes including heme oxygenase‐1 (HO‐1). Epo was added to SH‐SY5Y cells at 1 U mL−1 and cultures were incubated for 24 h and then mRNA expression of Nrf2 target genes were analyzed with real‐time PCR. SH‐SY5Y cells were incubated with Epo at different time points and the nuclear and cytoplasmic levels of Nrf2 protein expression were examined by Western blotting and immunohistochemistry. Specific inhibitors of mitogen‐activated protein kinases (MAPKs) and phosphatidylinositol‐3 kinase (PI3K) were used to find out the possible signaling pathways that mediate the activating effect of Epo on Nrf2 activation. In cultured human SH‐SY5Y neuroblastoma cells, Western blotting, immunohistochemistry, and real‐time PCR analysis demonstrated that Epo‐induced nuclear translocation of Nrf2 and upregulates HO‐1 expression. Inhibitors of MAPKs and PI3K decreased Epo‐induced nuclear translocation of Nrf2 and HO‐1 mRNA expression. These results suggest that Epo induces neural HO‐1 expression through the activation of PI3K, MAPK, and Nrf2 pathways, and this may unveil a novel mechanism which mediates the cytoprotective responses elicited by Epo. Copyright © 2010 John Wiley & Sons, Ltd.
Bis(phosphinimino)methanide Borohydride Complexes of the Rare‐Earth Elements as Initiators for the Ring‐Opening Polymerization of ε‐Caprolactone: Combined Experimental and Computational Investigations
Authors: Jenter Jelena , Roesky Peter W. , Ajellal Noureddine , Guillaume Sophie M. , Susperregui Nicolas , Maron Laurent 
Published: March 2010

AbstractRare‐earth‐metal borohydrides are known to be efficient catalysts for the polymerization of apolar and polar monomers. The bis‐borohydrides [{CH(PPh2NSiMe3)2}La(BH4)2(THF)] and [{CH(PPh2NSiMe3)2}Ln(BH4)2] (Ln=Y, Lu) have been synthesized by two different synthetic routes. The lanthanum and the lutetium complexes were prepared from [Ln(BH4)3(THF)3] and K{CH(PPh2NSiMe3)2}, whereas the yttrium analogue was obtained from in situ prepared [{CH(PPh2NSiMe3)2}YCl2]2 and NaBH4. All new compounds were characterized by standard analytical/spectroscopic techniques, and the solid‐state structures were established by single‐crystal X‐ray diffraction. The ring‐opening polymerization (ROP) of ε‐caprolactone initiated by [{CH(PPh2NSiMe3)2}La(BH4)2(THF)] and [{CH(PPh2NSiMe3)2}Ln(BH4)2] (Ln=Y, Lu) was studied. At 0 °C the molar mass distributions determined were the narrowest values (M̄w/M̄n=1.06–1.11) ever obtained for the ROP of ε‐caprolactone initiated by rare‐earth‐metal borohydride species. DFT investigations of the reaction mechanism indicate that this type of complex reacts in an unprecedented manner with the first BH activation being achieved within two steps. This particularity has been attributed to the metallic fragment based on the natural bond order analysis.
Triazolyl Azabicyclo[3.1.0]hexanes: a Class of Potent and Selective Dopamine D3Receptor Antagonists
Authors: Bonanomi Giorgio , Braggio Simone , Capelli Anna Maria , Checchia Anna , Di Fabio Romano , Marchioro Carla , Tarsi Luca , Tedesco Giovanna , Terreni Silvia , Worby Angela , Heibreder Christian , Micheli Fabrizio 
Published: March 2010

AbstractHerein we report a detailed description of the structure–activity relationships for a novel series of “C‐linked” 1,2,4‐triazolylazabicyclo[3.1.0]hexanes. These derivatives are endowed with very high in vitro affinity and selectivity for the dopamine D3receptor. An optimization with respect to undesired affinity toward the hERG potassium channel is also reported. Members of this compound series also show excellent in vitro and in vivo pharmacokinetic properties.
Fixation for distributed clustering processes
Authors: Hilário M. R. , Louidor O. , Newman C. M. , Rolla L. T. , Sheffield S. , Sidoravicius V. 
Published: March 2010

AbstractWe study a discrete‐time resource flow in
\input amssym ${\Bbb Z}^d $
where wealthier vertices attract the resources of their less rich neighbors. For any translation‐invariant probability distribution of initial resource quantities, we prove that the flow at each vertex terminates after finitely many steps. This answers (a generalized version of) a question posed by van den Berg and Meester in 1991. The proof uses the mass transport principle and extends to other graphs. © 2010 Wiley Periodicals, Inc.
Vortex energy and 360° Néel walls in thin‐film micromagnetics
Authors: Ignat Radu , Knüpfer Hans 
Published: March 2010

AbstractWe study the vortex pattern in ultrathin ferromagnetic films of circular crosssection. The model is based on the following energy functional:

for in‐plane magnetizations m: B2 → S1 in the unit disc
$\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}B^2 \subset \R^2$. The avoidance of volume charges ▿ · m ≠ 0 in B2 and surface charges m · ν ≠ 0 on δB2 leads to the formation of a vortex in the limit ε → 0. At the level ε > 0 the vortex is regularized by the formation of a 360° Néel wall (a one‐dimensional transition layer with core of scale ε) concentrated along a radius of B2. We derive the limiting energy of the vortex by matching upper and lower bounds. Our analysis on the lower bound is based on a dynamical system argument and an interpolation inequality with sharp leading‐order constant, while the upper bound uses the leading‐order energy for 360° Néel walls. © 2010 Wiley Periodicals, Inc.
Communication via responsibility reporting and its effect on firm value in Finland
Authors: Schadewitz Hannu , Niskala Mikael 
Published: March 2010

Abstractn this paper, we first analyzed the responsibility reporting literature with an emphasis on the linkage between responsibility reporting and a firm's performance and valuation. Based on the literature review, we developed a research question: How does communication via responsibility reporting affect firm value? We analyzed the market valuation of listed Finnish firms through a conventional valuation model combined with responsibility reporting. The starting point for our valuation was the Ohlson model. We expanded upon the conventional valuation by studying whether communication via responsibility reporting is related to firm valuation. Our research question is linked to the broader academic question of whether earnings worth as an information source has been erased over the last few years. In addition, we contribute to the literature that tries to understand the link between corporate social responsibility and firm performance/share performance. Specifically, we focused on responsibility reporting according to the Global Reporting Initiative (GRI) and especially on whether the existence of these reports provides a further explanation for firm value.Our sample was a population type that covered all listed Finnish firms that have adopted GRI. No other responsibility reporting practice was used by listed firms in their responsibility reporting communication during the years 2002–2005. The other necessary information for valuation models was obtained from Thomson Financial Services (commercial database).The applied model supported the conclusion that communication via GRI responsibility reporting is an important explanatory factor for a firm's market value. The result indicates that responsibility reporting is a part of a firm's communication tools in order to decrease information asymmetry between managers and investors. In other words, GRI responsibility reporting is called for in order to produce a more precise market valuation of a firm. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
miRNAs give worms the time of their lives: Small RNAs and temporal control in Caenorhabditis elegans
Authors: Resnick Tamar D. , McCulloch Katherine A. , Rougvie Ann E. 
Published: March 2010

AbstractAlteration in the timing of particular developmental events can lead to major morphological changes that have profound effects on the life history of an organism. Insights into developmental timing mechanisms have been revealed in the model organism Caenorhabditis elegans, in which a regulatory network of heterochronic genes times events during larval development, ensuring that stage‐specific programs occur in the appropriate sequence and on schedule. Developmental timing studies in C. elegans led to the landmark discovery of miRNAs and continue to enhance our understanding of the regulation and activity of these small regulatory molecules. Current views of the heterochronic gene pathway are summarized here, with a focus on the ways in which miRNAs contribute to temporal control and how miRNAs themselves are regulated. Finally, the conservation of heterochronic genes and their functions in timing, as well as their related roles in stem cells and cancer, are highlighted. Developmental Dynamics 239:1477–1489, 2010. © 2010 Wiley‐Liss, Inc.
CH4 flux from peatlands: a new measurement method
Authors: Baird Andrew J. , Stamp Imelda , Heppell Catherine M. , Green Sophie M. 
Published: March 2010

AbstractPeatlands are important sources of atmospheric CH4, a potent greenhouse gas. Identifying the controls on CH4 flux from peatlands requires detailed investigation of fluxes at small scales (the microform scale) where flux chambers are best deployed for measurement. Using chambers presents challenges, not least that of how the CH4 concentration in chamber gas should be measured. Current field approaches usually involve either (i) online measurement with a flow‐through laser absorption spectroscopy instrument or (ii) online or offline analysis of CH4 by gas chromatography–flame ionization detector (GC‐FID) analysis. Online measurement restricts the number of chambers that can be monitored to c. 10 and their spatial spread to a distance of 10–20 m from the CH4 analyser and is not suited to large‐scale studies. GC‐FID may present logistical difficulties when conducting research at remote sites because of the need for frequent calibration and, hence, calibration gases. Generally, it is not suited to non‐laboratory applications. An alternative is to analyse syringe samples of chamber gas near the field site using a modified laser spectroscopy instrument. We show how such a modification may be made. The theory of our modification is presented, as are the results obtained using it. It is shown that the instrument with the modification compares favourably with GC‐FID and can be used near remote field sites in the absence of laboratory facilities. We present flux data from a peatland in Wales, where the flux‐chamber CH4 concentrations were obtained using the modified instrument. Copyright © 2010 John Wiley & Sons, Ltd.