bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkaloids from Corydalis saxicola and Their Anti‐Hepatitis B Virus Activity
Authors: Li Hui‐Liang , Han Ting , Liu Run‐Hui , Zhang Chuan , Chen Hai‐Sheng , Zhang Wei‐Dong 
Published: May 2008

AbstractEight protoberberine‐type alkaloids and two indole alkaloids were isolated from the MeOH extracts of the herb Corydalis saxicola Bunting (Papaveraceae). Their structures were identified as dehydrocavidine (1), dehydroapocavidine (2), dehydroisoapocavidine (3), berberine (4), dehydroisocorypalmine (5), coptisine (6), tetradehydroscoulerine (7), berbinium (8), 1‐formyl‐5‐methoxy‐6‐methylindoline (9), and 1‐formyl‐2‐hydroxy‐5‐methoxy‐6‐methylindoline (10). Compounds 3, 9, and 10 are new alkaloids. All compounds were tested for anti‐HBV activity against the 2.2.15 cell line in vitro. Dehydrocavidine (1), dehydroapocavidine (2), and dehydroisoapocavidine (3) exhibited inhibitory activity against HBsAg and HBeAg, but no cytotoxicity against the 2.2.15 cell line.
New Polyphenolic β‐Lactams with Antioxidant Activity
Authors: Cainelli Gianfranco , Angeloni Cristina , Cervellati Rinaldo , Galletti Paola , Giacomini Daria , Hrelia Silvana , Sinisi Riccardo 
Published: May 2008

AbstractNovel 4‐alkylidene‐β‐lactams with a polyphenolic side chain were synthesized and evaluated as radical scavengers. We have undertaken a detailed study of the antioxidant activity in vitro with chemical and biological testing of the new β‐lactams and of the corresponding methyl polyhydroxy benzoates. Antioxidant activity of β‐lactams and methyl benzoates was measured with the Briggs–Rauscher oscillating reaction, the TEAC (Trolox® Equivalent Antioxidant Capacity) assay, and as ability to inhibit ROS (=Reactive Oxygen Species) production on myoblast H9c2 cells. The results were discussed with regard to mechanism and correlated with structural parameters.
Microwave‐Assisted Synthesis of 4′‐Azaflavones and Their N‐Alkyl Derivatives with Biological Activities
Authors: Yaşar Ahmet , Akpınar Kurtuluş , Burnaz Nesibe Arslan , Küçük Murat , Karaoğlu Şengül Alpay , Doğan Neşe , Yaylı Nurettin 
Published: May 2008

Abstract4′‐Azaflavone (=2‐(pyridin‐4‐yl)‐4H‐1‐benzopyran‐4‐one; 4) and 3‐[(pyridin‐4‐yl)methyl]‐4′‐azaflavone (5) were synthesized by a simple environmentally friendly microwave‐assisted one‐pot method through the cyclization of 3‐hydroxy‐1‐(2‐hydroxyphenyl)‐3‐(pyridin‐4‐yl)propan‐1‐one (1), (E)‐2′‐hydroxy‐4‐azachalcone (2; chalcone=1,3‐diphenylprop‐2‐en‐1‐one), and 2′‐hydroxy‐2‐[(hydroxy)(pyridin‐4‐yl)methyl]‐4″‐azachalcone (3) under solventless conditions using silica‐supported NaHSO4, followed by treatment with base. In addition, N‐alkyl‐substituted 4′‐azaflavonium bromides 6 and 7 were prepared from compounds 4 and 5, respectively. The antimicrobial and antioxidant activities of compounds 1–7 were tested. The N‐alkyl‐substituted 4′‐azaflavonium bromides 6 and 7 showed high antimicrobial activity against the Gram‐positive bacteria and the fungus tested, with MIC values close to those of reference antimicrobials ampicilline and fluconazole. The alkylated compounds 6 and 7 also showed a good antioxidant character in the two antioxidant methods, DPPH (=1,1‐diphenyl‐2‐picrylhydrazyl) radical‐scavenging and ferric reducing/antioxidant power (FRAP) tests.
Synthesis and Characterization of Chiral Benzylic Ether‐Bridged Periodic Mesoporous Organosilicas
Authors: Morell Jürgen , Chatterjee Sangam , Klar Peter J. , Mauder Daniel , Shenderovich Ilja , Hoffmann Frank , Fröba Michael 
Published: May 2008

AbstractThe first synthesis of a chiral periodic mesoporous organosilica (PMO) carrying benzylic ether bridging groups is reported. By hydrolysis and condensation of the new designed chiral organosilica precursor 1,4‐bis(triethoxysilyl)‐2‐(1‐methoxyethyl)benzene (BTEMEB) in the presence of the non‐ionic oligomeric surfactant Brij 76 as supramolecular structure‐directing agent under acidic conditions, an ordered mesoporous chiral benzylic ether‐bridged hybrid material with a high specific surface area was obtained. The chiral PMO precursor was synthesized in a four‐step reaction from 1,4‐dibromobenzene as the starting compound. The evidence for the presence of the chiral units in the organosilica precursor as well as inside the PMO material is provided by optical activity measurements.
Bis(guanidinate) Alkoxide Complexes of Lanthanides: Synthesis, Structures and Use in Immortal and Stereoselective Ring‐Opening Polymerization of Cyclic Esters
Authors: Ajellal Noureddine , Lyubov Dmitrii M. , Sinenkov Mikhail A. , Fukin Georgii K. , Cherkasov Anton V. , Thomas Christophe M. , Carpentier Jean‐François , Trifonov Alexander A. 
Published: May 2008

AbstractA series of new bis(guanidinate) alkoxide Group 3 metal complexes [Ln{(Me3Si)2NC(NiPr)2}2(OR)] (R=OtBu, Ln=Y, Nd, Sm, Lu; R=OiPr, Ln=Y, Nd, Lu) has been synthesized. X‐ray structural determinations revealed that bis(guanidinate) tert‐butoxides are monomeric complexes. The isopropoxide complex [Y{(Me3Si)2NC(NiPr)2}2(OiPr)] undergoes slow decomposition in solution, to afford the unusual dimeric amido complex [(Y{(Me3Si)2NC(NiPr)2}2{μ‐N(iPr)CN})2]. Complexes [Ln{(Me3Si)2NC(NiPr)2}2(OR)] (R=OtBu, Ln=Y, Nd, Sm, Lu; R=OiPr, Ln=Y, Nd, Lu) are active catalysts/initiators for the ROP of rac‐lactide and rac‐β‐butyrolactone under mild conditions. Most of those polymerizations proceed with a significant degree of control. Bis(guanidinate) alkoxides appear to be well suited for achieving immortal polymerization of lactide, through the introduction of large amounts of isopropanol as a chain‐transfer agent. The synthesized complexes are able to promote the stereoselective ROP of rac‐β‐butyrolactone to afford syndiotactic poly(hydrobutyrate) through a chain‐end control mechanism, while they are surprisingly non‐stereoselective for the ROP of lactide under strictly similar conditions.
Supramolecular Sensing with Phosphonate Cavitands
Authors: Melegari Monica , Suman Michele , Pirondini Laura , Moiani Davide , Massera Chiara , Ugozzoli Franco , Kalenius Elina , Vainiotalo Pirjo , Mulatier Jean‐Christophe , Dutasta Jean‐Pierre , Dalcanale Enrico 
Published: May 2008

AbstractPhosphonate cavitands are an emerging class of synthetic receptors for supramolecular sensing. The molecular recognition properties of the third‐generation tetraphosphonate cavitands toward alcohols and water at the gas–solid interface have been evaluated by means of three complementary techniques and compared to those of the parent mono‐ and diphosphonate cavitands. The combined use of ESI‐MS and X‐ray crystallography defined precisely the host–guest association at the interface in terms of type, number, strength, and geometry of interactions. Quartz crystal microbalance (QCM) measurements then validated the predictive value of such information for sensing applications. The importance of energetically equivalent multiple interactions on sensor selectivity and sensitivity has been demonstrated by comparing the molecular recognition properties of tetraphosphonate cavitands with those of their mono‐ and diphosphonate counterparts.
Intraflagellar transport and the sensory outer segment of vertebrate photoreceptors
Authors: Insinna Christine , Besharse Joseph C. 
Published: May 2008

AbstractAnalysis of the other segments of rod and cone photoreceptors in vertebrates has provided a rich molecular understanding of how light absorbed by a visual pigment can result in changes in membrane polarity that regulate neurotransmitter release. These events are carried out by a large group of phototransduction proteins that are enriched in the outer segment. However, the mechanisms by which phototransduction proteins are sequestered in the outer segment are not well defined. Insight into those mechanisms has recently emerged from the findings that outer segments arise from the plasma membrane of a sensory cilium, and that intraflagellar transport (IFT), which is necessary for assembly of many types of cilia and flagella, plays a crucial role. Here we review the general features of outer segment assembly that may be common to most sensory cilia as well those that may be unique to the outer segment. Those features illustrate how further analysis of photoreceptor IFT may provide insight into both IFT cargo and the role of alternative IFT kinesins. Developmental Dynamics 237:1982–1992, 2008. © 2008 Wiley‐Liss, Inc.
Expression of the semaphorins Sema 3D and Sema 3F in the developing parathyroid and thymus
Authors: Takahashi Kaoru , Ishida Mami , Hirokawa Katsuiku , Takahashi Hiroshi 
Published: May 2008

AbstractWe have identified two Semaphorin genes, Sema 3D and Sema 3F, as being specifically expressed in the developing parathyroid and thymus. The thymus and parathyroid originate from a common primordium that develops from the third pharyngeal pouch in mice. The expression of Sema 3D and Sema 3F was compared with that of gcm2, Pax1, and Neuropilin‐1 and ‐2, and genes encoding a variety of Plexins by in situ hybridization during mouse pharyngeal development. Sema 3D was specifically expressed in the dorsal and cranial portions of the primordium developing from the third pouch at mouse embryonic day (E) 10.5. That the expression pattern of Sema 3D was consistent with that of gcm2 indicates that Sema 3D was expressed in the parathyroid‐specific domains of the developing third pouch. The parathyroid‐specific pattern of Sema 3D expression continued until E17.5. By contrast, Sema 3F was expressed in both the parathyroid and thymic domains of the common primordium at E10.5, and the expression levels in both tissues were decreased during development. The Semaphorin receptors were expressed in the blood vessels, nerves, and mesenchymal cells adjacent to the common primordium or the separated parathyroid and thymus during development. Our results show that Sema 3D and Sema 3F genes were overlappingly and distinctly expressed in the developing parathyroid and thymus, respectively, and that Semaphorin signaling might play roles in the interactions between these organs and surrounding tissues such as nerves and blood vessels, and in the recruitment of lymphoid cells. Developmental Dynamics 237:1699–1708, 2008. © 2008 Wiley‐Liss, Inc.
The germ plasm component vasa allows tracing of the interstitial stem cells in the cnidarian Hydractinia echinata
Authors: Rebscher Nicole , Volk C. , Teo R. , Plickert G. 
Published: May 2008

AbstractGerm cells in hydrozoans arise lifelong from multipotent interstitial stem cells. To discover if a true germline‐soma segregation exists in these species, we studied gametogenesis in Hydractinia echinata using in situ hybridization and immunohistochemistry for the germ cell marker Vasa. We could show that Hevas is a zygotic transcript, present in embryos from the gastrula stage onward. In the planula larva, Hevas is expressed in the interstitial stem cells located in the endoderm. During metamorphosis, Hevas‐expressing cells appear in the ectoderm in the lower half of the polyp. While the Hevas transcript is not detectable in developing gametes, the protein accumulates during oogenesis. Vasa containing granules are detectable at the polar‐body‐forming pole after fertilization. These results suggest that, in Hydractinia, maternal Vasa protein, but not the mRNA, is a maternal constituent of a germ plasm and might be involved in the specification and maintenance of interstitial stem cells. Developmental Dynamics 237:1736–1745, 2008. © 2008 Wiley‐Liss, Inc.
Investigation of Frizzled‐5 during embryonic neural development in mouse
Authors: Burns Carole J. , Zhang Jianmin , Brown Erinn C. , Van Bibber Alyssa M. , Van Es Johan , Clevers Hans , Ishikawa Tomo‐o , Taketo M. Mark , Vetter Monica L. , Fuhrmann Sabine 
Published: May 2008

AbstractRecent studies revealed that the Wnt receptor Frizzled‐5 (Fzd5) is required for eye and retina development in zebrafish and Xenopus, however, its role during mammalian eye development is unknown. In the mouse embryo, Fzd5 is prominently expressed in the pituitary, distal optic vesicle, and optic stalk, then later in the progenitor zone of the developing retina. To elucidate the role of Fzd5 during eye development, we analyzed embryos with a germline disruption of the Fzd5 gene at E10.25, just before embryos die due to defects in yolk sac angiogenesis. We observed severe defects in optic cup morphogenesis and lens development. However, in embryos with conditional inactivation of Fzd5 using Six3‐Cre, we observed no obvious early eye defects. Analysis of Axin2 mRNA expression and TCF/LEF‐responsive reporter activation demonstrate that Fzd5 does not regulate the Wnt/β‐catenin pathway in the eye. Thus, the function of Fzd5 during eye development appears to be species‐dependent. Developmental Dynamics 237:1614–1626, 2008. © 2008 Wiley‐Liss, Inc.
Phonological and orthographic spelling in high‐functioning adult dyslexics
Authors: Kemp Nenagh , Parrila Rauno K. , Kirby John R. 
Published: May 2008

AbstractDespite a history of reading or spelling difficulties, some adults attain age‐appropriate spelling skills and succeed at university. We compared the spelling of 29 such high‐functioning dyslexics with that of 28 typical students, matched on general spelling ability, and controlling for vocabulary and non‐verbal intelligence. Participants wrote derived real and pseudo words, whose spelling relationship to their base forms was categorized as phonologically simple (apt‐aptly), orthographically simple (deceit‐deceitful), phonologically complex (ash‐ashen), or orthographically complex (plenty‐plentiful). Dyslexic participants spelled all word and pseudoword categories more poorly than controls. Both groups spelled simple phonological words best. Dyslexics were particularly poor at spelling simple orthographic words, whose letter patterns and rules must likely be memorized. In contrast, dyslexics wrote more plausible spellings of orthographic than phonological pseudowords, but this might be an artefact of their more variable spelling attempts. These results suggest that high‐functioning dyslexics make some use of phonological skills to spell familiar words, but they have difficulty in memorizing orthographic patterns, which makes it difficult to spell unfamiliar words consistently in the absence of sufficient phonological cues or orthographic rules. Copyright © 2008 John Wiley & Sons, Ltd.
Selective activation, expansion, and monitoring of human iNKT cells with a monoclonal antibody specific for the TCR α‐chain CDR3 loop
Authors: Exley Mark A. , Hou Runhua , Shaulov Angela , Tonti Elena , Dellabona Paolo , Casorati Giulia , Akbari Omid , Akman H. Orhan , Greenfield Edward A. , Gumperz Jenny E. , Boyson Jonathan E. , Balk Steven P. , Wilson S. Brian 
Published: May 2008

AbstractA significant fraction of CD1d‐restricted T cells express an invariant T cell receptor (TCR) α‐chain. These highly conserved invariant NKT (iNKT) populations are important regulators of a wide spectrum of immune responses. The ability to directly identify and manipulate iNKT cells is essential to understanding their function and to exploit their therapeutic potential. To this end, we sought monoclonal and polyclonal antibodies specific for iNKT cells by immunizing CD1d KO mice, which lack iNKT cells, with a cyclic peptide modeled after the TCRα CDR3 loop. One mAb (6B11) was specific for cloned and primary human but not rodent iNKT cells and the human invariant TCRα, as shown by transfection and reactivity with human invariant TCRα transgenic T cells ex vivo and in situ. 6B11 was utilized to identify, purify, and expand iNKT cells from an otherwise minor component of human peripheral blood lymphocytes and to specifically identify human iNKT cells in tissue. Thus, we report a novel and general strategy for the generation of mAb specific for the CDR3 loop encoded by the TCR of interest. Specifically, an anti‐Vα24Jα18 CDR3 loop clonotypic TCR mAb is available for the enumeration and therapeutic manipulation of human and non‐human primate iNKT populations.
IL‐15 acts as a potent inducer of CD4+CD25hi cells expressing FOXP3
Authors: Imamichi Hiromi , Sereti Irini , Lane H. Clifford 
Published: May 2008

AbstractIL‐15 is a member of the γ chain‐dependent cytokines and known to affect innate and CD8+ adaptive immune responses. Despite a growing interest in the use of IL‐15 as an immunotherapeutic agent, the broad spectrum of immunoregulatory functions exerted by IL‐15 has not been fully elucidated. Here, we demonstrate that IL‐15 increases expression of CD25 and forkhead box transcription factor P3 (FOXP3), a master transcriptional regulator of regulatory T cells, in human peripheral CD4+CD25– T cells in the absence of antigenic stimulation. Comparisons involving IL‐2 and IL‐7 revealed that the induction of CD25hi and FOXP3 expression was most prominent with IL‐15 and IL‐2. More modest effects were seen with IL‐7. Despite levels of FOXP3 expression comparable to that of conventional regulatory T cells, cytokine‐induced CD4+CD25hiFOXP3+ cells exerted only weak suppressor activity. Thus, the current study has demonstrated that IL‐15 acts as a potent inducer of CD4+CD25hiFOXP3+ cells in the periphery, and suggests a potential role for IL‐15 in blunting immune activation. This study has provided further insights into the pleiotropic nature of IL‐15 beyond the regulation of CD8+ T cells.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/37607_s.pdf
DNA methylation controls Foxp3 gene expression
Authors: Polansky Julia K. , Kretschmer Karsten , Freyer Jennifer , Floess Stefan , Garbe Annette , Baron Udo , Olek Sven , Hamann Alf , von Boehmer Harald , Huehn Jochen 
Published: May 2008

AbstractCompelling evidence suggests that Foxp3‐expressing CD25+CD4+ regulatory T cells (Treg) are generated within the thymus as a separate lineage. However, Foxp3+CD4+ Treg can also be generated de novo in a TGF‐β‐dependent process from naive T cells by TCR triggering. Recently, we have shown that naturally occurring, but not in vitro TGF‐β‐induced Foxp3+ Treg display stable Foxp3 expression that was associated with selective demethylation of an evolutionarily conserved element within the Foxp3 locus named TSDR (Treg‐specific demethylated region). Here, we report that inhibition of DNA methylation by azacytidine, even in absence of exogenous TGF‐β, not only promoted de novo induction of Foxp3 expression during priming, but also conferred stability of Foxp3 expression upon restimulation. Most notably, such stable Foxp3 expression was found only for cells displaying enhanced TSDR demethylation. In contrast, in vitro TSDR methylation diminished its transcriptional activity. Foxp3+ Treg generated in vivo by DEC‐205‐mediated targeting of agonist ligands to dendritic cells showed long‐term survival in the absence of the inducing antigen and exhibited efficient TSDR demethylation. Together, our data suggest that TSDR is an important methylation‐sensitive element regulating Foxp3 expression and demonstrate that epigenetic imprinting in this region is critical for establishment of a stable Treg lineage.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/38105_s.pdf
Lamina propria dendritic cells: For whom the bell TOLLs?
Authors: Rescigno Maria , Matteoli Gianluca 
Published: May 2008

AbstractOne of the major tasks of the mucosal immune system is to discriminate between dangerous and harmless antigens that are encountered daily at mucosal sites. In the gastrointestinal tract, immune cells have to tolerate food antigens and commensal microbes but at the same time have to induce a prompt response against invasive pathogens, when needed. In this issue of the European Journal of Immunology, it is shown that intestinal dendritic cell (DC) populations can be distinguished based on the expression level of Toll‐like receptors (TLR) and on the response of these TLR to their microbial ligands. DC either do not express TLR or they express them but respond in a non‐inflammatory mode. In this commentary, these findings are discussed in the context of available knowledge on lamina propria DC.See accompanying article http://dx.doi.org/10.1002/eji.200737909
Synthesis and Reactivity of Monocyclopentadienyltantalum(V) Siloxide Complexes
Authors: Conde Ana , Fandos Rosa , Otero Antonio , Rodríguez Ana , Terreros Pilar 
Published: May 2008

AbstractThe new tantalum siloxide complex [TaCp*Me3(OSiPh3)] (1; Cp* = η5‐C5Me5) has been synthesized. The reaction of complex 1 with isocyanides yields the respective azatantalacyclopropanes [TaCp*(η2‐Me2CNxylyl)Me(OSiPh3)] (2; xylyl = 2,6‐dimethylphenyl) and [TaCp*(η2‐Me2CNtBu)Me(OSiPh3)] (3). The molecular structure of complex 2 has been established by X‐ray diffraction. Complex 2 reacts with a second mol‐equiv. of 2,6‐xylyl isocyanide to yield [TaCp*(Nxylyl)[N(xylyl)CMe=CMe2)(OSiPh3)] (4). The reaction of 1 with carbon monoxide gives [TaCp*(O)(OCMe=CMe2)(OSiPh3)] (5), whereas 1 reacts with B(C6F5)3 to give the corresponding cationic compound [TaCp*Me2(OSiPh3)][MeB(C6F5)3] (6). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Self‐Assembled Azaphthalocyanine Dimers with Higher Fluorescence and Singlet Oxygen Quantum Yields than the Corresponding Monomers
Authors: Novakova Veronika , Zimcik Petr , Kopecky Kamil , Miletin Miroslav , Kuneš Jiří , Lang Kamil 
Published: May 2008

AbstractIn this work, we describe diethylamino‐substituted metalazaphthalocyanines that form self‐assembled J‐dimers in noncoordinating solvents. The dimers are formed by the coordination of the free electron pair of one diethylamino group with the central metal of the adjacent molecule. The addition of pyridine leads to monomerization and considerable quenching of fluorescence and singlet oxygen formation as a result of intramolecular photoinduced singlet electron transfer (PET). PET is efficiently inhibited in dimers; therefore, dimers have higher fluorescence and singlet oxygen quantum yields than the corresponding monomers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemiluminescence of Tris(2,2′‐bipyridine)ruthenium with Various Co‐reactants under Ultrasound Irradiation
Authors: Takahashi Fumiki , Jin Jiye 
Published: May 2008

AbstractElectrochemiluminescence (ECL) of tris(2,2′‐bipyridine)ruthenium, Ru(bpy)32+ in the presence of various co‐reactants, such as tripropylamine (TPA), oxalate ion (C2O42−), ascorbic acid (H2A) and dehydroascorbic acid (DHA), were investigated under ultrasound irradiation. In sono‐ECL experiments, an indium‐thin‐oxide (ITO) was used as working electrode, and a titanium tipped sonic horn probe (diameter 2 mm) which operated at a frequency of 20 kHz was set in the front of the ITO electrode. Under the ultrasound irradiation, ECL signals were found to be significantly enhanced when TPA and C2O42− were used as co‐reactants, only slightly enhanced in Ru(bpy)32+/DHA system, but total quenched in Ru(bpy)32+/H2A system. The difference of Ru(bpy)32+ ECL behaviors for various co‐reactant could to be due to the different kinetics of catalytic reactions associated in ECL schemes. ECL quenching effect observed in Ru(bpy)32+/H2A system was suggested to be due to electron transfer (ET) route between the excited state *Ru(bpy)32+ and ascorbate anion HA− diffused from the bulk solution, where the diffusional HA− species served as electron donor. The effect becomes more pronounced upon sonication because the effective collision frequency between *Ru(bpy)32+ and HA− would be significantly increased by the enhanced mass transport effect of ultrasound.