bluuebunny/crossref_metadata_2025_split huggingface dataset:
7‐Substituted‐[1, 4]dioxano[2, 3‐g]quinazolines as Inhibitors of Epidermal Growth Factor Receptor Kinase
Authors: Lee Jae Yeol , Park Yong Kyu , Seo Seon Hee , Yang Beom‐Seok , Park Hokoon , Lee Yong Sup 
Published: December 2002

AbstractWith the aim of developing inhibitors of EGFR tyrosine kinase, the 7‐methoxymethyl‐[1, 4]dioxano[2, 3‐g]quinazolines (3a—b) and 7‐mono‐ or di‐alkylaminomethyl‐[1, 4]dioxano[2, 3‐g]quinazolines (4a—i) were prepared and evaluated for the inhibition of EGFR tyrosine kinase and the growth inhibition of human tumor cell lines. Among them, compounds 4d and 4h showed potencies against both EGFR tyrosine and the A431 cell line similar to that of PD153035 with greater aqueous solubilities of their HCl salts.
Naphthalene‐1,8‐diyl Bis(Halogenophosphanes): Novel Syntheses and Structures of Useful Synthetic Building Blocks
Authors: Kilian Petr , Slawin Alexandra M. Z. , Woollins J. Derek 
Published: December 2002

AbstractA series of new bay region disphospha‐functionalised naphthalenes is reported. The reduction of ylidic phosphonium phosphoride NapP2Cl6 (1) (Nap=naphthalene‐1,8‐diyl) with MeOPCl2 gives the important synthon Nap(PCl2)2 (2) in nearly quantitative yield. Reaction of 1 with magnesium metal affords (NapP2)n (3), which reacts with Br2 and I2, yielding Nap(PBr2)2 (4) and Nap(PI)2 (5), respectively. X‐ray structure determinations reveal a twisted geometry of the naphthalene ring in sterically strained 2 and 4, whilst the presence of a PP bond in 5 results in the release of the steric strain and generation of the planar NapP2 moiety. Although the tetrahedral P environments are severely distorted the σ3Pσ3P bonding in 5 represents a new type of PP bonding environment in 1,8‐diphosphanaphthalenes. Compounds 1, 4 and 5 each represent the highest coordination, achievable by direct halogenation. The new compounds 2–5 were fully characterised by NMR, IR, and Raman spectroscopy, mass spectrometry, and elemental analysis.
Total Synthesis of Woodrosin I—Part 1: Preparation of the Building Blocks and Evaluation of the Glycosylation Strategy
Authors: Fürstner Alois , Jeanjean Fabien , Razon Patrick , Wirtz Conny , Mynott Richard 
Published: December 2002

AbstractThe preparation of three building blocks required for the total synthesis of woodrosin I (1) is outlined, a complex resin glycoside bearing a macrolide ring which spans four of the five sugars of its oligosaccharide backbone. Key steps involve the enantioselective, titanium‐catalyzed addition of dipentylzinc to 5‐hexenal, the glycosylation of the resulting alcohol 18 with the glucose‐derived trichloroacetimidate 7, and further elaboration of the resulting product 19 into disaccharide 22 on treatment with the orthogonally protected glycosyl donor 15. The trichloroacetimidate method is also used for the formation of the second synthon represented by disaccharide 38. A model study shows that the assembly of the pentasaccharidic perimeter of 1 depends critically on the phasing of the glycosylation events between fragments 22, 38 and the rhamnosyl donor 27 due to the severe steric hindrance in the product. A particularly noteworthy finding is the fact that diol 22 can be regioselectively glycosylated at the 3′‐OH group in high yield without protection of the neighboring 2′‐OH function.
Total Synthesis of Woodrosin I—Part 2: Final Stages Involving RCM and an Orthoester Rearrangement
Authors: Fürstner Alois , Jeanjean Fabien , Razon Patrick , Wirtz Conny , Mynott Richard 
Published: December 2002

AbstractThe completion of the first total synthesis of the complex resin glycoside woodrosin I (1) is outlined using the building blocks described in the preceding paper. Key steps involve the TMSOTf‐catalyzed coupling of diol 2 with trichloroacetimidate 3 which leads to the selective formation of orthoester 5 rather than to the expected tetrasaccharide. Diene 5, on treatment with catalytic amounts of the Grubbs carbene complex 6 or the phenylindenylidene ruthenium complex 7, undergoes a high yielding ring closing olefin metathesis reaction (RCM) to afford macrolide 8. Exposure of the latter to the rhamnosyl donor 4 in the presence of TMSOTf under “inverse glycosylation” conditions delivers compound 9 by a process involving glycosylation of the sterically hindered 2′‐OH group and concomitant rearrangement of the adjacent orthoester into the desired β‐glycoside. This transformation constitutes one of the most advanced applications of the Kochetkov glycosidation method reported to date. Cleavage of the chloroacetate followed by exhaustive hydrogenation completes the total synthesis of the targeted glycolipid 1.
Gas‐Phase Chemistry of Ethynylamine, ‐Phosphine and ‐Arsine. Structure and Stability of their Cu+and Ni+Complexes
Authors: Galiano Luis , Alcamí Manuel , Mó Otilia , Yáñez Manuel 
Published: December 2002

AbstractThe Cu+and Ni+binding energies of ethynylamine, ethynylphosphine and ethynylarsine have been calculated at the B3LYP/6‐311+G(2df,2p)//B3LYP/6‐311G(d,p) level of theory. Significant differences between nitrogen‐containing and phosphorus‐ or arsenic‐containing compounds have been found regarding structural effects upon metal cation association. While for ethynylamine the global minimum of the potential energy surface corresponds to the complex in which the metal cation binds to theβ‐carbon, for ethynylphosphine the most favourable process corresponds to phosphorus attachment. For ethynylarsine, the conventionalπ‐complex is the most stable one. This behavior resembles that found for the corresponding vinyl analogues, with the only exception being the arsenic derivative. The calculated Cu+and Ni+binding energies for attachment to the heteroatom follow a different trend, P>As>N, to that predicted for the corresponding proton affinities, P>N>As. Cu+and Ni+binding energies are almost identical when the metal cation binds to the heteroatom. However, Ni+binding energies are slightly larger than Cu+binding energies when the metal cation interacts with the CC bond.
Pseudopeptide Foldamers − The Homo‐Oligomers of Benzyl (4S,5R)‐5‐Methyl‐2‐oxo‐1,3‐oxazolidine‐4‐carboxylate
Authors: Tomasini Claudia , Trigari Valerio , Lucarini Simone , Bernardi Fernando , Garavelli Marco , Peggion Cristina , Formaggio Fernando , Toniolo Claudio 
Published: December 2002

AbstractA 2‐oxo‐1,3‐oxazolidine‐4‐carboxylic acid was designed as a new, conformationally restricted building block for the construction of pseudopeptide foldamers. IR, 1H NMR and CD techniques, implemented by detailed DFT computational modeling, were exploited to investigate the preferred three‐dimensional structure of benzyl (4S,5R)‐5‐methyl‐2‐oxo‐1,3‐oxazolidine‐4‐carboxylate homo‐oligomers synthesized to the pentamer level. The resulting poly(L‐Pro)n II like helical conformation was found to be stabilized by intramolecular α‐C−H···O=C hydrogen bonds. This novel, acylurethane‐based, ternary foldameric structure, if appropriately functionalized, holds promise as a robust template for a variety of applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Asymmetric Synthesis of (S)‐4‐Oxopipecolic Acid by a 3+3 Atom‐Unit Assembly Strategy
Authors: Partogyan‐Halim Karolin , Besson Laure , Aitken David J. , Husson Henri‐Philippe 
Published: December 2002

Abstract(S)‐4‐Oxopipecolic acid has been prepared in enantiomerically pure form from two readily accessible starting materials, (R)‐N‐(cyanomethyl)‐4‐phenyloxazolidine (2) and 2‐(methoxymethoxy)allyl chloride, (3, MOM‐allyl chloride). This strategy exploits the complementary electrophile/nucleophile reactivity at each end of this pair of 3‐atom unit building blocks. Thus, alkylation of the anion of 2 with 3 (creation of the piperidine C‐2−C‐3 bond) followed by Lewis acid induced cyclisation (creation of the C‐5−C‐6 bond), leads principally to a bicyclic intermediate 5 which incorporates a protected form of the title compound. Subsequent chemical transformations lead to the target molecule in an overall yield of 20% for the five‐step sequence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Novel Approach to 2‐Chloro‐2‐fluorostyrenes
Authors: Nenajdenko Valentine G. , Shastin Alexey V. , Korotchenko Vasily N. , Varseev Georgy N. , Balenkova Elisabeth S. 
Published: December 2002

AbstractA new general catalytic olefination reaction (COR) of aromatic and heteroaromatic aldehydes and ketones was applied to synthesise 2‐chloro‐2‐fluorostyrenes. The two‐stage procedure includes the transformation of carbonyl compounds into hydrazones followed by treatment with CFCl3 mediated by copper catalysis. Trichlorofluoromethane was used as a chlorofluoromethylene transfer reagent. The reaction proceeds stereoselectively and the target alkenes were obtained in high yield. A proposed mechanism for the reaction is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Brominated Oxylipins and Oxylipin Glycosides from Red Sea Corals
Authors: Řezanka Tomáš , Dembitsky Valery M. 
Published: December 2002

AbstractEight new brominated oxylipins 1−8, including two glycosides, were isolated from the Red Sea invertebrates Dendrophyllia sp., Dendronephthya sp. (red variety), Dendronephthya sp. (yellow variety), and Tubipora musica. Their structures were elucidated mainly on the basis of NMR spectroscopic data. The relative and absolute configurations were determined by analysis of NOESY and CD data and by the modified Mosher method. The compounds gave positive results in a brine shrimp toxicity assay, a sea urchin eggs test (Paracentrotus lividus), and a crown gall tumor on potato disks test (Agrobacterium tumefaciens). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Isolation and Structural Determination of Four New Ceramide Lactosides from the Starfish Luidia maculata
Authors: Inagaki Masanori , Nakamura Kazufumi , Kawatake Satoshi , Higuchi Ryuichi 
Published: December 2002

AbstractFour new ceramide lactosides, luidialactoside A (1), B (3), C (4), and D (5) were isolated from the water‐insoluble lipid fraction of the CHCl3/MeOH extract of the starfish Luidia maculata. The structures of these ceramide lactosides were determined on the basis of chemical and spectroscopic evidence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Injection Moulding: Evaluation of Appropriate Melt Injection Points for the Gas Injection Technique
Authors: Heim Hans‐Peter 
Published: December 2002

AbstractIn gas assisted injection moulding the melt front advancement has a considerable effect on the gas penetration. The evaluation of an appropriate melt filling is an important step to avoid instabilities in the process sequence. Taking a sample moulded part a procedure is presented that enables the part designer to evaluate required melt and gas injection points according to the gas injection technique. Using finite element simulations, different calculations for the melt front advancement lead to the correct gate location.
Presentation of different degrees of filling for the optimised article geometry.magnified imagePresentation of different degrees of filling for the optimised article geometry.
Development of a Portable Online Rheometer for the Characterization of PVC Melts
Authors: Limper Andreas , Fattmann Gordon , Seibel Stefan 
Published: December 2002

AbstractPoly(vinyl chloride) (PVC) is a standard polymer with a world‐wide sales quantity of more than 20 Mio. t. From a rheological point of view, PVC is much more difficult to classify than for example polyethylene. Standard thermoplastics can be plasticized by the input of thermal energy, whereas for a sufficient plastification of PVC shear energy is needed. Hence, the PVC melt properties measured with the help of standard lab‐scale rheometers are not taking the shear history into account. Therefore, the melt behavior within an extruder cannot be described. In addition, PVC melts show wall slipping effects. A new rheometer concept especially developed to characterize PVC melt is presented. The rheometer takes a representative melt stream between the screw tip and the inflow of the die. The pressure gradient of this melt stream is measured within the geometry of the rheometer. Due to this the shear history and the wall slipping effects can be accounted for. Experimental data and results are presented and the application possibilities such as the design of profile dies and the development of PVC recipes are discussed.
The portable online rheometer in the assembled state.magnified imageThe portable online rheometer in the assembled state.
Scale‐Up in the Design of Extrusion Dies
Authors: Potente Helmut , Kramme Sandra 
Published: December 2002

AbstractThe similarity theory and the scale‐up procedure developed from it make it possible to convert a technical‐physical process from one scale to another – generally in the upwards direction. In the design of extrusion dies with an annular die gap, the die is broken down into basic geometric elements, and scale‐up rules are then drawn up for the individual elements. In this project, scale‐up rules were found that satisfy both full and partial similarity. The pseudoplasticity and elasticity of the melt were also taken into consideration. A comparison of the model laws obtained with the results of finite element calculations showed good conformity between the models and the production versions.
Deviation in pressure difference between the model and the production version assuming flow behavior in accordance with the power law (Di = const. and L = const.).magnified imageDeviation in pressure difference between the model and the production version assuming flow behavior in accordance with the power law (Di = const. and L = const.).
Analysis of the Influence of Rotor Design on the Stream Flow Conditions Within an Internal Mixer
Authors: Limper Andreas , Wilhelmsmeyer Tom 
Published: December 2002

AbstractA flow visualisation apparatus is described which allows to compare different rotor designs to each other. In order to observe the distributive mixing effect, the stream flow and dispersive mixing effect is monitored by an indirect measurement of the power impact within the material. Assuming that the mixing process of an internal mixer is not continuous, a testing device was build to the scale of a 90 l kneader. In this device the mixing chamber and the rotor blade are unwound into the flat plane. With this testing device it is possible to carry out a systematic analysis of the influence of rotor design on the flow processes within an internal mixer in a fast and inexpensive way.
The test device.magnified imageThe test device.
Compounding Unit Planetary Roller Extruder
Authors: Limper Andreas , Seibel Stefan , Fattmann Gordon 
Published: December 2002

AbstractPlanetary roller extruders (PREs) are currently being employed first and foremost to feed calender/lamination units, for pelleting, for compounding powdered paint and for the reuse of recyclate. In these disciplines it is the most successful multi‐screw extruder. The range of materials that are compounded extends from classical plasticised poly(vinyl chloride) (PVC), via poly(propylene) (PP) and acrylonitrile‐butadiene‐styrene (ABS), through to powdered rubber. The planetary roller extruders convince in comparison with other compounding machines through the thermally carefully compounding, the balanced ratio of shear and heat transfer and the narrow residence time distribution. Experimental investigations to analyze the process behavior of PREs were carried out for the first time.
Homogenization and dispersion at a material‐bank in the planetary roller extrusion test stand.magnified imageHomogenization and dispersion at a material‐bank in the planetary roller extrusion test stand.
Genetic mutation associated with meiotic metaphase‐specific apoptosis in MRL/MpJ mice
Authors: Namiki Yuka , Endoh Daiji , Kon Yasuhiro 
Published: December 2002

AbstractIt has been reported that the MRL/MpJ mouse strain shows several unique phenotypes, including rapid wound healing, inherent collagen disease, heat shock‐resistant spermatocytes, and metaphase‐specific apoptosis (Msa) in the testis. In the present study, we found the genetic mutation associated with Msa by chromosomal mapping with 555 backcross progeny. The Sertoli cell index of abnormal metaphasic spermatocytes was clearly divided into two groups in the first 200 male backcross progeny, which were created by mating female F1 (female C57BL/6 × male MRL/MpJ) with male MRL/MpJ mice, indicating that Msa was caused by only one gene. The result of chromosomal mapping throughout the 555 backcross progeny by using microsatellite markers and single nucleotide polymorphism (SNP) revealed that Msa was mapped on the telomeric region of chromosome 1 and was significantly linked with exonuclease 1 (Exo1) and choroideremia‐like (rab escort protein 2) (Chml/Rep2) genes. It was found that the Chml/Rep2 gene was not a candidate for Msa by means of the nucleotide sequences of several inbred strains. On the Exo1 gene in strain MRL/MpJ, but not in other strains, it was surprisingly noted that the truncated forms (tr1‐Exo1 and tr2‐Exo1) were expressed in all tissues examined as well as normal Exo1 by reverse transcriptase‐polymerase chain reaction (RT‐PCR). Additionally, the truncated forms of the Exo1 gene were suggested to be transcribed by alternative splicing of the 9th exon, possibly resulting from nucleotide substitution of the branch site existing in the 8th intron. These results suggested that the testicular meiotic Msa in MRL/MpJ mice was a unique phenotype caused by incomplete alternative splicing of the Exo1 gene. Mol. Reprod. Dev. 64: 179–188, 2003. © 2003 Wiley‐Liss, Inc.
Expression in Escherichia coli and immunological characterization of three zona pellucida proteins (ZP1, ZP2, and ZP3) from a marsupial, the brushtail possum (Trichosurus vulpecula)
Authors: Mate Karen E. , Buist Janine M. , Duckworth Janine A. 
Published: December 2002

AbstractThe brushtail possum (Trichosurus vulpecula) zona pellucida (ZP) is composed of three major glycoproteins, designated ZP1, ZP2, and ZP3 based on their size and homology with eutherian ZP proteins. These proteins are candidate antigens for the development of an immunocontraceptive vaccine to control the fertility of the brushtail possum in New Zealand, where it is an introduced pest. In order to further their immunological and functional characterization, recombinant possum ZP proteins were produced in Escherichia coli (E. coli) strain JM109, M15, SG13009, or BL21 codon plus. Each of the proteins produced possessed a N‐terminal six histidine tag (His)6 to facilitate purification and consisted of amino acid (aa) residues 18–471 of possum ZP1, aa residues 40–311 of ZP2 (ZP2‐N), aa residues 305–634 of ZP2 (ZP2‐C), and aa residues 23–342 of ZP3. Immunoblot using anti‐RGS(His)4 antibodies and polyclonal rabbit anti‐porcine ZP antibodies detected major bands at 54 kDa for ZP1, 32 kDa for ZP2‐N, 39 kDa for ZP2‐C, and 40 kDa for ZP3. Immunization of male and female rabbits with ZP2‐N, ZP2‐C, and ZP3 purified on Ni‐NTA resin under denaturing conditions generated antibodies reactive with recombinant ZP proteins on Western blot and with native ZP proteins in possum ovarian sections using immunofluorescence. Antibodies generated against ZP1 in the same way were reactive with recombinant ZP proteins on Western blot only. The recombinant possum ZP proteins and specific antibodies produced in this study give an indication of the antigenic relationship of the possum ZP proteins and are vital tools for future studies of sperm‐ZP binding in marsupials and for the evaluation of ZP‐based contraceptive vaccines in possums and other marsupials. Mol. Reprod. Dev. 64: 136–143, 2003. © 2003 Wiley‐Liss, Inc.
Isolation and partial characterization of three pregnancy‐associated glycoproteins from the ewe placenta
Authors: El Amiri Bouchra , Remy Benoit , Sousa Noelita Melo , Joris Bernard , Ottiers Nicole Gerardin , Perenyi Zsolt , Mboko Henri Banga , Beckers Jean‐Francois 
Published: December 2002

AbstractPregnancy‐associated glycoproteins (PAGs) are synthesized in the outer epithelial layer of the placenta in artiodactyls. In this work, three novel ovine PAGs were isolated from late‐pregnancy fetal cotyledons and characterized biochemically. The isolation procedure included acid and ammonium sulfate precipitations and anion and cation exchange chromatographies. The isolated PAGs have different NH2‐terminal amino acid sequences (RGSXLTILPLRNMRDIVY, ISRVSXLTIHPLRNIMDML, and RGSNLTIHPLRNIRD) and apparent molecular masses (55, 57, and 59 kDa). Each shows several isoforms with different pI values. The three proteins share high sequence identity with each other and with other ovine, bovine, and caprine PAGs. They have not been described previously. The ovPAG‐59 sequence differs from the previously identified ovPAG‐4 sequence (determined by DNA cloning and sequencing) at only one position among the 15 N‐terminal residues. The newly characterized ovPAGs and the procedure used to isolate them will be helpful in producing new antisera for investigating PAG secretion in pregnant ewes. Mol. Reprod. Dev. 64: 199–206, 2003. © 2003 Wiley‐Liss, Inc.
Classical cadherin and catenin expression in normal myometrial tissues and uterine leiomyomas
Authors: Tai Chin‐Tao , Lin Wu‐Chou , Chang Wei‐Chun , Chiu Tsan‐Hung , Chen George T.C. 
Published: December 2002

AbstractUterine leiomyomas are the most common benign uterine tumors in the women of reproductive age. Previous studies have suggested that uterine leiomyomas are monoclonal tumors derived from a single neoplastic myometrial cell. However, the neoplastic transformation of myometrium to leiomyomas remains to be elucidated. The classical cadherins are a gene family of integral membrane glycoproteins that mediate calcium‐dependent cell–cell adhesion in a homophilic manner. These cell adhesion molecules (CAMs) have been shown to play pivotal roles in tumorigenesis. Catenins are intracellular proteins that link the cytoplasmic domains of the cadherins to the cytoskeletons to promote the biological functions of these CAMs. In this study, we compared the expression of E‐, N‐, and P‐cadherins and α‐, β‐, and γ‐catenins in the uterine leiomyomas and the counterparts of normal myometrium of the same patients by using semiquantitative reverse transcription‐polymerase chain reaction (RT‐PCR) and Western blot analysis. Of these, E‐cadherin (E‐cad) was not detected in both uterine leiomyomas and myometrium, P‐cadherin (P‐cad) was similarly expressed in these two tissues, but N‐cadherin (N‐cad) mRNA and protein expression levels in uterine leiomyomas were significantly greater than those observed in the myometrium. Catenins were not differentially expressed in uterine myometrium and leiomyomas. The overexpression of N‐cad in uterine leiomyomas suggests that this CAM may play a central role in the development of uterine leiomyomas. Mol. Reprod. Dev. 64: 172–178, 2003. © 2003 Wiley‐Liss, Inc.
Raman spectroscopy of heavily doped polycrystalline and microcrystalline silicon
Authors: Lengsfeld P. , Brehme S. , Brendel K. , Genzel Ch. , Nickel N. H. 
Published: December 2002

AbstractRaman measurements of heavily doped laser crystallized poly‐Si and as‐deposited μc‐SH show significant differences between the two materials. Poly‐Si samples exhibit the Fano effect just like heavily doped c‐Si samples. This is not true for the heavily doped μc‐SH samples.