bluuebunny/crossref_metadata_2025_split huggingface dataset:
First 13C‐NMR Assignments of Betaxanthins
Authors: Stintzing Florian C. , Kugler Florian , Carle Reinhold , Conrad Jürgen 
Published: May 2006

AbstractDue to their inherent liability towards highly acidic conditions previously considered to be a prerequisite for data acquisition, betaxanthin structure dereplication by NMR spectroscopy has been scarcely reported and was, hitherto, exclusively based on 1H‐NMR data interpretation. Applying only slightly acidic conditions, we herein report the first 13C‐NMR data of two betaxanthins, i.e., indicaxanthin (1), isolated from yellow‐orange cactus pear fruits (Opuntia ficus‐indica [L.] Mill. cv. ‘Gialla’), and of miraxanthin V (2) from yellow Swiss chard petioles (Beta vulgaris L. ssp. cicla [L.] Alef. cv. ‘Bright Lights’), as derived by gHSQC‐ and gHMQC‐NMR experiments and inverse detection.
A New 18(13 → 12β)‐abeo‐Lanostadiene Triterpenoid from Ganoderma fornicatum
Authors: Qiao Ying , Zhang Xian‐Min , Dong Xue‐Chang , Qiu Ming‐Hua 
Published: May 2006

AbstractA new triterpenoid, fornicatin C (= (3β)‐3‐hydroxy‐18(13 → 12β)‐abeo‐lanosta‐13(17),24‐dien‐18‐oic acid; 1), was isolated from the fruiting bodies of Ganoderma fornicatum, together with the known compounds fornicatin A (2) and fornicatin B (3), among other constituents. The structure of 1 was elucidated by means of spectroscopic techniques, and those of 2 and 3 were identified by comparing their spectroscopic data with those reported in the literature.
Effect of the Secondary Reduction on the Enantioselectivity and Function of Additives in the Chiral Oxazaborolidine‐Catalyzed Asymmetric Borane Reduction of Ketones
Authors: Liu Han , Du Da‐Ming , Xu Jiaxi 
Published: May 2006

AbstractThe secondary reduction in the direct and oxazaborolidine‐catalyzed asymmetric borane reduction of ketones was investigated by the use of GC/MS tracing titration and control experiments. The results indicate that the secondary reduction affects the enantioselectivity only in noncoordinated solvents at low temperature and not under the usual catalytic reduction conditions because the intermediate alkoxyborane is unstable and quickly converts to borane and dialkoxyborane. The function of an alcohol additive in the asymmetric borane reduction of ketones is to consume excess borane in the reduction system thus inhibiting noncatalytic reduction, which leads to increased enantioselectivity in the catalytic reduction.
Radio‐Analytical Determination of the Coating Efficiency of Cyclic RGD Peptides
Authors: Auernheimer Jörg , Haubner Roland , Schottelius Margret , Wester Hans‐Jürgen , Kessler Horst 
Published: May 2006

AbstractCoating of artificial surfaces with RGD (= arginine‐glycine‐aspartate) peptides to enhance cell adhesion is an ongoing issue. Thereby, the physiological adhesion process to the extra‐cellular matrix (ECM) is mimicked by the peptide coating, leading to a strong cell‐surface contact, followed by spreading and proliferation of the cells. For comparable cell adhesion studies, it is important to know the density of the RGD peptides on the surface. Here, we present an approach to determine the amount of bound cyclic RGD peptide by radio labeling with 125I of a tyrosine‐containing RGD peptide on different materials surfaces (poly(methyl methacrylate) (PMMA), titanium, and silicon). For all surfaces, the amount of bound peptides is in the range of pmol/cm1.
A Minimalist Approach to CH Activation by Copper
Authors: Kuebel‐Pollak Anita , Rüttimann Stéphane , Dunn Nichola , Melich Xavier , Williams Alan F. , Bernardinelli Gérald 
Published: May 2006

AbstractThe complex [Cu2(1)2]2+ (1 = 1,3‐bis(1‐methyl‐1H‐benzimidazol‐2‐yl)benzene) undergoes slow oxidation by dioxygen in DMF solution to give the hydroxylated product [Cu2(2‐H)2]2+ (2 = 2,6‐bis(1‐methyl‐1H‐benzimidazol‐2‐yl)phenol) characterized by an X‐ray crystal‐structure analysis. The oxidation occurs much faster when CuII is mixed with 1 in the presence of H2O2, with 80% hydroxylation observed within a few minutes. The mononuclear complex formed with 1‐methyl‐2‐phenyl‐1H‐benzimidazole (3) shows no hydroxylation under these conditions. It is concluded that the hydroxylation requires the presence of a ligand capable of stabilizing a binuclear species, but no special coordinative activation of the copper is required.
Palladium‐Catalyzed 2‐Phenylethenylation of Codeine: 8‐[(1E)‐2‐Phenylethenyl]codeinone Dimethyl Ketal as the Unexpected ‘Masked’ Diene for the Preparation of 19‐Substituted Diels–Alder Adducts of Thebaine
Authors: Kalinin Valery N. , Shishkov Igor V. , Moiseev Sergey K. , Shults Elvira E. , Tolstikov Genrikh A. , Sosnina Natalia I. , Petrovskii Pavel V. , Lyssenko Konstantin A. , Schmidhammer Helmut 
Published: May 2006

AbstractIn a search for starting materials for the preparation of 7,8‐fused morphine alkaloid derivatives, 8‐[(1E‐2‐phenylethenyl]codeinone dimethyl ketal (4) and 8‐[(1E‐2‐phenylethenyl]codeine (5) were prepared. These dienes were used as substrates in the Diels–Alder reactions. Compound 5 formed the ‘normal’ adduct 12 with N‐phenylmaleimide, while compound 4 behaved in reactions with dienophiles as the ‘masked’ diene 11, a 8‐[(1E)‐2‐phenylethenyl]‐substituted thebaine, yielding the corresponding 19‐substituted 6,14‐endo‐etheno‐6,7,8,14‐tetrahydrothebaines. Specifically, reaction of 4 with methyl vinyl ketone gave rise to 19‐[(1E)‐phenylethenyl]thevinone (14) whose structure was elucidated by an X‐ray diffraction analysis. The thebaine derivative 11 was also prepared from 4.
Sesquiterpenoids and Lignans from Ligularia virgaurea spp. oligocephala
Authors: Li Ya , Shi Yan‐Ping 
Published: May 2006

AbstractFrom the BuOH extract of the whole plant of Ligularia virgaurea spp. oligocephala, a series of sesquiterpenes, sesquiterpene glycosides, and lignan glycosides were isolated, including the three new compounds (1α)‐1‐hydroxy‐8‐oxo‐eremophila‐6,9‐dien‐12‐oic acid (1), 8‐[(β‐D‐glucopyranosyl)oxy]eremophila‐1(10),8,11‐trien‐2‐one (2), and 4‐[(β‐D‐glucopyranosyl)oxy]pinoresinol (4). Their structures were elucidated by 1D‐ and 2D‐NMR as well as HR‐ESI‐MS analyses, and by comparison of the spectroscopic data with those reported for structurally related compounds.
Study on the Chemical Constituents of Daphniphyllum angustifolium
Authors: Bai Haiyun , Hu Lihong 
Published: May 2006

AbstractSeven new iridoid glucosides, 1–7, two new phenyl glucosides, 8 and 9, along with eight known compounds were isolated from the bark of Daphniphyllum angustifolium. Their structures were established by ESI‐MS and by 1D‐ and 2D‐NMR spectroscopic methods.
Surface‐Roughness Evolution During the Cementation of Silver Ions on Solid Copper in Aqueous Sulfuric Acid Solution
Authors: Sulka Grzegorz D. , Jaskuła Marian 
Published: May 2006

AbstractThe evolution of the surface roughness during cementation of Ag+ conducted either in O2‐free or O2‐saturated aqueous H2SO4/CuSO4 was investigated at two different initial concentrations of Ag+. The kinetics data of the process determined previously in the rotating cylinder were linked directly with scanning‐electron‐microscope (SEM) images and surface‐height‐distribution diagrams calculated for various cementation times. It was found that, at the beginning of the process, the surface roughness decreases due to formation of a flat Ag layer on the top of the surface, independent of the presence or absence of O2 in the system. With increasing reaction time, an increase in the surface roughness was observed. The rate enhancement of the process is mainly responsible for the increase of the surface roughness in the O2‐saturated solutions, especially at the higher initial Ag+ concentration (100 mg/dm3). The rate enhancement observed at a latter stage of the process, connected with the increase of the effective surface area of the cathodic sites, was separated from the rate enhancement induced by the competitive chemical process occurring in O2‐free solution. The difference in the mechanisms of the processes conducted under aerobic and anaerobic conditions was reflected in the surface‐heigth distributions calculated from the SEM images.
Terpenoids from the Roots of Ligularia muliensis
Authors: Wu Qiu‐Hong , Liu Chun‐Mei , Chen Yan‐Jun , Gao Kun 
Published: May 2006

AbstractThree new eremophilane‐type sesquiterpenes, (6β,8α)‐6‐(acetyloxy)‐8‐hydroxyeremophil‐7(11)‐en‐12,8‐olide (1), (6α,8α)‐6‐hydroxyeremophil‐7(11)‐en‐12,8‐olide (2), and (6α,8α)‐6‐(acetyloxy)eremophil‐7(11)‐en‐12,8‐olide (3) ((8α)‐eremophil‐7(11)‐en‐12,8‐olide = (4aR,5S,8aR,9aS)‐4a,5,6,7,8,8a,9,9a‐octahydro‐3,4a,5‐trimethylnaphtho[2,3‐b]furan‐2(4H)‐one), besides the recently elucidated eremoligularin (4) and bieremoligularolide (5), as well as a new highly oxygenated monoterpene, rel‐(1R,2R,3R,4S,5S)‐p‐menthane‐1,2,3,5‐tetrol (12), together with six known constituents, i.e., the sesquiterpenes 6 and 7, the norsesquiterpenes 8–10, and the monoterpene 13, were isolated from the roots of Ligularia muliensis. In addition, an attempt to dimerize 1 to a bieremophilenolide (Scheme) resulted in the generation of the new derivative (6β,8β)‐6‐(acetyloxy)‐8‐chloroeremophil‐7(11)‐en‐12,8‐olide (11). The new structures were established by means of detailed spectroscopic analysis (IR, FAB‐, EI‐, or HR‐ESI‐MS as well as 1D‐ and 2D‐NMR experiments). Compounds 4 and 5 were evaluated for their antitumor effects in vitro (Table 3).
One‐Step Synthesis of Dialkyl 2‐[(4‐Methylphenyl)sulfonyl]‐1H‐pyrrole‐3,4‐dicarboxylates by Reaction of Acetylenedicarboxylates with ‘Tosylmethyl Isocyanide’ (TsMIC) and Triphenylphosphine
Authors: Alizadeh Abdolali , Masrouri Hassan , Rostamnia Sadegh , Movahedi Farnaz 
Published: May 2006

AbstractThe reactive 1 : 1 adducts in the reaction between Ph3P and dialkyl acetylenedicarboxylates have been trapped with ‘tosylmethyl isocyanide’ (TsMIC; 1) to yield dialkyl 2‐[(4‐methylphenyl)sulfonyl]‐1H‐pyrrole‐3,4‐dicarboxylates 3 (Scheme 1). The structures of the highly functionalized compounds 3 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2).
Convenient Synthesis of 1H‐Indol‐1‐yl Boronates via Palladium(0)‐Catalyzed Borylation of Bromo‐1H‐indoles with ‘Pinacolborane’
Authors: Stadlwieser Josef F. , Dambaur Markus E. 
Published: May 2006

AbstractAn atom‐economic Pd0‐catalyzed synthesis of a series of pinacol‐type indolylboronates 3 from the corresponding bromoindole substrates 2 and pinacolborane (pinBH) as borylating agent was elaborated. The optimal catalyst system consisted of a 1 : 2 mixture of [Pd(OAc)2] and the ortho‐substituted biphenylphosphine ligand L‐3 (Scheme 4, Table). Our synthetic protocol was applied to the fast, preparative‐scale synthesis of 1‐substituted indolylboronates 3a–h in the presence of different functional groups, and at a catalyst load of only 1 mol‐% of Pd.
Synthesis of 1,2‐Disubstituted Carbocyclic Nucleoside Analogues of Cytidine
Authors: González‐Moa María José , Besada Pedro , Terán Carmen , Santana Lourdes , Uriarte Eugenio , Viña Dolores 
Published: May 2006

AbstractThe synthesis of new 1,2‐disubstituted, five‐ or six‐ring‐carbocyclic nucleoside analogues of cytidine, compounds 1 and 2a–d, are described. These compounds were obtained by aminolysis, starting from the corresponding uracil derivative, via nucleophilic displacement of a triazolyl (Scheme 1) or a (2,4,6‐triisopropylphenyl)sulfonyl (TPS) group (Scheme 2) at 4‐position of the pyrimidine ring.
Functionalized Imides by Regioselective Ozonation
Authors: Poschenrieder Hermann , Stachel Hans‐Dietrich , Eckl Eduard , Jax Sabine , Polborn Kurt , Mayer Peter 
Published: May 2006

AbstractOzonations of alkoxy‐ and (acyloxy)‐substituted alkylidene‐lactams 1 and 5 or of the alkylidene‐sultams 9 and 10 proceeded by regioselective cleavage of the exocyclic CC bonds (Schemes 1 and 2). These bonds are part of an enamide system and, therefore, possess considerable polarity as shown by 13C‐NMR spectra. As a result, the partly known maleimides 3 and 6 or the ‘sulfonimides’ 11 were obtained. Compounds 3 and 11 reacted with diazomethane to give the highly reactive bicyclic derivatives 8 and 12, respectively. The cinnamylidene‐lactames 16a,b were converted by selective ozonolysis mainly into the formylmethylene lactames 17a,b (Scheme 3). The amino‐substituted aldehyde 20 bears a structural relationship to the lactone antibiotic basidalin 21a. The tendency of some donor‐substituted maleimides to undergo [2 + 2] cycloadditions was assessed (Scheme 4). The configuration of the photodimers 22a,b and 24a,b was established by X‐ray crystallography.
Two New Pigments from the Fruiting Bodies of the Basidiomycete Lactarius deliciosus
Authors: Yang Xiao‐Long , Luo Du‐Qiang , Dong Ze‐Jun , Liu Ji‐Kai 
Published: May 2006

AbstractTwo new, red‐colored azulene pigments, 7‐(1,2‐dihydroxy‐1‐methylethyl)‐4‐methylazulene‐1‐carbaldehyde (1) and 7‐acetyl‐4‐methylazulene‐1‐carbaldehyde (2), were isolated from the fruiting bodies of the basidiomycete Lactarius deliciosus, together with a related, known compound (3). Their structures were established on the basis of spectroscopic evidence including 2D‐NMR experiments.
Studies on the Flash Vacuum Thermolysis of Thiones of Selected N‐, O‐, and S‐Heterocycles
Authors: Drewnowski Tomasz , Leśniak Stanisław , Mlostoń Grzegorz , Siedlecka Renata , Skarżewski Jacek 
Published: May 2006

AbstractThermal decomposition of thiones of selected N‐, O‐ and S‐heterocycles under flash vacuum thermolysis conditions was investigated. In the case of six‐membered 4H‐3,1‐benzoxathiin‐4‐thione 6, the course of the reaction depended on the substitution pattern at C(2) (Scheme 3). Thus, the 2‐unsubstituted derivative 6a led to the unstable product 2, which upon treatment with MeOH was converted quantitatively into methyl 2‐mercaptobenzoate (7). The analogous thermolysis of the 2,2‐dimethyl derivative 6b yielded 2‐methyl‐4H‐1‐benzothiopyran‐4‐thione (8) as a sole product. In the case of thiophthalide derivatives 15, a thermal rearrangement in the gas phase leading to the corresponding benzo[c]thiophen‐1(3H)‐ones 16 in high yields was observed (Scheme 6). Unexpectedly, thionation of 1,3‐oxathiolan‐5‐one 17 with Lawesson's reagent under standard conditions led to 1,2‐dithietane derivative 19, which, after the gas‐phase thermolysis, underwent a ring enlargement to yield 3H‐1,2‐dithiole 20 (Scheme 7). The six‐membered 4H‐1,3‐benzothiazine‐4‐thione 21 was shown to give three products: phenanthro[9,10‐c]‐1,2‐dithiete (22), 3H‐1,3‐benzodithiole‐3‐thione (23), and N‐(3H‐1,2‐benzodithiol‐3‐ylidene)prop‐2‐en‐1‐amine (24) (Scheme 8). The latter is the product of the initial reaction, whereas 22 and 23 are postulated to be formed as secondary products of the conversion of the intermediate 6‐(thioxomethylene)cyclohexa‐2,4‐diene‐1‐thione (26) (Schemes 9 and 10).
Intravascular lymphoma: a neoplasm of ‘homeless’ lymphocytes?
Authors: Ponzoni Maurilio , Ferreri Andrés J. M. 
Published: May 2006

AbstractIntravascular lymphoma (IVL) is an extremely rare form of non‐Hodgkin lymphoma characterized by almost exclusive growth of neoplastic lymphocytes within blood vessel lumen. IVL is morphologically characterized in most instances by large cells with B‐cell lineage. IVL is an aggressive and usually disseminated disease that predominantly affects elderly patients, resulting in poor PS, B‐symptoms, anemia, and high lactate dehydrogenase serum level. The brain and skin are the most commonly involved sites; nodal disease is rare. Survival after conventional chemotherapy is disappointing, with a relevant impact of diagnostic delay and lethal complications.Notwithstanding these results, IVL limited to the skin (cutaneous variant) is a favorable presentation with distinctive clinical characteristics. Moreover, differences in clinical presentation with Eastern Countries IVL cases, mostly associated with hemophagocytic syndrome, do exist. Intensive combinations containing drugs with higher central nervous system bioavailability are needed in cases with brain involvement; the role of high‐dose chemotherapy with autologous stem cell transplantation should be investigated in younger patients with unfavorable features. The present review will discuss the most recent acquisitions related either to diagnosis and immunophenotypic/biologic characteristics as well as clinical/therapeutic issues of IVL. Copyright © 2006 John Wiley & Sons, Ltd.
Application of the SHETRAN basin‐scale, landslide sediment yield model to the Llobregat basin, Spanish Pyrenees
Authors: Bathurst James C. , Burton Aidan , Clarke Barry G. , Gallart Francesc 
Published: May 2006

AbstractThe first application of the SHETRAN basin‐scale, landslide erosion and sediment yield model is carried out for a major landsliding event in the upper 505 km2of the Llobregat basin, in the eastern Spanish Pyrenees, in November 1982. The model simulates the spatial distribution of shallow landslides and their sediment yield. Acknowledging uncertainty in the model parameter evaluation, the aim of the application was not to reproduce the observed occurrence of landslides as accurately as possible with one simulation, but to bracket the observed pattern with several simulations representing uncertainty in the key input conditions. Bounds on the landslide simulations were thus determined as a function of uncertainty in the vegetation root cohesion (used in the model factor of safety calculations). The resulting upper bound considerably overestimates the observed pattern (17 000 landslides compared with an observation of around 700), but it reproduces several of the principal clusters in the observed pattern. The lower bound contains around 500 landslides. The sediment yield estimates (2670–14 630 t km−2) are comparable to measurements elsewhere in the Pyrenees for extreme events. The results demonstrate an ability to simulate the basin‐scale landslide response to a rainfall event and the resulting sediment yield. They also highlight the need for further research in setting the uncertainty bounds and in avoiding large overestimates of landslide occurrence arising in part from a current inability to model small‐scale controls for a basin of the given size. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of groundwater–surface water interactions on the water balance of a mesoscale lowland river catchment in northeastern Germany
Authors: Krause Stefan , Bronstert Axel 
Published: May 2006

AbstractThe glacially formed northeastern German lowlands are characterized by extensive floodplains, often interrupted by relatively steep moraine hills. The hydrological cycle of this area is governed by the tight interaction of surface water dynamics and the corresponding directly connected shallow groundwater aquifer. Runoff generation processes, as well as the extent and spatial distribution of the interaction between surface water and groundwater, are controlled by floodplain topography and by surface water dynamics.A modelling approach based on extensive experimental analyses is presented that describes the specific water balance of lowland areas, including the interactions of groundwater and surface water, as well as reflecting the important role of time‐variable shallow groundwater stages for runoff generation in floodplains. In the first part, experimental investigations of floodplain hydrological characteristics lead to a qualitative understanding of the water balance processes and to the development of a conceptual model of the water balance and groundwater dynamics of the study area. Thereby model requirements which allow for an adequate simulation of the floodplain hydrology, considering also interactions between groundwater and surface water have been characterized. Based on these analyses, the Integrated Modelling of Water Balance and Nutrient Dynamics (IWAN) approach has been developed. This consists of coupling the surface runoff generation and soil water routines of the deterministic, spatially distributed hydrological model WASIM‐ETH‐I with the three‐dimensional finite‐difference‐based numerical groundwater model MODFLOW and Processing MODFLOW. The model was applied successfully to a mesoscale subcatchment of the Havel River in northeast Germany. It was calibrated for two small catchments (1·4 and 25 km2), where the importance of the interaction processes between groundwater and surface waters and the sensitivity of several controlling parameters could be quantified. Validation results are satisfying for different years for the entire 198 km2 catchment. The model approach was further successfully tested for specific events. The experimental area is a typical example of a floodplain‐dominated landscape. It was demonstrated that the lateral flow processes and the interactions between groundwater and surface water have a major importance for the water balance and periodically superimposed on the vertical runoff generation. Copyright © 2006 John Wiley & Sons, Ltd.
Transcriptional census of 36 microdissected colorectal cancers yields a gene signature to distinguish UICC II and III
Authors: Groene Joern , Mansmann Ulrich , Meister Reinhard , Staub Eike , Roepcke Stefan , Heinze Maya , Klaman Irina , Brümmendorf Thomas , Hermann Klaus , Loddenkemper Christoph , Pilarsky Christian , Mann Benno , Adams Hans‐Peter , Buhr Heinz Johannes , Rosenthal André 
Published: May 2006

AbstractUICC stage II and III colorectal cancers (CRC) differ fundamentally in prognosis and therapeutic concepts. To analyze differential gene expression between both stages and to establish a relationship between molecular background and clinical presentation, tumor material from 36 unselected consecutive patients presenting with sporadic CRC, 18 UICC stage II and 18 UICC stage III, were laser microdissected to separate epithelial tumor cells. Gene expression levels were measured using U133A Affymetrix gene arrays. Twelve CRC associated signal transduction pathways as well as all 22,000 probe sets were screened for differential gene expression. We identified a signature consisting of 45 probe sets that allowed discrimination between UICC stage II and stage III with a rate of correct classification of about 80%. The most distinctive elements in this signature were the gene GSTP‐binding elongation factor (GSPT2) and the transcription factor HOXA9. Differential expression of these genes was confirmed by quantitative real‐time polymerase chain reaction (p(HOXA9) = 0.04, p(GSTP2) = 0.02). Despite the reliability of the presented data, there was no substantial differential expression of genes in cancer‐related pathways. However, the comparison with recently published data corroborates the 45 gene signature showing structural agreement in the direction of fold changes of gene expression levels for our set of genes chosen to discriminate between both stages. © 2006 Wiley‐Liss, Inc.