bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthese optisch aktiver Butenolide und γ‐Lactone aus β,γ‐ungesättigten Carbonsäureestern mit der asymmetrischen Dihydroxylierung nach Sharpless
Authors: Harcken Christian , Brückner Reinhard 
Published: July 2007

Nichtkonjugierte ungesättigte Ester 1 und AD‐Mix α oder AD‐Mix β ergeben cis‐konfigurierte γ‐Alkyl‐β‐hydroxy‐γ‐lactone 2 ‐ breit einsetzbare Vorläufer γ‐chiraler Butenolide und γ‐chiraler Butyrolactone von mittlerer bis sehr hoher Enantiomerenreinheit. Dies zeigen die Synthesen der Naturstoffe 3 (92% ee), 4 (95% ee), 5 (97% ee) und 6 (78% ee).magnified image
Ein hochstabiler Silber(I)‐Komplex mit einem makrocyclischen Liganden
Authors: Gyr Thomas , Mäcke Helmut R. , Hennig Michael 
Published: July 2007

Die höchste bekannte Bindungskonstante für Silber(I)‐Ionen (lg K = 19.63) wurde bei einem Silberkomplex (Struktur im Kristall siehe rechts) mit einem auf Cyclen basierenden Liganden gemessen. Dieser enthält vier Stickstoff‐ und vier Schwefelatome, aber dennoch bevorzugt das weiche Silber(I)‐Ion die Koordination durch die Stickstoffatome und bindet im Festkörper nur zwei Schwefelatome. Der Chelatligand wurde für eine therapeutische In‐vivo‐Anwendung des β‐strahlenden Radionuclids 111Ag entwickelt.magnified image
Ein ABC‐Ringanalogon von Kapurimycin A3: Synthese und Wirksamkeit in der DNA‐Alkylierung
Authors: Nakatani Kazuhiko , Okamoto Akimitsu , Saito Isao 
Published: July 2007

Mit einer 5′‐GPu‐3′‐Sequenzselektivität, die der des natürlichen Antitumor‐Antibioticums Kapurimycin A3 1 stark ähnelt, spaltet dessen ABC‐Ringanalogon 2 DNA sehr effektiv über eine Guaninalkylierung. Wesentlich für die Spaltungsaktivität ist die reaktive Alkenylepoxidgruppe in der Seitenkette und die starke Intercalation der aromatischen Einheit von 1 und 2 in den DNA‐Duplex, wie anhand der erheblich geringeren Spaltungsaktivität eines AB‐Ringanalogons deutlich wurde.magnified image
Konformationskontrolle in Polymetall‐Mesocyclen durch eine Metall‐Metall‐Bindung: das erste Beispiel für eine Hg‐Cu‐Wechselwirkung
Authors: Bodensieck Ulf , Braunstein Pierre , Knorr Michael , Strampfer Martin , Bénard Marc , Strohmann Carsten 
Published: July 2007

Ein zehngliedriger, cyclischer Komplex mit T‐förmigem CuHgFe2‐Gerüst ist das Ergebnis einer bindenden Cu‐Hg‐Wechselwirkung (Cu‐Hg = 2.668(6) Å). Dieser Komplex zeigt in Lösung eine Bewegung, die einem “molekularen Torsionspendel” ähnelt (siehe unten). So wird eine die vier Metallatome enthaltende gemittelte Spiegelebene erzeugt, im Kristall liegt jedoch nur eine C2‐Achse vor.magnified image
Komplexe mit Sb2‐ und cyclo‐Sb3‐Liganden: die Tetrahedrane [{C5H5(CO)2Mo}2Sb2], [C5H5(CO)2MoSb3] und [C5Me5(CO)2MoSb3]
Authors: Breunig Hans Joachim , Rösler Roland , Lork Enno 
Published: July 2007

Als Antimonquelle für Komplexe mit substituentenfreien Sbn‐Liganden eignet sich die Vierringverbindung (tBuSb)4. Die Umsetzung mit [{C5H5(CO)3Mo}2] liefert die Tetrahedrane 1 und 2. Mit [{C5Me5(CO)3Mo}2] reagiert (tBuSb)4 zu 3. Bei 2 und 3 handelt es sich um die ersten Komplexe mit dem cyclo‐Sb3‐Liganden. Im Kristall sind sie über Sb‐Sb‐Wechselwirkungen miteinander verknüpft.magnified image
Formselektive Hydrierungen und Oxidationen an platinhaltigen, ultramikroporösen Heteropolyoxometallaten
Authors: Yoshinaga Yusuke , Seki Kohei , Nakato Teruyuki , Okuhara Toshio 
Published: July 2007

Bevorzugt die kleineren Moleküle werden in Gegenwart der ultramikroporösen (Porendurchmesser <5.9 Å), platinhaltigen (0.5 Gew.‐%) Heteropolyoxometallatverbindung Pt/Cs2.1H0.9PW12O40 oxidiert und hydriert. Dies ergaben Untersuchungen mit Methan/2,2‐Dimethylpropan bzw. Ethen/Cyclohexen (schematische Darstellung rechts).magnified image
Enantioselektive Synthese von Altohyrtin C (Spongistatin 2): Verknüpfung der Fragmente und Korrektur der Strukturzuordnung
Authors: Evans David A. , Trotter B. Wesley , Côté Bernard , Coleman Paul J. , Dias Luiz Carlos , Tyler Andrew N. 
Published: July 2007

Die erste Totalsynthese eines Spongipyran‐Makrolids, des Altohyrtins C (Spongistatin 2; siehe unten), wurde erfolgreich abgeschlossen. Die aus Meeresschwämmen isolierten Spongipyrane gehören zu den stärksten cytotoxischen Verbindungen und wirken gegen mehrere menschliche Krebszellinien. Während die vorgeschlagenen Strukturen für die unabhängig isolierten Altohyrtine und Spongistatine im wesentlichen gleich sind, unterscheiden sie sich in der relativen Konfiguration der Untereinheiten. Durch die Totalsynthese wurde nun die vorgeschlagene Struktur der Altohyrtine bestätigt und nachgewiesen, daß Altohyrtin C und Spongistatin 2 identisch sind.magnified image
Erzeugung enantioselektiver Biokatalysatoren für die Organische Chemie durch In‐vitro‐Evolution
Authors: Reetz Manfred T. , Zonta Albin , Schimossek Klaus , Liebeton Klaus , Jaeger Karl‐Erich 
Published: July 2007

Evolution im Reagensglas: Mit der fehlerhaften Polymerasekettenreaktion als Methode der Zufallsmutagenese, einem effizienten Genexpressionssystem und einem Screening‐Test zur raschen Identifizierung enantioselektiver Katalysatoren läßt sich der ee‐Wert einer unselektiven Lipase‐katalysierten Esterhydrolyse schrittweise erhöhen (siehe Bild rechts).magnified image
Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery (Br J Surg 2007; 94: 395–403)
Authors: Koelemay M J , Vahl A C 
Published: July 2007

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Policy governance: The story so far
Authors: Oliver Caroline 
Published: July 2007

AbstractSometimes it takes a crisis to provoke change. The Enron debacle is just such a crisis, and with the first book on Policy Governance in the corporate sector hitting the shelves this summer, this could be a pivotal moment in the history of the development of Policy Governance. Caroline Oliver marks this occasion by laying down the story so far. Perhaps understanding how far Policy Governance has come will lay the groundwork for the future; this article will at least provide a record of the state of Policy Governance in the summer of 2002.
When owners don't agree
Authors: Oliver Caroline 
Published: July 2007

AbstractPolicy Governance boards know that the source of their authority is their owners, and sometimes that means that their problems have just begun. It is all very well knowing clearly who your owners are, but it can get pretty trick)' if they turn out to have conflicting views about what the organization should be about or where it should go. A surprising number of boards are in this position, and how they handle this problem can be a hallmark of their leadership.
The mighty meeting
Authors: Oliver Caroline 
Published: July 2007

AbstractIn this article, Caroline Oliver considers, in depth, the subject of Policy Governance and board meetings. She shows how Policy Governance principles of ownership, accountability, board holism, delegation, and crafting of effective policy can serve as the groundwork for successful meetings. From this starting point, with a little critical attention, board members can take control of their meetings, making them not only more productive and efficient but even enlightening and fun.
Using information technology to sustain policy governance
Authors: Tooley Ray 
Published: July 2007

AbstractCan Policy Governance provide a long‐term sustainable model for owner‐accountable effective governance? The answer is a resounding yes, but there are many challenges boards face in becoming mature and seasoned users of this comprehensive system. This article will examine some of the obstacles to achieving user‐friendly Policy Governance sustainability and how information technology can be used to overcome the barriers on the road to success.
ADME Investigations of Unnatural Peptides: Distribution of a 14C‐Labeled β 3‐Octaarginine in Rats
Authors: Weiss H. Markus , Wirz Bernard , Schweitzer Alain , Amstutz René , Perez Maria I. Rodriguez , Andres Hendrik , Metz Yves , Gardiner James , Seebach Dieter 
Published: July 2007

AbstractThe highly positively charged, cell‐penetrating β 3‐octaarginine has been prepared with a radioactive label by acetylation at the N‐terminus with a doubly 14C‐labeled acetyl group (14CH314CO). With the radioactive compound, an ADME study (Absorption, Distribution, Metabolism, Excretion) was performed in male rats following an intravenous or oral dose of 1 mg/kg. Sampling was carried out after periods ranging from 5 min to 4 d or 7 d for blood/excretia and quantitative whole‐body autoradioluminography (QWBA), respectively. After p.o. dosing, no systemic exposure to peptide‐related radioactivity was observed, and the dose was completely excreted in the feces within 24 h suggesting the absence of relevant absorption; less than 3% of the i.v. dose was excreted from the animals within 4 d. Blood levels, after i.v. dosing, dropped within 4 d to less than 2% of Cmax and decreased afterwards only very slowly. No metabolites were observed in the systemic circulation. QWBA Data indicated that the distribution of the acetyl‐β‐octaarginine‐related radioactivity in the organs and tissues shifted over time. Notably, after 7 d, the highest concentration was measured in the lymph nodes, and the largest amount was found in the liver. A comparison with the results of two previous ADME investigations of β‐peptides (cf. Table 1) reveals that the distribution of the compounds within the animals is structure‐dependent, and that there is a full range from oral availability with rather rapid excretion (of a tetrapeptide) to essentially complete lack of both oral absorption and excretion after i.v. administration (of a highly charged octapeptide). A discussion is presented about the in vivo stability and ‘drug‐ability’ of peptides. In general, β‐peptides bearing proteinogenic side chains are compared with peptides consisting entirely of D‐α‐amino acid residues (the enantiomers of the ‘natural’ building blocks), and suggestions are made regarding a possible focus of future biomedical investigations with β‐peptides.
Chemical Composition and Antimicrobial Activity of the Essential Oil of Teucrium ramosissimum (Lamiaceae)
Authors: Sghaier Mohamed Ben , Chraief Imed , Skandrani Ines , Bouhlel Ines , Boubaker Jihed , Kilani Soumaya , Neffati Aïcha , Mahmoud Amor , Hammami Mohamed , Chekir‐Ghedira Leila , Ghedira Kamel 
Published: July 2007

AbstractThe phytochemical composition of the essential oil of Teucrium ramosissimum (aerial parts), harvested in a mountainous region of Tunisia, was analyzed. A total of 68 compounds, accounting for 99.44% of the essential oil, were identified by GC and GC/MS. The major compounds were β‐eudesmol (61; 44.52%), caryophyllene oxide (56; 9.35%), α‐thujene (1; 5.51%), sabinene (4; 4.71%), and T‐cadinol (59; 3.9 %). The essential oil, which is being used in Tunisian folk medicine against infectious diseases, was tested for its antimicrobial properties against five different bacteria, and found to have weak to moderate activity, with minimal‐inhibitory‐concentration (MIC) and minimal‐bactericidal‐concentration (MBC) values in the range 0.24–0.36 and 1.3–2.9 mg/ml, resp.
Specific Recognition of Loop DNA by Dicationic Porphyrins
Authors: Weng Xiao‐Cheng , Huang Jing , Wu Song , Ren Li‐Ge , Weng Li‐Wei , Zhu Shu‐Gao , Zhou Xiang 
Published: July 2007

AbstractA series of dicationic porphyrins were found to specifically recognize loop structures of oligodeoxynucleotides, and to selectively oxidize guanine residues upon photo‐irradiation at micromolar concentrations. These compounds could, thus, be employed as promising structural probes for specific secondary DNA structures. The production of singlet oxygen (1O2) is responsible for the DNA‐modification profiles. Both UV‐titration and thermal‐melting experiments indicate that the strong affinity of the charged porphyrins towards DNA loops is responsible for these molecular‐recognition phenomena.
First Synthesis of 12‐Oxosoladulcidine and Its Derivatives as Potential Antitumor Steroidal Alkaloids
Authors: Zha Xiaoming , Hou Yingwei , Sun Hongbin , Zhang Yihua 
Published: July 2007

AbstractThe first synthesis of 12‐oxosoladulcidine (=(3β,5α,22α,25R)‐3‐hydroxyspirosolan‐12‐one; 4) is reported, and its structure was confirmed by single‐crystal X‐ray diffraction analysis. Compound 4 was readily obtained in five steps in an overall yield of 31%, starting from hecogenin (5). By slightly modifying the synthetic protocol, eight analogues of 4 were also prepared. The title compound and its derivatives are expected to be potent antitumor alkaloids, since structurally closely related to the known antitumor agents soladulcidine (2) and hecogenin (5).
Synthesis and DNA Binding/Cleavage of Mononuclear Copper(II) Phenanthroline/Bipyridine Proline Complexes
Authors: Reddy Pulimamidi R. , Raju Nomula , Manjula Pallerla , Reddy Karnati V. G. 
Published: July 2007

AbstractThe complexes [CuII(phen)(L‐Pro)(H2O)]+ClO$\rm{ _4^ - }$ (1; phen=1,10‐phenanthroline) and [CuII(bipy)(L‐Pro)(H2O)]+ClO$\rm{ _4^ - }$ (2; bipy=2,2′‐bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI‐MS, elemental analysis, and theoretical calculations. The metal center was found in a square‐pyramidal geometry. UV/VIS, thermal‐denaturation, and fluorescence‐spectroscopic studies were conducted to assess the interaction of the complexes with CT‐DNA. An intercalative mode of binding was found, with intrinsic binding constants (Kb) of 3.86×103 and 4.6×103 M−1 and Stern–Volmer quenching constants (K) of 0.15 and 0.11 for 1 and 2, respectively. Interestingly, none of the CuII complexes was able to cleave pUC‐19 DNA, which is attributed to the absence of a Pro amide H‐atom and inhibition of the formation of an OH radical from the axially coordinated H2O molecule.
The theory of the case: What prosecutors can teach us about competitive intelligence
Authors: Ogilvie Timorhy J. 
Published: July 2007

AbstractCompetitive intelligence professionals can hone their investigative and analytical skills by applying the lessons of criminal prosecutors. These include using prosecutorial discretion, developing a case theory, testing it through field research, using informants and corroboration, abiding by ethical rules, shadowing the defense, and letting the facts speak. The author provides business analogs for each of these approaches. The cornerstone is the use of the scientific method for hypothesis testing. As Sherlock Holmes knew, any single fact may seem insignificant, but the coupling of seemingly innocuous facts may prove a key to the analysis (or, in this case, the competitive situation). Anticipating the tactics of “the defense” (the competitor) can offset its probable maneuvers. A company can even benefit from staging a “Kangaroo Court” in which an internal team and a “shadow” team representing the competitor argue their business cases before a “court” of experts in the field. © 1997 John Wiley & Sons, Inc.
Classification of Wines Based on Combination of 1H NMR Spectroscopy and Principal Component Analysis
Authors: Du Yuan‐Yuan , Bai Guo‐Yun , Zhang Xu , Liu Mai‐Li 
Published: July 2007

AbstractA combination of 1H nuclear magnetic resonance (NMR) spectroscopy and principal component analysis (PCA) has shown the potential for being a useful method for classification of type, production origin or geographic origin of wines. In this preliminary study, twenty‐one bottled wines were classified/separated for their location of production in Shacheng, Changli and Yantai, and the types of the blended, medium dry, dry white and dry red wines, using the NMR‐PCA method. The wines were produced by three subsidiary companies of an enterprise according to the same national standard. The separation was believed to be mainly due to the fermentation process for different wines and environmental variations, such as local climate, soil, underground water, sunlight and rainfall. The major chemicals associated with the separation were identified.
Stylissamides A–D – New Proline‐Containing Cyclic Heptapeptides from the Marine Sponge Stylissa caribica
Authors: Schmidt Gesine , Grube Achim , Köck Matthias 
Published: July 2007

AbstractFour new cyclic heptapeptides, stylissamides A–D (1–4), were isolated from the Caribbean sponge Stylissa caribica. The structures of these metabolites were elucidated by NMR and MS/MS methods. The peptides contain three and, in one case, four proline residues. The sequence assignment of 1–4 by NMR was supported by fragmentations in HR‐MS/MS measurements. The absolute configuration of all amino acid residues was assigned as L using Marfey's method and the OPA method.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Regio‐ and Stereoselective Synthesis of Tri‐ and Tetrasubstituted Alkenes by Introduction of CO2 and Alkylzinc Reagents into Alkynes
Authors: Mori Miwako 
Published: July 2007

AbstractCarbon dioxide (CO2) is a useful C‐1 unit resource in synthetic organic chemistry. It was known that a low‐valent nickel complex could coordinate to CO2 to form an oxanickelacyclopropane, which reacts with a terminal alkyne to form an oxanickelacyclopentene. Transmetalation of the oxanickelacyclopentene with an alkylzinc reagent gives a trisubstituted alkene in high yield after hydrolysis. A novel synthetic method for heterocycles from terminal alkynes containing suitably positioned heteroatoms was developed, using this alkylative carboxylation followed by a hetero‐Michael reaction. Using this procedure, the synthesis of erythrocarine, one of the erthrina alkaloids, the total synthesis of which had not previously been achieved, was developed. Additionally, a regioselective synthesis of tetrasubstituted alkenes from disubstituted alkynes was also examined. A silylated alkyne was used and a tetrasubstituted alkene was obtained regioselectively. This reaction was further developed into a nickel‐catalyzed reaction, and the effects of substituents on the alkyne were also examined. It was found that an alkyne containing a tert‐butyl or a phenyl group predominantly gave one tetrasubstituted alkene. The results indicated that conjugation of the carboxyl group with the substituent in the oxanickelacyclopentene is important for the formation of oxanickelacycles, and that the thermodynamically more stable oxanickelacycle should be formed. Thus, thermodynamically more stable alkenes are formed; that is, an electron‐donating group on the alkene would conjugate with the carboxyl group. Using this procedure, it was possible to synthesize tamoxifen, which is effective for the treatment of metastatic breast cancer and contains a tetrasubstituted alkene in its skeleton.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Determination of the function of the internal branch of the superior laryngeal nerve after thyroidectomy
Authors: Wasserman Jared M. , Sundaram Krishnamurthi , Alfonso Antonio E. , Rosenfeld Richard M. , Har‐El Gady 
Published: July 2007

AbstractBackground.Several unique complications of thyroidectomy exist because of its regional anatomy; they are well studied and reported. A majority of thyroidectomy patients report vague upper aerodigestive tract complaints. Despite this, no formal assessment of the integrity of the internal branch of the superior laryngeal nerve after thyroidectomy exists in the literature.Methods.Thirty three patients undergoing thyroidectomy were prospectively evaluated with preoperative and postoperative laryngopharyngeal sensory testing.Results.Preoperatively, 16 patients (49%) reported dysphagia, and 19 (58%) complained of globus sensation. Postoperatively, 24 (73%) patients complained of dysphagia, and 25 (76%) reported globus sensation. Preoperative sensory testing showed a mean sensory threshold of 2.79 ± 0.51 mm Hg. The mean change in thresholds postoperatively was trivial (0.07 ± 0.29 mm Hg), and did not differ significantly from zero (p = .19).Conclusions.Although most patients report significant difficulty swallowing after thyroidectomy, the sensory nerve to the laryngopharynx remains intact and is not at risk during thyroid surgery. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Iridoid Glycosides from Hedyotis corymbosa
Authors: Jiang Wei , Kuang Li‐Sha , Hou Ai‐Jun , Qian Min , Li Ji‐Zong 
Published: July 2007

AbstractThree new iridoid glycosides, hedycorysides A–C (1–3, resp.), were isolated from the whole plant of Hedyotis corymbosa (Linn.) Lam., along with four known compounds. Their structures were elucidated by extensive 1D‐ and 2D‐NMR analysis, as well as by HR‐ESI‐MS experiments. The three new compounds are the first benzoylated geniposide derivatives from Hedyotis.
Perchloric Acid–Silica (HClO4⋅SiO2)‐Catalyzed Synthesis of 14‐Alkyl‐ or 14‐Aryl‐14H‐dibenzo[a,j]xanthenes and N‐[(2‐Hydroxynaphthalen‐1‐yl)methyl]amides
Authors: Das Biswanath , Kumar D. Nandan , Laxminarayana Keetha , Ravikanth B. 
Published: July 2007

AbstractThe synthesis of 14‐aryl‐ or 14‐alkyl‐14H‐dibenzo[a,j]xanthenes 3 involving the treatment of naphthalen‐2‐ol (1) with arenecarboxaldehydes or alkanals 2 in the presence of HClO4⋅SiO2 as a heterogeneous catalyst was achieved (Table 1), and this reaction was extended to the preparation of N‐[(2‐hydroxynaphthalen‐1‐yl)methyl]amides 5 by a three‐component reaction with urea (4a) or an amide 4b–d as a third reactant (Table 2).
Further Daphniphyllum Alkaloids from the Leaves of Daphniphyllum macropodumMiq.
Authors: Li Zhen‐Yu , Chen Ping , Xu Hong‐Gui , Peng Shu‐Ying , Yang Yi‐Ming , Zhao Zhong‐Zhen , Guo Yue‐Wei 
Published: July 2007

AbstractFive new polycyclic Daphniphyllum alkaloids, macropodumines F (1) and G (2), 17‐oxoyuzurimine (3), and macropodumines H (4) and I (5), were isolated from the leaves of D. macropodum Miq., collected in Sichuan Province, China. The structures and relative configurations of the new compounds – as well as of four known, related alkaloids – were elucidated on the basis of in‐depth spectroscopic and mass‐spectrometric analyses, by chemical derivatization, and by comparison of spectroscopic data with those of known compounds.
Macrocycles Incorporating an Endocyclic But Non‐Sterically‐Hindering Chelate: Synthesis and Structural Studies
Authors: Durola Fabien , Sauvage Jean‐Pierre , Wenger Oliver S. 
Published: July 2007

AbstractTwo rings of different size have been prepared both incorporating a 3,3′‐biisoquinoline (biiq) chelate. The biiq ligand bears phenyl groups at its 8‐ and 8′‐positions, which provide it with an approximate crescent shape. The incorporation of the 8,8′‐diaryl‐3,3′‐biisoquinoline motif in a ring leads to an unusual situation. The complexing site of the macroring is unambiguously pointing towards the inner part of the macrocycle, but, at the same time, it is not sterically hindered, due to the relatively large distance between the coordinating site and the various organic groups belonging to the macrocyclic structure. The synthesis of the two compounds is reported, as well as the X‐ray structure of one of them, which confirms the expected geometrical properties of the molecules.