bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Evaluation of 3‐Fluoro‐2‐piperazinyl‐5,8,13‐trihydro‐5‐oxoquino[1,2‐a][3,1]benzoxazine‐6‐carboxylic Acids as Potential Antibacterial Agents
Authors: Chung Sang J. , Kim Dong H. 
Published: October 2006

Abstract3‐Fluoro‐2‐piperazinyl‐5,8,13‐trihydro‐5‐oxoquino[1,2‐a][3,1]‐benzoxazine‐6‐carboxylic acids were designed and synthesized as potential DNA gyrase inhibitors and antibacterial agents. The design rationale rests on the proposition made by Ohta and Koga that in order for N1‐aryl substituted quinolones to posses antibacterial activity the N1‐aryl ring should be oriented out of the plane of the quinolone ring. α‐[Bis(methylthio)methylene]‐2,4,5‐trifluoro‐β‐oxobenzenepropanoic acid tert‐butyl ester (6) obtained by the treatment of 2,4,5‐trifluoro‐β‐oxobenzenepropanoic acid tert‐butyl ester (5) with carbon disulfide and methyl iodide in the presence of cesium carbonate was used as a key intermediate, yielding tert‐butyl 2,3‐difluoro‐5,8,13‐trihydro‐5‐oxoquino[1,2‐a][3,1]benzoxazine‐6‐carboxylate (8) upon treatment with 2‐aminobenzyl alcohol. The coupling of 8 with piperazines followed by the hydrolysis of the ester under acidic conditions afforded the desired product (3). Contrary to expectation, both compounds (3a,b) were, however, devoid of antibacterial activity, suggesting that for N1‐aryl substituted quinolones to exhibit antimicrobial activity important structural feature(s) other than the conformational requirement of the N1‐aryl ring with respect to the quinolone nucleus should also be satisfied.
Synthesis of 2‐Oxacortexone and its Effect on Ca2+ Uptake in Bovine Spermatozoa
Authors: Frimer Aryeh A. , Aljadeff Gladis , Rubinstein Sara , Breitart Haim 
Published: October 2006

AbstractLow temperature base catalyzed autoxidation (BCA) of the A‐ring of 21‐acetoxypregn‐5‐ene‐3,20‐dione 20‐ethylene ketal (7) resulted in the saponification of the ester with the concomitant formation of 2,21‐dihydroxypregna‐1,4‐diene‐3,20‐dione 20‐ethylene ketal (8) Continued BCA at ambient temperature, converts the latter to 1,21‐dihydroxy‐2‐oxaprogesterone 20‐ethylene ketal (9), which is reduced by NaBH4 to the 2‐oxasteroid, 21‐hydroxy‐2‐oxaprogesterone 20‐ethylene ketal (10). Treatment of enol 8, lactol 9, 9, and lactone 10 with aqueous acid generates the corresponding deprotected analogs 2,21‐dihydroxypregna‐1,4‐diene‐3,20‐dione (enol 11), 1,21‐dihydroxy‐2‐oxaprogesterone (lactol 12), and 2‐oxacortexone (2‐oxadesoxycorticosterone, 21‐hydroxy‐2‐oxaprogesterone, lactone 13). In bovine spermatozoa, neither 2‐oxasteroid ketal 10 nor its deprotected analog 13 stimulated Ca2+ uptake. In high concentration (0.5 mM), the inhibition of Ca2+ uptake is only 37% for 13, as compared to 83% found with the parent steroid, cortexone (desoxycorticosterone, 21‐hydroxyprogesterone, 5). The difference in molecular structure between 13 and 5 indicates the importance of the oxygen atom in ring A in achieving the protective effect of the steroid. Ketalization of the C‐20 carbonyl is not important for protection. Thus it seems that by replacing C‐2 by an oxygen atom we can reduce the biological damage caused by relatively high concentrations of steroid treatment. These results are highly significant when treatment of patients with high doses of steroids is considered.
Synthesis and Evaluation of a Novel Series of Pyrrolizine Derivatives as Dual Cyclooxygenase‐1 and 5‐Lipoxygenase Inhibitors
Authors: Laufer Stefan , Striegel Hans‐Günter , Neher Karola , Zechmeister Pia , Donat Cornelia , Stolingwa Katrin , Baur Sibylle , Tries Susanne , Kammermeier Thomas , Dannhardt Gerd , Kiefer Werner 
Published: October 2006

AbstractThe aim of our study was to investigate structure activity relationship following the replacement of the 6‐phenyl substituent at the 6,7‐diaryl‐2,3‐dihydropyrrolizine template by various heteroaromatic residues. In this context we developed a new, efficient, and highly sensitive test method for the screening of dual cyclooxygenase‐1 (COX‐1) and 5‐lipoxygenase (5‐LOX) inhibitors. We used human platelets as a source of COX‐1 and human PMNLs as a source of 5‐LOX. Both cell types were isolated from the same volume of blood. PGE2 and LTB4 respectively were determined by highly selective and sensitive ELISA kits, using monoclonal antibodies. For a single determination at most 0.5 mL whole blood is needed.
New Carriers for Representative Peptides and Peptide Drugs
Authors: Aboul‐Fadl Tarck , El‐Shorbagi Abdel‐Nasser 
Published: October 2006

Abstract3,5‐Disubstituted tetrahydro‐2H‐1,3,5‐thiadiazine‐2‐thione (THTT) derivatives; 4a–g were prepared and found to be a promising prodrug approach for peptide drugs. The pH profile for their degradation in aqueous buffer solutions was determined using HPLC technique and accounted for, in terms of specific base‐catalyzed reactions. All of the compounds however, showed high acid‐stability. Enzymatic (human serum) hydrolysis of the different derivatives offered an advantageous range of t1/2's, the property that permits controlling onset and duration of actions of drugs.
Zur Prognose der Schalldämmung zweischaliger Membrankonstruktionen
Authors: Maysenhölder Waldemar 
Published: October 2006

AbstractDie Schalldämmung zweischaliger Membrankonstruktionen kann rechnerisch gut vorhergesagt werden, wenn der Hohlraum zwischen den Membranen mit Absorptionsmaterial bedämpft ist. Dies wird an einer Konstruktion mit 20 cm Membranabstand und eingestellter, 10 cm dicker offenporöser Schaumstoffplatte veranschaulicht. Die Berechnungen erfolgen mit dem Programm LAYERS. Eine bisher zur Abschätzung benutzte Formel führt nicht zum Ziel, weil sie die Einfallswinkelabhängigkeit des Schalldurchgangs nicht korrekt berücksichtigt. Bei “leerem”, nur gering bedämpftem Hohlraum ist eine Prognose mit LAYERS im Prinzip ebenfalls möglich. Da jedoch über die Absorption in der Luft‐ oder Gasfüllung und an den seitlichen Hohlraumrändern kaum etwas bekannt ist, sind die Ergebnisse mit größeren Unsicherheiten behaftet. Unklarheiten bestehen außerdem bezüglich der im Prüfstand herrschenden Einfallswinkelverteilungen und deren Einfluß auf die Schalldämmung.
Ein Design‐Tool für den Entwurf von Niedrigenergiebauten
Authors: Keller Bruno , Magyari Eugen 
Published: October 2006

AbstractDas thermisch‐dynamische Verhalten eines Raumes kann mit großer Allgemeingültigkeit auf nur drei Schlüsselparameter zurückgeführt werden. Damit ist die Temperaturentwicklung eines Raumes unter dem alleinigen Einfluß des Außenklimas – seine Leerlauftemperatur – eindeutig bestimmt und berechenbar. Solange diese innerhalb des Komfortbereichs verläuft, wird keine Energie für Heizen oder Kühlen benötigt. Es wird eine Strategie entwickelt, die auf der Maximierung dieser Nullenergiestunden beruht. Mit Hilfe eines Tabellenkalkulations‐Programms und dreier resultierender Grafiken lassen sich die Bestwerte der Schlüsselparameter auf die für die Praxis relevanten Planungsgrößen wie Glasanteil und Glasqualität (U‐Wert, g‐Wert), Bauweise etc. zurückführen. Damit steht ein Werkzeug zur Verfügung, welches sich vor allem für die frühen Phasen des Entwurfs eignet.
Zoologische Gärten in Stadtkultur und Wissenschaft im 19. Jahrhundert
Authors: Jahn Ilse 
Published: October 2006

AbstractThe foundation and administration of European Zoological gardens in the 19th century is analized. It is significant of such new institutions, that they are founded in the large cities, and that most of the founders looked at the great models in Paris and London, which are described first. Further it is shown that the change from princely menageries to public Zoological Gardens is caused both by common interests in people's education and pleasure and by scientific aims which leaded to choose the name Zoological “garden” in analogy to botanical gardens. It seems to be characteristic of such public institutions created by citizens in the 19th century that they are mostly supported by commercial or scientific local societies. This is exemplified by describing the administration of the Zoological gardens of Berlin (1841), Frankfurt (1856) and Hamburg (1863), which initiated also research for acclimatization of wild animals.
Kalmus, Gilge und Würzhalm. Anmerkungen zu einer alten Verwechslungsgeschichte
Authors: Stoll Ulrich 
Published: October 2006

AbstractThe identification of the plant treated by Dioscorides in his chapter “äkopov” Still today gives reason to errors. This fact justifies the presentation of some hitherto neglected aspects of the confusion of the nomenclature referring to this plant. Especially the synonyms of those plants which were confound with or by which the sweet flag (Acorus calamus L.) was substituted are examined in this study of quotations found in herbals and recipes from the antiquity and the Middle Ages up to the early modern times. In order to answer the question which plants were actually used in the practice of pharmacotherapy at times one would propose to compare the corresponding recipes, a method which could lead to a new kind of index of simplicia.
Aspekte angewandter Wissenschaften in Moscheen und Klöstern (Teil I)
Authors: King David A. 
Published: October 2006

AbstractOnly recently have the abundant sources relating to the application of astronomy to the needs of religious ritual in medieval Islam been studied, and it is now possible to write a new chapter in the history of Islamic astronomy. Simple techniques were advocated by the scholars of the religious law, highly sophisticated and complicated solutions were proposed by the Muslim scientists. It is not without interest to compare and contrast this activity, which lasted over a millennium, with that of the monks of the Christian Middle Ages. The history of the latter has not yet been written, and cannot be written from textual sources alone, as is clearly shown by some of the astronomical instruments presented here. The present essay, in which both the Islamic and Christian traditions are discussed side by side for the first time, is very much a preliminary venture, primarily intended to point to the inherent interest of the available materials for the history of science as well as for several other disciplines.
Universitäre Freiräume im Spätmittelalter als Wegbereiter neuzeitlicher Naturwissenschaft
Authors: Markowski Mieczyslaw Hubert 
Published: October 2006

AbstractUniversity freedom in late Middle Ages as a way to modern natural history: The question regarding the relation between faith and natural history in late Middle Ages was answered in different ways. In the way of thinking shaped by Augustinian philosophy there existed, in early Middle Ages, a close connection between natural science and religious belief. In the second half of the 13th century attempts were made at dividing natural science from supernatural sphere. In late Middle Ages it was endeavoured not only to liberate natural history from the domination of theology and metaphysics but also to achieve the autonomous treatment of nature. These endeavours became fully accomplished by Nicolaus Copernicus.
Die Geschichte der Dämpfung an der Laboratoriumswaage
Authors: Jenemann Hans Richard 
Published: October 2006

AbstractHistory of the Damping of Precision Balances. The handling of high precision laboratory balances designed during the 19th century was improved substantially by the addition of ancillary equipment, like rider weights and the application of new weighing techniques, like observation of the swinging pointer in front of a scale. Within the first decades of the present century the optical projection for the inclination range and mechanical counterbalancing was introduced, first for low weights and than for the whole scale range. Notably, fast acting damping of the balance beam oscillations allowed for direct readings of the weighing result and enabled combinations with other measuring techniques. Various damping methodes for engine vibrations and for instrument indications were already known at this time and could be adapted for the special requirements of balances. The present paper deals with the historical roots of damping, starting with simple methods of braking and calming down the movements of the balance, than with the development of damping devices for the laboratory balance, and it includes some neighbouring innovations.
Zwischen Verwaltungsstaat und Industriegesellschaft Die Gründung höherer technischer Bildungsstätten in Deutschland in den ersten Jahrzehnten des 19. Jahrhunderts
Authors: König Wolfgang 
Published: October 2006

AbstractIn Germany, numerous technical schools were established between 1821 and 1836. The main purpose of these schools was to supply public service and industry with technical personnel. Indeed, a great number among the graduates entered positions in mining, military, and public building. The public service's demands influenced the schools' organization and curricula. On the contrary, in the time period before 1870, only few graduates obtained positions in industry. The author's conclusion is, that the technical schools contributed little to the early industrialization in Germany.
Crystal Structure and Physical Properties of New Ternary Gallides Eu2Rh3Ga9 and Eu2Ir3Ga9.
Authors: Sichevych Olga , Schnelle Walter , Prots Yurii , Burkhardt Ulrich , Grin Yurii 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
LiBx (0.82 < x ≤ 1.0) — An Incommensurate Composite Structure Below 150 K.
Authors: Woerle Michael , Nesper Reinhard , Chatterji Tapan K. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Unprecedented Association of [Mo6Br7iYiBr6a]3‐ Cluster Units and [MoIIIBr6]3‐ Complexes: Synthesis, Crystal Structures, and Properties of the Double Salts Rb3 [Mo6Br7iYiBr6a](Rb3[MoBr6])3 (Y: Se, Te).
Authors: Kirakci Kaplan , Cordier Stephane , Perrin Christiane 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Oxidation Activity of Pt3O4 Surfaces and Thin Films
Authors: Seriani Nicola , Pompe Wolfgang , Ciacchi Lucio Colombi 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Metal—Organic Framework Material that Functions as an Enantioselective Catalyst for Olefin Epoxidation.
Authors: Cho So‐Hye , Ma Baoqing , Nguyen SonBinh T. , Hupp Joseph T. , Albrecht‐Schmitt Thomas E. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reductive Deoximation of Aryloximes into Hydrocarbons by Hydrazine/KOH: A Novel Application of the Wolff—Kishner Reduction.
Authors: Nanjundaswamy H. M. , Pasha M. A. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient Synthesis of Various Secondary Amines Through a Titanium(IV) Isopropoxide Mediated Reductive Amination of Ketones.
Authors: Salmi Chanaz , Letourneux Yves , Brunel Jean Michel 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
High Yielding Methyl Esterification Catalyzed by Indium(III) Chloride.
Authors: Mineno Tomoko , Kansui Hisao 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A One‐Pot Selective Deprotective Acetylation of Benzyl Ethers and OTBDMS Ethers Using the BF3×Et2O—NaI—Ac2O Reagent System.
Authors: Brar Anita , Vankar Yashwant D. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cyclizations of α‐Diketones to α‐Hydroxycyclopentenones on Silica Gel in the Absence of Solvent.
Authors: Uhrich Elizabeth A. , Batson William A. , Tius Marcus A. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Recyclable Fluorous (S)‐Pyrrolidine Sulfonamide Promoted Direct, Highly Enantioselective Michael Addition of Ketones and Aldehydes to Nitroolefins in Water.
Authors: Zu Liansuo , Wang Jian , Li Hao , Wang Wei 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhodium(I)‐Catalyzed Carboxylation of Aryl‐ and Alkenylboronic Esters with CO2.
Authors: Ukai Kazutoshi , Aoki Masao , Takaya Jun , Iwasawa Nobuharu 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthetic Method for Multifunctionalized Oligoarenes Using Pinacol Esters of Hydroxyphenylboronic Acids.
Authors: Ishikawa Shunpei , Manabe Kei 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Mannich‐Type Reaction of a Chiral N‐(tert‐Butylsulfinyl) Ketimine with Imines: Application to the Synthesis of Chiral 1,3‐Diamines.
Authors: Zhao Cui‐Hua , Liu Li , Wang Dong , Chen Yong‐Jun 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Indium Triflate Catalyzed Rearrangement of Aryl‐Substituted Cyclopropyl Carbinols to 1,4‐Disubstituted 1,3‐Butadienes.
Authors: Ranu Brindaban C. , Banerjee Subhash 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Interaction of the Azole N‐Sodium Derivatives with Freon‐113: Synthesis of N‐(2,2‐Dichlorotrifluoroethyl)azoles.
Authors: Petko K. I. , Yagupolskii L. M. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Aza‐Payne Rearrangement of α,α‐Disubstituted‐aziridinemethanols.
Authors: Feng Xichun , Qiu Guofu , Liang Shucai , Teng Hanbing , Wu Lamei , Hu Xianming 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Efficient Electrophilic N‐Amination Utilizing in situ Generated Chloramine under Phase Transfer Conditions.
Authors: Bhattacharya Apurba , Patel Nitin C. , Plata Robert Erik , Peddicord Michael , Ye Qingmei , Parlanti Luca , Palaniswamy Venkatapuram A. , Grosso John A. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereoselective Electrocatalytic Cyclization of 3‐Substituted 2,2‐Dicyanocyclopropane‐1,1‐dicarboxylic Acid Esters to Form 6‐Substituted (1R,5R,6R)*‐4,4‐Dialkoxy‐5‐cyano‐2‐oxo‐3‐azabicyclo [3.1.0]hexane‐1‐carboxylic Acid Esters.
Authors: Elinson M. N. , Fedukovich S. K. , Starikova Z. A. , Vereshchagin A. N. , Belyakov P. A. , Gorbunov S. V. , Nikishin G. I. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regioselective Synthesis of 1‐Aryl‐4‐bromo‐5‐trifluoromethylpyrazoles.
Authors: Nenajdenko V. G. , Reznichenko A. L. , Balenkova E. S. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regioselective Alkylation of 2‐Alkyl‐5,6,7,8‐tetrahydro‐3H‐cycloheptimidazol‐4‐ones and 2‐Alkyl‐3H‐cycloheptimidazol‐4‐ones.
Authors: Sonegawa Motoharu , Yokota Masayuki , Tomiyama Hiroshi , Tomiyama Tsuyoshi 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
5‐Benzylidene‐hydantoins as New EGFR Inhibitors with Antiproliferative Activity.
Authors: Carmi Caterina , Cavazzoni Andrea , Zuliani Valentina , Lodola Alessio , Bordi Fabrizio , Plazzi Pier Vincenzo , Alfieri Roberta R. , Petronini Pier Giorgio , Mor Marco 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Photochromic Properties of 4‐[2‐(Anthracen‐9‐yl)‐5‐methyloxazolyl] Fulgide.
Authors: Rybalkin V. P. , et al. et al. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and in vitro Antimycobacterial Activity of N1‐Nicotinoyl‐3‐(4′‐hydroxy‐3′‐methyl phenyl)‐5‐[(sub)phenyl]‐2‐pyrazolines.
Authors: Shaharyar Mohammad , Siddiqui Anees Ahamed , Ali Mohamed Ashraf , Sriram Dharmarajan , Yogeeswari Perumal 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel Synthesis of 4‐Fluoropyridines Based on 2‐Fluoroallylic Alcohols by Succeeding Ireland—Claisen and Aza‐Cope Rearrangements as Key Steps.
Authors: Wittmann Ulrich , Tranel Frank , Froehlich Roland , Haufe Guenter 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Unusual Reaction of 1,1′‐Dialkyl‐3,3′‐di(2‐quinolyl)‐1,1′,4,4′‐tetrahydro‐4,4′‐biquinolines with Ethyl Chloroformate.
Authors: Kovalev D. A. , Antonova O. A. , Goncharov V. I. , Aksenov A. V. 
Published: October 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.