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  • Inorganic Chemistry  (5)
  • Polymer and Materials Science  (3)
  • H/D exchange  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Topographie der Cyclodextrin-Einschlußverbindungen, VIIVI. Mitteil.:W. Saenger, K. Beyer und P. C. Manor, Acta Crystallogr., im Durck (1975). Entnommen aus der Diplomarbeit M. Noltemeyer, Institut für Organische Chemie der Universität Göttingen und Max-Planck-Institut für Experimentalle Medizin, Göttingen 1974. Kurzmitteil.: W. Saenger und M. Noltemeyer, Angew. Chem. 86, 594 (1974). Angew. Chem., Int. Ed. Engl. 13, 552(1974).. Röntgenstrukturanalyse des α-Cyclodextrin. Krypton-Pentahydrats. Zum Einschlußmechanismus des Modell-Enzyms (1976)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 503-517 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Topography of Cyclodextrin Inclusion Complexes, VII* X-Ray Analysis of α-Cyclodextrin. Krypton Pentahydrate. On the Inclusion Mechanism of the Model EnzymeWhen crystallized from water under krypton pressures of 43 PSI (A) and 200 PSI(B), α-cyclodextrin (α-CD) yields inclusion compounds of composition α-CD·(0.78 H2O, 0.48 Kr)·5H2O (A) and α-CD·(0.28 H2O, 0.74 Kr)·5H2O (B). Both the adducts are isomorphous, space group P212121. The structures were determined from about 3900 X-ray data and refined to an R-factor of 8.8%. Although Kr has nearly the same van der Waals diameter as H2O (4Å), the structures of the Kr and of the recently determined α-CD·2H2O adduct are different. In the latter, the 5.0 Å wide cavity of α-CD is diminished by rotation of two glucoses, rendering the α-CD conformation strained. in the almost hexagonal Kr-adduct, all six glucoses are approximately equivalent, the cavity is 5 Å in diameter and the Kr is statistically disordered over five positions. It is concluded that α-CD adducts are stabilized through release of conformation- and hydrogen bonding energy when the “empty” α-CD·2H2O adduct transforms into any other adduct. This mechanism explains why so many different guest molecules are enclosed and bears some relation to enzyme-substrate interactions.
    Notes: α-Cyclodextrin (α-CD) liefert aus Wasser in Gegenwart von Krypton bei 3 und 14 atü kristalline Einschlußverbindungen der Zusammensetzung α-CD·(0.78H2O, 0.48 Kr)·5 H2O (A) und α CD·(0.28 H2O, 0.74 Kr)·5H2O (B). Beide sind isomorph, Raumgruppe P212121. Die Strukturen wurden aus etwa 3900 Röntgenreflexen gelöst und bis zu einem R-Faktor von 8.8% verfeinert. Obwohl Kr mit 4 Å van der Waals- Durchmesser etwa ebenso groß ist wie H2O3, sind die Strukturen der Kr-Addukte von der des reinen αCD·2H2O-Adduktes verschieden. Der 5.0 Å große Hohlraum im α-CD wird im H2O-Addukt durch Rotation zweier gegenüberliegender Glucosen zusammengezogen und dadurch gespannt. Im beinahe hexagonalen Kr-Addukt sind alle sechs Glucosen annähernd gleichwertig und das Kr besetzt statistisch fünf verschiedene Lagen, um den 5.0 Å weiten Innenraum auszufüllen. Es wird gefolgert, daß beim Austausch des Wassers gegen Gastmoleküle frei werdende Konformations- und Wasserstoffbrückenenergie die Addukte stabilisiert. Dieser Mechanismus erklärt, weshalb viele Gastmoleküle mit so unterschiedlichen Eigenschaften eingeschlossen werden und wird im Zusammenhang mit der Enzym-Substrat-Wechselwirkung diskutiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19761090214
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  • 2
    Electronic Resource
    Electronic Resource
    Winkelung eines aromatischen Systems durch den sterischen Effekt eines rotationsgehemmten Substituenten: Molekül- und Kristallstruktur von 3-Diisopropylamino-benzisothiazol-1.1-dioxid (1969)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 102 (1969), S. 1468-1479 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wie mit dreidimensionalen Röntgendaten gezeigt wird, kristallisiert 3-Diisopropylamino-benzisothiazol-1.1-dioxid in der orthorhombischen Raumgruppe Pbca mit der Elementarzelle a = 14.139 Å, b = 11.064 Å, c = 17.405 Å. Die Bestimmung der Lage des Schwefelatoms aus der Patterson-Funktion war zweideutig, da dieses Atom auf der c-Gleitebene liegt, Beide Lösungen führten zu sinnvollen Strukturen, von denen aber nur eine zu R = 0.046 verfeinert werden konnte. Die Substituenten um den Aminostickstoff sind planar angeordnet und bilden einen Winkel von 14°4′ mit der Isothiazolebene. In dem Bestreben, volle Mesomerie zu erreichen, suchen die Atome des Moleküls sich eben anzuordnen, wobei die zum Aromaten „endo-ständige“ Isopropylgruppe einen Druck auf den Benzolring ausübt, diesen staucht und um 6°4′ von der Isothiazolebene wegdrückt: das aromatische System ist gewinkelt.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19691020505
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  • 3
    Electronic Resource
    Electronic Resource
    Kristall- und Molekülstruktur des 4-Methyl-1,3,2-dioxa-phosphorinan-2-oxids, Eine P—H … O-Wasserstoffbrückenbindung (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 3519-3523 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 4-Methyl-1,3,2-dioxaphosphorinane 2-Oxide, A P—H…O Hydrogen Bond4-Methyl-1,3,2-dioxaphosphorinane 2-oxide crystallized in space group P212121 with a = 10.442 (3) Å, b = 9.293 (3) Å, c = 6.633 (3) Å. The structure was elucidated from 459 X-ray diffractometer data and refined to a conventional R-factor R = 5.5%. The exocyclic substituents are in equatorial position. The angles between the ester O — P bonds (105.7°) are smaller than the angles between ester O — P bonds and the P = O double bond (112.6° and 113.1°). The hydrogen atom attached to the phosphorus atom is involved in a P—H…O hydrogen bond with distances P—H, 1.39 Å, P…O, 3.56 Å, H…O, 2.26 Å, and an H—P…O angle of 16°.
    Notes: 4-Methyl-1,3,2-dioxaphosphorinan-2-oxid kristallisierte in Raumgruppe P212121 mit a = 10.442 (3) Å, b = 9.293 (3) Å, c = 6.633 (3) Ä. Die Struktur wurde aus 459 Diffraktometerdaten bestimmt und zu einem konventionellen R-Faktor von 5.5% verfeinert. Die exocyclischen Substituenten sind in äquatorialer Position. Die Winkel zwischen den Ester-O—P-Bindungen (105.7°), sind kleiner als die Winkel zwischen Ester-O—P-Bindung und P = O-Doppelbindung (112.6° und 113.1°). Das am Phosphoratom gebundene Wasserstoffatom bildet eine P—H…O-Wasserstoffbrückenbindung, mit den Abständen P—H, 1.39 Å, p…O, 3.56 Å, H…O, 2.26 Å, und einem H—P…O-Winkel von 16°.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731061107
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  • 4
    Electronic Resource
    Electronic Resource
    Die Molekül- und Kristallstruktur des exo-Bicyclo[2.1.0]pentyltosylats (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 2883-2889 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular and Crystal Structure of exo-Bicyclo[2.1.0]pentyl Tosylateexo-Bicyclo[2.1.0]pentyl tosylate crystallizes from petrol ether in the triclinic space group PĪ with unit cell constants a = 9.952 Å, b = 6.235 Å, c = 9.657 Å, α = 89.67°, β = 98.81°, γ = 90.85°. The atomic parameters were derived from 1187 diffractometer measured X-ray data and refined to a disagreement index R = 6.4%. Within the molecule, the normals to the cyclobutane and cyclopropane rings are at an angle of 112.5° to each other, the bridge C-C bond, 1.525 Å, is of „normal“ length. The unusual behaviour of the molecule towards solvolysis is due to a stabilization of the transition state through the substitution of an oxygen atom at C(5) rather than to a destabilization of the ground state.
    Notes: exo-Bicyclo[2.1.0]pent-5-yltosylat (1) kristallisiert aus Petroläther in der triklinen Raumgruppe P mit den Zellkonstanten a = 9.952 Å, b = 6.235 Å, c = 9.657 Å, α = 89.67°, β = 98.81°, γ = 90.85°. Die Atomparameter wurden aus 1187 Röntgenreflexintensitäten ermittelt und zu einem Diskrepanzindex R = 6.4% verfeinert. In dem Molekül bilden die Normalen auf die Cyclobutan- und Cyclopropanringe einen Winkel von 112.5°, die Brückenbindung ist mit 1.525 Å „normal“ lang. Damit ist das ungewöhnliche Solvolyseverhalten mit einer Stabilisierung des Übergangszustandes durch die Sauerstoffsubstitution am C(5) zu erklären, nicht aber mit einer Destabilisierung des Grundzustandes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060917
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  • 5
    Electronic Resource
    Electronic Resource
    Kristall- und Molekülstruktur von 4-Amino-1-methyl-2-(methylthio)pyrimidinium-chlorid  -  Ein Modell für S-alkyliertes 2-Thiocytidin (1977)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 353-360 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 4-Amino-1-methyl-2-(methylthio)pyrimidinium Chloride - A Model for S-Alkylated 2-ThiocytidineCrystals of 4-amino-1-methyl-2-(methylthio)pyrimidinium chloride (3) are triclinic, space group P1, with two molecules in the asymmetric unit. The structure was solved by direct methods and refined to R = 0.054. The molecules are planar with the S-methyl group in a cis-relationship with the C(2)-N(3)-bond. Bond lengths and angles for the two molecules are equal within standard error limits, and indicate largely aromatic structures. In the crystal matrix, one of the two chloride ions in the asymmetric unit forms three hydrogen-bonds, the other only one.
    Notes: 4-Amino-1-methyl-2-(methylthio)pyrimidinium-chlorid (3) kristallisiert in der triklinen Raumgruppe P1 mit zwei Molekülen in der asymmetrischen Einheit. Die Lösung der Struktur durch direkte Methoden führte nach Verfeinerung zu einem R-Faktor von 0.054. Die Moleküle sind planar mit den S-Methyl-Gruppen in cis-Stellung zur C(2)-N(3)-Bindung. Bindungsabstände und -winkel der beiden Moleküle sind innerhalb der Standardabweichungen gleich und deuten auf weitgehend aromatische Konstitutionen. Im Kristallgitter bildet eines der beiden Chlorid-Ionen in der asymmetrischen Einheit drei, das andere dagegen nur eine Wasserstoffbrücken-bindung aus.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19771100137
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  • 6
    Electronic Resource
    Electronic Resource
    The structure of the left-handed antiparallel amylose double helix: Theoretical studies (1993)
    New York : Wiley-Blackwell
    Biopolymers 33 (1993), S. 363-375 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The atomic coordinates from the crystal structure of a hexasaccharide complex accommodating a zigzag polyiodide [ W. Hinrichs, G. Büttner, M. Steifa, Ch. Betzel, V. Zabel, B. Pfannemüller, and W. Saenger (1987) Science Vol. 238, pp. 205-208; W. Hinrichs and W. Saenger (1990) Journal of the American Chemical Society, Vol. 112, pp. 2789-2796 ] served to construct an antiparallel-stranded amylose double helix with a 5 Å wide central cavity. Using our methodology for the energetic optimization of polymer structures in the internal/ helical variable space [ H. Sklenar, R. Lavery, and B. Pullman (1986) Journal of Biomolecular Structure Dynamics, Vol. 3, pp. 967-987, 989-1014; 1015-1031], we have calculated a theoretical counterpart of this idealized double helix by constraining the helical twist and rise to their experimental values (-45° and 2.33 Å, respectively). Applying the same constraints to the parallel-stranded duplex, this also leads to a low-energy structure with wide central cavity. It is considered as an alternative model to accommodate iodine as observed in the starch-iodine complex.Release of the helical constraints leads to left-handed antiparallel- and parallel-stranded double helices, respectively, with narrow central cavities. Both structures have very similar helix parameters and correspond, in their main characteristics, to the experimentally derived parallel-stranded structure of amylose in starch (6 residues per turn and a pitch height of about 21 Å). The intramolecular energy calculated for the optimized antiparallel-stranded amylose double helix is comparable to that of the parallel-stranded structure. This result raises the question why parallel-stranded amylose seems to be favored in nature. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360330305
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  • 7
    Electronic Resource
    Electronic Resource
    Theoretical drug design: 6-Azauridine-5′-phosphate - its X-ray crystal structure, potential energy maps, and mechanism of inhibition of orotidine-5′-phosphate decarboxylase (1979)
    New York : Wiley-Blackwell
    Biopolymers 18 (1979), S. 2015-2036 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cytostatic drug 6-azauridine is converted in vivo to 6-azauridine-5′-phosphate (z6Urd-5′-P), which blocks the enzyme orotidine-5′-phosphate decarboxylase (Ord-5′-Pdecase) and therefore inhibits the de novo production of uridine-5′-phosphate (Urd-5′-P). In order to relate the structure and function of z6Urd-5′-P, it was crystallized as trihydrate, space group P212121 with a = 20.615 Å, b = 6.265 Å, c = 11.881 Å, and the structure established by Patterson methods. Atomic parameters were refined by full-matrix least-squares methods to R = 0.066 using 1638 counter measured x-ray data. The ribose of z6Urd-5′-P is in a twisted C(2′)-exo, C(3′)endo conformation, the heterocycle is in extreme anti position with angle N(6)-N(1)-C(1′)-O(4′) at 86.3°, and the orientation about the C(4′)-C(5′) bond is gauche, trans in contrast to gauche, gauche found for all the other 5′-ribonucleotides. Conformational energy calculations show that z6Urd-5′-P may adopt an extreme anti conformation not allowed to Urd-5′-P, and they also predict the same unusual trans, gauche conformation about the C(4′)-C(5′) bond in orotidine-5′-phosphate (Ord-5′-P) and in z6Urd-5′-P, which renders the distances O(2)…O(5′) in z6Urd-5′-P and O(7)…O(5′) in Ord-5′-P comparable. On this basis the function of z6Urd-5′-P as an Ord-5′-Pdecase inhibitor can be explained as being due to its structural similarity with the substrate Ord-5′-P and further clarifies the inhibitory action of 5′-nucleotides bearing the heterocycles oxipurinol, xanthine, or allopurinol [J. A. Fyfe, R. L. Miller, and T. A. Krenitsky, J. Biol. Chem. 248, 3801 (1973)]. With this in mind, new inhibitors for Ord-5′-Pdecase may be designed.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1979.360180814
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  • 8
    Electronic Resource
    Electronic Resource
    Self-association of bovine pancreatic trypsin inhibitor: Specific or nonspecific? (1991)
    New York : Wiley-Blackwell
    Biopolymers 31 (1991), S. 1347-1349 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360311112
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  • 9
    Electronic Resource
    Electronic Resource
    Rapid Water Diffusion in a Cage-Type Crystal Lattice: β-Cyclodextrin DodecahydrateThis study was supported by the Deutsche Forschungsgemeinschaft (Sa 196/25-1), the Fonds der Chemischen Industrie, the Deutscher Akademischer Austauschdienst (322-inida-dr), and the Junta Nacional de Investigação Científicae Tecnológica (Lisboa). T. S. is on leave from Max-Delbrück-Centrum für Molekulare Medizin, Forschungsgruppe Kristallographie, Robert-Rössle-Strasse 10, D-13122 Berlin (Germany). (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 34 (1995), S. 1452-1453 
    Details
    ISSN: 0570-0833
    Keywords: cyclodextrins ; diffusion ; H/D exchange ; Raman spectroscopy ; solid-state structures ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.199514521
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