bluuebunny/crossref_metadata_2025 huggingface dataset:
Poetik des Terrors
Authors: König Michael
Published: February 2015

Religiöse Selbstmordattentäter machen uns sprachlos. Wie aus dem Nichts tauchen sie auf, scheinbar geistesgestörte, selbstherrliche Einzeltäter, die viele mit in den Tod reißen und sich am Ende selbst richten. Kulturelle Erklärungsmuster und biographische Analysen schlagen fehl. Die Frage, wie einer zum Terroristen wird, scheint nicht beantwortbar. Michael König untersucht Romane, Thriller und biographische Erinnerungen, in denen deutsche Gegenwartsautoren versuchen, dem undurchdringlichen Phänomen und seinen Urhebern näher zu kommen. Ergänzend zur literaturwissenschaftlichen Analyse berichten zehn Autorinnen und Autoren - unter ihnen Ulrike Draesner, Sherko Fatah, Gerhard Seyfried, Ulrich Peltzer und Michael Wildenhain - in Interviews über ihre Probleme beim Schreiben über Terroristen und den erzeugten Terror. Sie kennzeichnen ihre eigenen Texte als engagierte Literatur, die im Zuge von weltumspannenden Überwachungsmethoden und einer zunehmenden Beschneidung von Bürgerrechten wieder dezidiert politisch geworden ist. Gegen mediale Generalisierungen rücken sie das Individuum in den Mittelpunkt der literarischen Betrachtung. Denn Attentäter und Terroristen sind am Ende keine »Monster« oder »Gespenster«, sondern Menschen.
Characteristics exponents of the triangular solution in the elliptical restricted three body problem under the radiation and oblateness of primaries
Authors: Narayan Ashutosh , Shrivastava Amit , Ishwar B.
Published: February 2015

This paper studies effects of the oblateness and radiation of both the primaries on the stability of the infinitesimal motion about triangular equilibrium points (L4,5) in the elliptical restricted three body problem (ER3BP) around the binary system We have exploited analytical method for determining of characteristics exponent to the variational equations with periodic coefficients, developed by Bennet (! 965b), which is based on the Floquet's theory. The stability of the infinitesimal motion about the triangular points under the effects of radiation and oblateness of both the primaries around the binary systems Achird, Luyten726-8, Kruger 60, Alpha Centauri AB and Xi Bootis, has been studied. The stability of infinitesimal around the triangular points has been studied based on the analytical and numerical exploration is simulated by drawing transition curves bounding the region of stability in the (Î¼-e) plane. The region of stability changed with variations in eccentricity, oblateness and radiation pressures. It is observed that the equilibrium points stable in the shaded portion of the transition curve, whereas unstable outside the region of the transition curves.
Application of non-associative groupoids to the realization of an open key distribution procedure
Authors: Katyshev Sergey Yu. , Markov Viktor T. , Nechaev Alexander A.
Published: February 2015

We investigate the possibility to use non-associative groupoids in the realization of an open key distribution procedure based on a generalization of the well known Diffie-Hellman algorithm.We prove the existence of non-associative groupoidswhich are simultaneously power commuting and not power-associative.
Asymptotically free action of permutation groups on subsets and multisets
Authors: Sadov Sergey Yu.
Published: February 2015

Let G be a permutation group acting on a finite set Ω of cardinality n. The number of orbits of the induced action of G on the set Ω
Analysis of a discrete semi-Markov model of continuous inventory control with periodic interruptions of consumption
Authors: Shnurkov Petr V. , Ivanov Alexey V.
Published: February 2015

We consider a discrete stochastic model of inventory control based on a controlled semi-Markov process. Probabilistic characteristics of the semi-Markov process are found along with characteristics of a stationary cost functional connected with this process. It is proved that an optimal policy of inventory control is a deterministic one. Explicit analitical representation of stationary functional characterising the control quality is obtained. An optimal control problem is reduced to the solution of an extremal problem for a multivariate function.
N-(4-Arylpiperazinoalkyl)acetamide derivatives of 1,3- and 3,7-dimethyl-1H-purine-2,6(3H,7H)-diones and their 5-HT6, 5-HT7, and D2 receptors affinity
Authors: Żmudzki Paweł , Satała Grzegorz , Chłoń-Rzepa Grażyna , Bojarski Andrzej J. , Popik Piotr , Zajdel Paweł
Published: February 2015

A series of N-(arylpiperazinyl)acetamide derivatives of 1,3- and 3,7-dimethyl-1H-purine-2,6(3H,7H)-dione was synthesized and biologically evaluated in in vitro competition binding experiments for serotonin 5-HT6, 5-HT7, and dopamine D2 receptors. The structure-affinity relationships for this group of compounds allowed for determination of structural features responsible for receptor affinity. Among the investigated derivatives, compounds 5 and 12 with (2,3-dichlorophenyl)piperazine moiety were classified as potent dual 5-HT6/D2 receptors ligands, whereas compound 4, with 4-(benzo[d]isothiazol-3-yl)piperazine moiety, and compounds 8 and 15, with (2,3-dichlorophenyl)piperazine moiety, were classified as potent D2 receptor ligands.
Efficient synthesis of 6-amino-2-thiaspiro[3,3]heptane hydrochloride
Authors: Lu Yan , Wang Jin , Guo Jianyu , Tang Yihong , Zhang Suxia , Tao Jianwei , Xiong Lei , Li Xiujie , Luo Jingyi
Published: February 2015

A novel compound 6-amino-2-thiaspiro[3,3]heptane hydrochloride was synthesized in nine steps using 2,2-bis(bromomethyl)-1,3-propanediol as starting material, with an overall yield of 31%.
Dispersion of Particles in the Emulsion by the Electric Current
Authors: Sizonenko O.N. , Raichenko A.I. , Torpakov A.S. , Derevianko A.V.
Published: February 2015

Possible mechanisms of metal micropowders grinding during high-voltage electric discharge processing in hydrocarbon liquid are considered in the present paper. Conditions for melting of Fe and Ti powder particles in plasma discharge channel and in microplasma channels between particles are found out. Regularities of nanopores movement and electromagnetic particle compression are evaluated. It is shown that the current density in the discharge channel is an important parameter, allowing the assessment of the efficiency of the electrodischarge dispersion of metal particles.
Robust Bayesian Sensitivity Analysis for Case–Control Studies with Uncertain Exposure Misclassification Probabilities
Authors: Mak Timothy Shin Heng , Best Nicky , Rushton Lesley
Published: February 2015

Exposure misclassification in case–control studies leads to bias in odds ratio estimates. There has been considerable interest recently to account for misclassification in estimation so as to adjust for bias as well as more accurately quantify uncertainty. These methods require users to elicit suitable values or prior distributions for the misclassification probabilities. In the event where exposure misclassification is highly uncertain, these methods are of limited use, because the resulting posterior uncertainty intervals tend to be too wide to be informative. Posterior inference also becomes very dependent on the subjectively elicited prior distribution. In this paper, we propose an alternative “robust Bayesian” approach, where instead of eliciting prior distributions for the misclassification probabilities, a feasible region is given. The extrema of posterior inference within the region are sought using an inequality constrained optimization algorithm. This method enables sensitivity analyses to be conducted in a useful way as we do not need to restrict all of our unknown parameters to fixed values, but can instead consider ranges of values at a time.
Bayesian beta regression models
with joint mean and dispersion modeling
Authors: Cepeda-Cuervo Edilberto , Garrido Liliana
Published: February 2015

This paper summarizes some results of beta regression models and proposes
a Bayesian method to fit these models, including joint modeling of the mean and dispersion parameters.
This method is implemented through simulated and applied studies.
The cone method for solving linear systems
Authors: Bereznev Valentin A.
Published: February 2015

A method for determination of a nonnegative solution to a system of linear equations and linear programming problems is proposed in the paper. The method is based on the algorithmic selection of extreme vectors of a convex sharpened polyhedral cone corresponding to those problems.
An extremal shift method for control of HIV infection dynamics
Authors: Bocharov Gennady , Kim Arkady , Krasovskii Andrey , Chereshnev Valery , Glushenkova Vera , Ivanov Alexey
Published: February 2015

Optimal control problems for mathematical models describing HIV infection dynamics in a human body are considered in the paper. An overview of current approaches to solution of control problems for models of HIV dynamics is presented for techniques related to construction of optimal programme (open loop) or positional (feedback) controls for various criteria of control process quality and is based on the Pontryagin’s maximum principle and the Bellman’s theory of dynamic programming, respectively. In the framework of the theory of positional differential games of Krasovskii, there are constructive and efficient methods of synthesis of controls for different classes of dynamical systems. In this paper we present a formalization of a control problem for HIV infection considered as a corresponding positional differential game. The control algorithm based on the method of extremal shift is applied to the ODEs model of HIV infection. The numerical implementation of the extremal shift method is developed to construct the control taking the system to a neighbourhood of a given trajectory using the information on the dynamics of the guides or leaders.
Photochemische Synthese neuer zinnorganischer Verbindungen mit „aktiven“ Gruppen am Zinnatom (I) / Photochemical Synthesis of New Tinorganic Compounds with Active Substituents on Tin
Authors: Leonhardt Thomas , Latscha Hans Peter
Published: February 2015

By photochemically induced oxidative addition reactions the synthesis of some new tinorganic compounds was achieved. The reaction of dichloro-and diiodotin with 1,2-diiodobenzene (1) induced by ultraviolet radiation led to bis-(1-iodophenyl)diiodotin (2), bis-(1-iodophenyl)dichlorotin (3), 1 -iodo-2-(trichlorotin)benzene (4) and 1-iodo-2-(triiodotin)benzene (5). Iodosubstitution at the tin atom was also observed when dichlorotin was used as the starting compound. Analogous experiments with 1,2-dibromobenzene (6) and 1,2-dichloro-(7) gave no products
Über die Kristallstrukturen der Tellurate Pb3Fe2Te2O12 und Pb2CoTeO6 / On the Crystal Structures of the Tellurates Pb3Fe2Te2O12 and Pb2CoTeO6
Authors: Wedel B. , Müller-Buschbaum Hk.
Published: February 2015

Pb3Fe2Te2O12 (I) and Pb2CoTeO6 (II) have been prepared by crystallization from melts. Single crystal X-ray investigations led to monoclinic (I) and tetragonal (II) symmetry, space groups C4
s-Cc and D17
4h-14/mmm. Lattice constants I: a = 9.866(3), b = 15.332(4), c = 7.172(2) Å, β = 111.34(3)°, Z = 4. II: a = 5.661(5), c = 8.004(7) Å, Z = 2. (I) represents a new crystal structure, characterized by a network of octahedra occupied by Fe3+ and Te6+ in a disordered manner. The centres of negative charge of the lone pairs of Pb2+ in I are estimated by Coulomb term calculations. II belongs to the elpasolithe type
Synthese von 1-Butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadien und seiner Natrium-, Thallium(I)-und Eisen(II)-Komplexe / Synthesis of 1-Butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadiene and its Sodium, Thallium (I) and Iron(II) Complexes
Authors: Schumann Herbert , Lentz Alexander
Published: February 2015

1-Butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadiene (3) is prepared starting from 2,3,4,5-tetra-phenylcyclopentadien-1-one which forms 1-butyl-1-hydroxy-2,3,4,5-tetraphenylcyclopentadiene (1) by reaction with BuLi followed by acid hydrolysis. 1 and HBr give 1-bromo-1-butyl-2,3,4,5-tetraphenylcyclopentadiene (2), which in its turn reacts with BuLi and H2O /H+ to yield 3. Treatment of 3 with NaNH2, TlOEt or FeCl2 yields Na[C5Ph4Bu] (4), Tl[C5Ph4Bu] (5) and the corresponding ferrocene Fe[C5Ph4Bu]2 (6), respectively. The 1H and 13C NMR spectra of the new compounds are reported and discussed
1,4-Bis(4-acylphen-1 -yl) 1,3-cy clopentadiene und 1,2,3,4-Tetra(4-alkylphen-1-yl)-1,3-cyclopentadiene und deren Natrium-, Thallium(I)- und Eisen(II)-Komplexe / 1,4-Bis(4-acylphen-1-yl)-1,3-cyclopentadienes and 1,2,3,4-Tetra(4-alkylphen-1-yl)- 1,3-cyclopentadienes and their Sodium, Thallium (I) and Iron(II) Complexes
Authors: Schumann Herbert , Lentz Alexander
Published: February 2015

1,4-Diphenyl-1,3-cyclopentadiene reacts with acyl chlorides RC(O)Cl (R = CH3 (a), C5H11 (c )) to form the corresponding 1,4-bis(4-acylphen-1-yl)-1,3-cyclopentadienes C5 H4 (C6H4 C(O)R)2 (1a, 1c), which upon treatment with NaNH2 or with TlOC2H5 afford the corresponding sodium complexes Na[C5H3 (C6H4C(O)R)2] (2a, 2c) or thallium(I) derivatives Tl[C5H3 (C6H4C(O)R)2] (3a, 3c). The reaction of 1,1′,3,3′-tetraphenylferrocene with CH3C(O)Cl results in the formation of Fe[C5H2 {C(O)CH3} {(C6H4C(O)CH3)2}]- [C5H3 {(C6H4C(O)CH 3)2}] (5), whereas 2c and FeCl2 give Fe[C5H3(C6H4C(O)C5H11)2]2 (4c). The all-para-acylated tetraphenylcyclopentadienes C5H2 (C6H4C(O)R)4 (R = CH3 (a), C3H7 (b)) react with K[N2H4OH] to produce the ligands C5H2(C6H4CH2R)4 (6a, 6b), which undergo reactions with NaNH2 and TlOC2H5 to yield the sodium and thallium(I) salts, Na[C5H2(C6H4CH2R)4] (7a, 7b) and Tl[C5H2(C6H4CH2R)4] (8a, 8b), respectively. 7a and 7b react with FeCl2 to produce the corresponding ferrocenes Fe[C5H(C6H4CH2R)4 ]2 (9a, 9b). The 1H and 13C NMR spectra of the new compounds are reported and discussed
Structural Investigation of Bis(isonitrile)gold(I) Complexes
Authors: Schneider Wolfgang , Sladek Alexander , Bauer Andreas , Angermaier Klaus , Schmidbaur Hubert
Published: February 2015

The reaction of (MeNC)-, (PhNC)- and (MesNC)AuCl in tetrahydrofuran with an equimolar amount of the corresponding isonitrile ligand and one equivalent of Ag+X- (X-= BF-
4 or CF3SO-
3) leads to the formation of the bis(isonitrile)gold(I) complexes (MeNC)2Au+ CF3SO-
3(1), (PhNC)2Au+ BF-
4 (2) and (MesNC)2Au+ BF-
4(3). The crystal structures of 1, 2 and 3 have been determined. In compound 1 there are rod-like cations with a parallel packing into meandering puckered layers, in which the gold atoms have alternating Au-Au contacts of 3.611 and 3.624 Å. In complex 2 the cations form long double-paddles, with the two paddles at an angle of 77.5°. The individual cations are well separated and have no sub-van-der-Waals Au-Au contacts. The crystal structure of 3 is similar, but with a smaller dihedral angle between the planes of the two mesityl rings (56.0°)
Bis-und Tris[μ-nitrido-bis(diorganylphoshinato-O,O′)]- element( 1+)-Kationen / Bis- and Tris[μ-nitrido-bis(diorganylphosphinato-O,O′)]-element(1+) Cations
Authors: Jirjahn Burkhard , Hildebrandt Henry , Heller Gert
Published: February 2015

The following compounds have been prepared and characterized by crystal structure analyses:

Two modifications of bis[μ-nitrido-bis(diphenylphosphinato-O,O′)]boronium (1+) triiodide (A and B): A (monoclinic, P21/c; a = 1908.8, b = 1652.7, and c = 1719.4 pm; β = 109.54°; Z = 4; = 10.3%) and B (triclinic, P 1̄, a = 981.8, b = 1148.9, and c = 2353.7 pm; α = 80,91°, β = 81.09°, γ = 74.58°, Z = 2, wR = 7.4%).

Tris[μ-nitrido-bis(diphenylphosphinato-O,O′)]aluminium( 1 +) triiodide (C) and tris[μ-imidobis(diphenylphosphinato-O,O′)]aluminium (1+)bis(hydrogenphosphate) dioxane adduct (D): C (monoclinic, P21/n ,a = 1332.4, b = 4087.6, an d c = 1368.1 pm; β = 93.17°; Z = 4; R = 10.4%) and D (orthorhombic, Pc21b, a = 1798.7, b = 2151.1, and c = 1948.7 pm; Z = 4; R = 12,8%).

Two modifications of tris[μ-nitrido-bis(diphenylphosphinato-O,O′)]stannium (1+) perchlorate (E and F): E (triclinic, P 1̄, a = 1468.7, b = 1480.2, and c = 1629.8 pm; α = 99.75°, β = 90.77°, and γ = 92,65°, Z = 2, wR = 6,0%) and F (hexagonal, a = 1224 and c = 2110 pm). Bis[μ-nitridobis(diethylphosphinato-O,O′)]boronium (1+) triiodide has been characterized by IR, FIR, 1H - and 31P NMR, as well as by mass spectra
Die Synthese und Kristallstruktur des Borat-Phosphats: α -Zn3(BO3)(PO4) / Synthesis and Crystal Structure of the Borate-Phosphate: α-Zn3(BO3)( PO4)
Authors: Bluhm K. , Park C. H.
Published: February 2015

Single crystals of the compound α -Zn3(BO3)(PO4) were obtained at 1050 °C by using B2O3, P2O5 and ZnCO3 as starting materials and subsequent cooling to 600°C with 20°C/h. X-ray investigations on single crystals yield a new crystal structure in the monoclinic space group Cm - (Nr. 8) with a = 972.5(2); b = 1272.0(3); c = 487.4(3) pm; β = 119.80 (4)°; Z = 4. The structure contains isolated trigonally planar BO3 and tetrahedral PO4 units which are not joined together. Zinc occupies three crystallographically different point positions and is trigonal-bipyramidally, tetragonal-pyramidally or distorted tetrahedrally coordinated by oxygen
Occurrence of Toxin Producing Cyanobacteria in Hungary. Isolation, Separation and Identification of Microcystins
Authors: Habermehl Gerhard G. , Krebs Hans Chr. , Nemes Péter , Nagy Gábor , Scheiber Pál
Published: February 2015

Cyanobacteria (blue-green algae), Microcystis aeruginosa sp., were isolated from a massive bloom in a eutrophic waterbody in Hungary. Their toxic effect, determined by a mouse test, was associated with the occurrence of microcystins YR and LR which were isolated, separated by means of HPLC procedures and identified by mass spectroscopy. The toxin content of the dry cell material is about 0.22 %, indicating a pronounced toxin-producing ability of the species investigated
Optimized Large Scale Synthesis of Phosphorothioate Oligonucleotides on PS-PEG Supports
Authors: Gerster Michael , Maier Martin , Clausen Nils , Schewitz Jens , Bayer Ernst
Published: February 2015

Sulphurization is a crucial step during synthesis of phosphorothioate oligonucleotides. Insufficient reaction leads to inhomogeneous products with phosphodiester defects and subsequently to destabilization of the oligomers in biological media. To achieve a maximum extent of sulphur incorporation, various sulphurizing agents have been investigated. Solely, the use of Beaucage reagent provided satisfactory results on PS-PEG supports. Based on our investigations in small scale synthesis (1 μmol) with continuous-flow technique, upscaling to the 0.1-0.25 mmolar range has been achieved using a peptide synthesizer. The syntheses were performed in batch mode with standard phosphoramidite chemistry. Additionally, large scale synthesis of a phosphodiester oligonucleotide has been carried out on PS-PEG with optimized protocols and compared to small scale synthesis on different supports. Products were analysed by 31P NMR, capillary gel electrophoresis and electrospray mass spectrometry. An extent of sulphurization of 99% and coupling effiencies of more than 99% were obtained and the products proved to have similar purity compared to small scale syntheses on CPG
Darstellung und spektroskopische Charakterisierung von Trifluormethylazosulfonylmethan CH3S(O) 2NNCF3 / Preparation and Spectroscopic Characterization of Trifluoromethylazosulfonylmethan CH3S(O)2NNCF3
Authors: Minkwitz Rolf , Jakob Jens
Published: February 2015

The reaction of trifluoronitrosomethane with CH3S(O)2NH2 and Na2CO3 as a base in THF gi­ves the yellow liquid CH3S(O)2NNCF3, m.p. 18 °C, which was characterized by vibrational and NMR spectra
Structure and Magnetic Properties of a Dinuclear Copper(II) Complex
Authors: Elmali Ayhan , Elerman Yalcin , Svoboda Ingrid , Fuess Hartmut , Griesar Klaus , Haase Wolfgang
Published: February 2015

[Cu2L] (L=N-2-hydroxy-4-methylphenyl-4-oxo-2-pentalketimine) was synthesized and its crystal structure determined. C24H26Cu2N2O4 monoclinic space group P21/n with a= 10.978(2), 17.045(3), c= 11.958(2) Å, β = 101.89(1)°, V = 2189.6(7) Å3,Z = 4. Two copper(II) atoms in a distorted square-planar coordination are bridged by two oxygen atoms to form a dinuclear unit. The copper(II) centers are separated by 3.025(1) Å and antiferromagnetically coupled (J =-222.3 cm-1 ), which follows from temperature-dependent magnetic susceptibility measurements in the range 4.2 to 300 K.
Über die Reaktion von SbPh3 mit S3N2Cl2 Kristallstrukturen von [xxx] und [(Ph3SbCl2)2·S4N4]/ On the Reaction of SbPh3 with S3N2Cl2. Crystal Structures of [xxx] and [(Ph3SbCl2)2· S4N4]
Authors: Kunkel Frank , Harms Klaus , Kang Hak-Chul , Massa Werner , Dehnicke Kurt
Published: February 2015

Triphenylantimony reacts with S3N2Cl2 in dichloromethane solution to give yellow crystals of the cyclostibathiazene derivative [xxx], As a by-product orange single crystals of [(Ph3SbCl2)2·S4N4] were isolated, in which the molecular compounds Ph3SbCl2 and S4N4 only form van der Waals contacts with one another. Both compounds are characterized by crystal structure determinations.

[xxx]: Space group P21/n, Z = 4; lattice dimensions at -80°C: a = 759.4(1), b = 1448.5(3); c = 1557.6(2) pm; β = 91.09(1)°, R = 0.026. The complex has a molecular structure in which the Sb atom is coordinate in a distorted trigonal-bipyramidal fashion with one phenyl group and one of the nitrogen atoms of the planar [xxx] ring in the apical positions.

[(Ph3SbCL)2·S4N4]: Space group C2/c, Z = 8 ; lattice dimensions at -60°C: a = 1549.3(1), b = 1017.7(1), c = 2623.9(1) pm, β = 105.56(2)°, R = 0.050.
2-(Diphenylphosphino)-pyridine as an Ambidentate Ligand in Homo-and Hetero-binuclear Complexes of Copper, Silver, and Gold
Authors: Olmos M. Elena , Schier Annette , Schmidbaur Hubert
Published: February 2015

The reaction of 2-diphenylphosphino-pyridine (1) with AgBF4 in an equimolar ratio affords the cyclic, dinuclear complex 2 with mixed P,N-coordination of the metal atoms. With two equivalents of 1 the 2:1 complexes 4a,b are formed which have the metal atoms solely Pcoordinated. The previously reported gold complex (3), an analogue of 2, or [Au(tht)2]ClO4 (tht = tetrahydrothiophen) also give the 2:1 complexes (5a,b) when treated with an excess of ligand 1. Addition of AgClO4 to a solution of 5a in acetone, or treatment of 4a with [Au(tht)2]ClO4 in dichloromethane, give the same mixed-metal complex 6, where the Au atoms are exclusively P-coordinated, while the Ag atoms are coordinated by the two pyridine nitrogen atoms. In the crystal there are also weak interactions of the perchlorate counterions with the silver atom. Addition of [Cu(MeCN)4]BF4 to compound 5b gives the Cu/Au-complex with P,P-coordinated gold and N,N-bonded copper centers. All products were characterized by standard analytical and spectroscopic techniques; the crystal structure of complex 6 was determined in a single crystal X-ray diffraction study.
Gold(I) Complexes of Open-chain and Cyclic Di-secondary Amines
Authors: López-de-Luzuriaga José M. , Söldner Marcus , Schier Annette , Schmidbaur Hubert
Published: February 2015

Treatment of N,N′-diisopropyl-ethylenediamine or 1,4-piperazine with two equivalents of [(Ph3P)Au]+ BF4
- leads to binuclear complexes of the diamines:

{[(Ph3P)Au]HN(iPro)NCH2-}2
2+ 2 BF4
- (1) and {[(Ph3P)Au]HNCH2CH2}2
2+ 2 BF4
- (2), respectively. In the products each quaternary ammonium center bears one gold ligand, one hydrogen atom and two alkyl substituents. The crystal structures of both compounds have been determined. Compound 1 contains discrete ion-triples. The ethylene bridge in the dications is in an unfolded conformation, with a crystallographic center of inversion, and allows for weak hydrogen bonding N-H--F [2.085 Å; N-H--F 169.2°] between the NH functions and the counterions. The existing distant contacts F--Au [3.599 Å] are probably less significant for the aggregation of the ion triples, but will contribute through Coulomb forces. Compound 2 crystallizes with two solvent molecules CH2CI2. The dication has a crystallographic center of inversion with the piperazine ring in a chair conformation and the gold atoms in equatorial positions. There are hydrogen bonds N-H--F [2.076 and 2.457 Å] between the dication and the anions which lead to the formation of ion-triples, with further contacts between the BF4
- anions and the solvent molecules [C-H--F 2.340 and 2.446 Å].
Photoreactivity of Coordinated Phenylhydrazine. Intraligand Excitation of ReCl(CO)3(PhNH-NH2)2
Authors: Kunkely Horst , Vogler Amd
Published: February 2015

The complex of ReCl(CO)3(PhNH-NH2)2 shows an absorption band at λmax = 272 nm which is assigned to an IL (intraligand) transition of the coordinated phenylhydrazine. Upon IL excitation the complex undergoes a decomposition with ϕ = 0.03 at λirr = 280 nm.
Zinn(IV)-Komplexe mit diaciden Azo(hydrazono)verbindungen. Kristallstruktur von Bis[4-(2′-hydroxyphenylazo)-3-methyl-lphenyl- pyrazol-5-onato(2-)]zinn(IV)/ Tin(IV) Complexes with Diacidic Azo(hydrazono) Compounds. Crystal Structure of Bis[4-(2′-hydroxyphenylazo)-3-methyl-l-phenyl-pyrazol-5-onato(2-)]tin(IV)
Authors: Banße Wolfgang , Jäger Norbert , Ludwig Eberhard , Schilde Uwe , Uhlemann Erhard , Lehmann Andreas , Mehner Hartmut
Published: February 2015

Tin(IV) complexes of diacidic azo and hydrazono compounds were synthesized by the reaction of these ligands with SnCl2acac2 and SnCl2 · 2H2O , respectively. The complexes were further characterized by Mössbauer spectroscopy.

For bis[4-(2′-hydroxyphenylazo)-3-methyl-l-phenyl-pyrazol-5-onato(2-)]tin(IV) force field calculations have been performed and the crystal structure was determined by X-ray analysis.
Synthesen, Kristallstrukturen und Eigenschaften von Trisilber-und Trikalium-tri-μ-imido-cyclotriphosphat, Ag3(PO2NH)3 und K3(PO2NH)3 / Syntheses, Crystal Structures, and Properties of Trisilver and Tripotassium Tri-μ-im ido Cyclotriphosphate, Ag3(PO2NH)3 and K3(PO2NH)3
Authors: Stock N. , Schnick W.
Published: February 2015

Coarse crystalline Ag3(PO2NH)3 (1) and K3(PO2NH)3 (2) are obtained by addition of an aqueous solution of AgNO3 to an acidified solution of Na3(PO2NH)3 · 4H2O and by diffusion controlled addition of ethanol to a solution of K3(PO2NH)3 in water, respectively. The crystal structures of 1 and 2 have been determined by single crystal X-ray methods (Ag3(PO2NH)3: P21/c; a = 1166.6(1), b = 786.4(1), c = 997.8(1) pm, β = 106.91(1)°; Z = 4. K3(PO2NH)3: R3̄; a = 1271.4(2), c = 1017.9(2) pm, Z = 6). In Ag3(PO2NH)3 the cyclic anion is markedly distorted because of interactions between Ag+ and one nitrogen atom of the anion. In K3(PO2NH)3 the trimetaphosphimate ring shows a chair conformation and two cyclic anions are connected to each other by hydrogen bonds. DTA/TG investigations show thermal decomposition above 275 and 250 °C for 1 and 2, respectively.
Zu den Phasenverhältnissen im System V/Nb/O, III Die Koexistenzbeziehungen der Mischkristallreihe V1−x-NbxO2 zu den binären und ternären Phasen der Subsysteme VO2/NbO2/V2O3 und VO2/NbO2/V2O 5/Nb2O5 / The Phase Relations in the System V/Nb/O , III Coexistance Relations of Mixed Crystals V1−x-NbxO2 to the Binary and Ternary Phases of Subsystems VO2/NbO2/V2O3 und VO2/NbO2/V2O 5/Nb2O5
Authors: Woedtke F. von , Kirsten L. , Oppermann H.
Published: February 2015

Mixed crystals V1−XNbXO2 exist about the whole area of quasibinary line VO2-NbO2. The phase relations between these compositions VO2-NbO2 and the binary and ternary phases of the described subsystems were cleared using chemical transport reactions (CTR) and solid state reactions. A more precise phase diagram of the ternary system V/Nb/O is given for the temperature range of 900 - 1000°C.
Reactivity and NMR Spectroscopic Properties of Tri(tert-butyl)plumbyl-amine
Authors: Herberhold Max , Tröbs Volker , Zhou Hong , Wrackmeyer Bernd
Published: February 2015

Tri(tert-butyl)plumbyl-amine 1 was prepared and studied by one- (1D) and two-dimensional (2D) 1H, 13C, 15N and 207Pb NMR which allowed determination of the coupling signs 1J(207Pb,13C) (> 0), 2J(207Pb,13C) (> 0), 1J(207Pb,15N) (> 0; reduced coupling constant 1K(207Pb,I5N) < 0) and 2J(207Pb-N-1H) (< 0). Transamination of 1 with aniline and pyrazole afforded the corresponding aniline (2) and pyrazole derivatives (3), respectively. N-Lithiation of 1, followed by treatment with Me3SiCl gave the tri(tert-butyl)plumbyl-trimethylsilyl-amine 5. The multinuclear magnetic resonance data of 2, 3 and 5 are presented. Trimethylplumbylphenyl- amine and trimethylplumbyl-tert-butyl(dimethyl)silyl-amine were prepared and their NMR data were measured for comparison.
Synthesis, IR and X-Ray Studies of a Dioxouranium(VI) Nitrate Complex with N,N′-Tetraethyl-N″ -trichloracetylphosphortriamide
Authors: Amirkhanov Vladimir M. , Sieler Joachim , Trush Victor A. , Ovchynnikov Vladimir A. , Domasevitch Konstantin V.
Published: February 2015

A new dioxouranium(VI) nitrate complex with N,N′-tetraethyl-N″-trichloracetylphosphortriamide (HL = CCl3C(O)N(H)P(O)(NEt2)2) of composition UO2 (HL)2(NO3)2 (1) has been synthesised. The IR spectroscopic data reveal that the ambidentate ligand is coordinated to the metal center in a monodentate manner via the phosphoryl oxygen atom. The crystal and molecular structure of 1 has been determined from X-ray diffraction data (triclinic, space group P1̄ with a = 9.225(2), b = 10.360(2), c = 12.249(2) Å, α = 100.02 (1), β = 103.81(1), γ = 108.80 (1)°, Z = 1; R = 0.037 for 4092 unique reflections. The structure is made up of centrosymmetric molecules in which the neutral ligands HL are monocoordinated. Phosphoryl and carbonyl groups of the HL moieties are in the trans positions to each other. The axial vertices of the distorted hexagonal bipyramid of uranium are occupied by two oxo ligands [U-O 1.753(5) Å] while six oxygen atoms of phosphoryl and nitrate groups lie in the equatorial plane [U-O 2.347(5)-2.547(6)Å],
Metallkomplexe mit biologisch wichtigen Liganden, XCVI [1] Palladium(II)-, Platin(II)-und Rhodium(I)-Komplexe mit (Phenyl)C-H···Metall-Wechselwirkung von Diphenylmethylen- glycinestern und von 2-Phenyloxazolinonen / Metal Complexes of Biologically Important Ligands, XCVI [1] Palladium(II), Platinum(II) and Rhodium(I) Complexes with (Phenyl)-C-H ··· Metal Interaction of Diphenylmethylene Glycine Esters and from 2-Phenyloxazolones
Authors: Schreiner Bernhard , Prem Markus , Bauer Werner , Polborn Kurt , Beck Wolfgang
Published: February 2015

The reactions of Na2PdCl4, [(nBu3P)PtCl2]2, [(nBu3P)PdCl2]2 and [(C8H14)2RhCl]2/CO with diphenylmethylene glycine esters (L1) or 2-phenyl-4-R-oxazolones (L2) afford the complexes (nBu3P)(Cl)2Pt(L1), (OC)2(Cl)Rh(L1), Cl2Pd(L1)2 and (nBu3P)(Cl)2M(L2) (M = Pd, Pt), respectively. The X-ray structural determination of Cl2Pd(L1)2 and the 1H and 13C NMR spectra show a close proximity of the ortho phenyl-H-atom to the metal; the complexes are precursors for ortho metallation.
Polysulfonylamine, XCVII [1] Di(organosulfonyl)amine und ihre konjugierten Anionen als simultane Baugruppen in zwei supramolekularen Strukturen / Polysulfonylamines, XCVII [1] Di(organosulfonyl)amines and their Conjugate Anions as Simultaneous Building Blocks in Two Supramolecular Structures
Authors: Henschel Dagmar , Wijaya Karna , Moers Oliver , Blaschette Armand , Jones Peter G.
Published: February 2015

The complex compounds 4HN (SO2Me)2 · (diaza-18-crown-6) (1) and Na[N(SO2Ph)2] · 2HN(SO2Ph)2 · 2 (12-crown-4) · 2 MeOH (2) were obtained from their components and characterized by low-temperature X-ray diffraction. Structure 1 (monoclinic, space group P21/n) displays centrosymmetric formula units consisting of a biangular diazonia-18-crown-6 dication, two (MeSO2)2N− anions situated above and below the macrocycle and linked to the NH2
+ groups via an N - H ··· O and N -H ··· N bond system, and finally two HN(SO2Me)2 molecules, each forming an N -H ··· O bond to one of the anions. The molecule-anion entity represents an iso form of the [(RSO2)2N -H ··· N (SO2R)2]− homoconjugates previously described. The crystal packing of 1 is stabilized by an extensive and highly organized [H2C -H ··· O(S)] hydrogen bond network. Structure 2 (monoclinic, space group P21/n) exhibits inconspicuous [Na(12-crown-4)2]+ cations and, as a striking feature, supramolecular anions assembled from a central (PhSO2)2N− ion, two MeOH molecules flanking the amide anion, and two HN (SO2Ph)2 molecules bonded to the MeOH moieties. The assembly is held together by two N -H ··· O(H )(Me) bonds, one MeO -H ··· N− bond and one MeO -H ··· O(anion) interaction. For both structures, conformational peculiarities of the N(SO2C)2 groups are discussed.
The Estenfication of Gibberellins with Dimethylformamide Dimethyl Acetal (DMFDMA)
Authors: Ali Muhammad Shaiq , Hanson James R. , Ahmad Viqar Uddin
Published: February 2015

The key step is to prepare rare gibberellins by converting the more readily available gibberellins (GA3, GA4, GA7 and GA13) into their m ethyl esters. The DMFDMA is employed as an esterifying reagent to avoid the diazom ethane due to its toxic, explosive and hazardous nature. It is observed that DMFDMA apart from esterification can also be used as acetylating and epimerizing reagent.
Regioselektive Cyclisierung von Thiocarbonsäureamiden mit Bisimidoyl- chloriden -Synthese von Thiazolidinen mit einer Ketenacetal-Substruktur / Regioselective Cyclization of Thiocarboxylic Amides with Bisimidoyl Chlorides - Synthesis of Thiadiazolidines Containing a Ketenacetal Substructure
Authors: Beckert Rainer , Gruner Margit
Published: February 2015

The reactions between bisimidoyl chlorides of oxalic acid 1 and different thioamides derived from CH-acidic methylene compounds 2, 7 as well as thiobiuretes 9-11 were investigated. The hitherto unknown cyclic keten-N,S-acetals 3 with an oxalic acid substructure were mainly formed by an ambidoselective cycloacylation reaction. Comparison of 13C NMR data suggests a thiazolidine structure with three exocyclic doubly bound residues. In the case of compound 3 g the exact configuration (Z) was determinated on the basis of a heteronuclear Overhauser experiment.
Notizen: On the Incorporation of Li(I) into the Fluoroapatite Lattice
Authors: Urquiza N. M. , Manca S. G. , Baran E. J.
Published: February 2015

In attempts to incorporate the L i(I) cation into the C a(II) positions of the fluoroapatite lattice it has been shown that the unit cell becomes increasingly distorted with the increase of lithium concentration. Crystallographic data have been obtained from X-ray powder data. The infrared spectra of these substituted apatites show that the Li(I) incorporation has a negligible effect on the strength of the P-O bonds.
Kristallstruktur von Acetat-acidium- hexafluoroantimonat CH3C(OH)2SbF6 Crystal Structure of Acetate Acidium Hexafluoroantimonate CH3C(OH)2SbF6
Authors: Minkwitz Rolf , Hertel Thomas
Published: February 2015

The crystal structure of acetate acidium hexafluoroantimonate CH3C(OH)2
+SbF6
− has been determined on single crystals with MoKα radiation at -83 °C. The structure is triclinic, space group P1̄, Z = 2, and the cell dimensions are a = 604.7(1), b = 692.3(3), c = 951.7(2) pm, α = 102.13(2)°, β = 106.53(2)°, γ = 99.27(2)°. In the CH3C(OH)2
+ cation the C-C distance is 147.8(6) pm , the C -O distances are 125.1(6) and 129.1(5) pm. The SbF6
− anion is slightly distorted octahedral.
Oxotitan-Addukte mit Dimethylsulfoxid: [TiO(OSMe2)5]Cl2 und [Ti4O6(OSMe2)12]Cl4 · 5Me2SO · 1/2 H2O / Oxotitanium Compounds with Dimethylsulfoxide: [TiO(OSMe2)5]Cl2 and [Ti4O6(OSMe2)12]Cl4 · 5Me2SO · 1/2 H2O
Authors: Rabe Susanne , Müller Ulrich
Published: February 2015

While TiCl4 and Na2S4 react in in the presence of PPh4Cl in dichloromethane to yield (PPh4)2[TiSCl4]·2CH2Cl2, we obtained [Ti4O6(OSMe2)12]Cl4·5Me2SO · 1/2H2O (1) from the same reactants in dimethylsulfoxide. Compound 1 is only stable in the presence of dimethylsulfoxide. The crystal structure determination at 153 K shows the presence of cations having an adamantane-like Ti4O6
4+ skeleton with three Me2SO molecules coordinated to each Ti atom via their O atoms. Crystal data: monoclinic, P 21/n, Z = 4, a = 1096.9, b = 3097, c = 2342.7 pm, β = 93.90° (at -120 °C; R = 0.087 % for 4098 reflections). In an attempt to produce the same compound only from TiCl4 and Me2SO, [TiO(OSMe2)5]Cl2 was obtained. Its cation has a rather short Ti=O bond (164.8 pm) and a distorted octahedral coordination of the titanium atom. The crystals are triclinic, P1̄, Z = 2, R = 0.050 for 2063 reflections measured at 153 K.
Kristallstruktur von Bromnitrat BrONO2 / Crystal Structure of Bromine Nitrate BrONO2
Authors: Minkwitz Rolf , Hertel Thomas
Published: February 2015

The crystal structure of bromine nitrate BrONO2 has been determined on a single crystal with MoKα radiation at -83°C. The structure is orthorhombic, space group P212121, Z = 4, and the cell dimensions are a = 403.2(2), b = 684.9(4), c = 1201.4(5) pm. An intermolecular Br.....O contact leads to the formation of chains within the crystal. Attempts to synthesize a bromine(III)-nitrate by oxidizing CF3Br and CF3Br with ClONO2 were not successful.
Prediction of Dissociation Constants of Ammonium Ion in 20 Mass % Ethanol + Water Mixed Solvent Solutions Containing Sodium Chloride
Authors: Maeda Masunobu , Iwata Chisako
Published: February 2015

Dissociation constants of amonium ion (Ka= [H +][NH3]/[NH4+], where [ ] denotes the con­centration) in 20 mass % ethanol + water mixtures with different concentrations of sodium chloride were determined by means of a glass electrode. The dissociation constants in pKa units (on molarity and molality bases) increase linearly with increasing ionic strength. Activ­ity coefficients of ammonia in the ethanol + water mixtures were determined by a transpiration method. The observed dissociation constants on the molality scale were compared with those calculated from the Pitzer equations modified on the basis of the principles of corre­sponding states. The observed values agreed with the calculated ones almost within experi­mental uncertainties.
ab initio MO Optimization of Molecular Structures of Fluoro- and Chloro-Substituted Dibenzo-p-dioxines and the Effect of Halogen Substitution at the 2,3,7,8-Positions on Metabolic Attack
Authors: Weber Roland , Kühn Till , Hagenmaier Hanspaul , Häfelinger Günter
Published: February 2015

Full ab initio optimizations were performed on the molecular structures of 24 fluorinated and chlorinated dibenzodioxines (PFDD/PCDD ) and dibenzofurans (PFDF/PCDF). Reasonable agreement was found by comparing the geometries of four calculated structures with known X-ray data from the literature. For the fluorine substituent, calculated electron densities (Mulliken total charges and π-electron charges) clearly demonstrate the opposite influence of the inductive (I) and mesomeric (M) effect. The changes in π-densities at carbons in ortho-, meta- and para-position are constant for each fluorine substituent (independent of degree, pattern, and position of substitution). It is thus possible to calculate the π-densities of the substituted dioxines by increments starting from dibenzodioxine. π-Charges from quantum mechanical calculations and the increment system show good agreement even for OctaFDD (O8FDD ), where eight substituent effects are acting additively. Compared with fluorine, the chlorine substituent exercises a smaller -I-effect and a clearly weaker +M-effect.

The HOMO coefficients of the unsubstituted dibenzodioxine and dibenzofuran, extracted from ab initio calculations, yield a good explanation for the observed regioselective metabolic attack at the 2,3,7,8-positions. The squares of the HOMO-coefficients of the 2,3,7,8-positions in dibenzodioxine (DD ) are about ten times greater than those of the 1,4,6,9-positions. These HOMO coefficients are practically unaffected by halide substitution. But halogen substitution reduces strongly the electron density at the halogen-bound carbon, which, however, is a necessary prerequisite for the electrophilic oxygen transfer during metabolism. One would therefore expect halogen substitution of dibenzodioxine and dibenzofuran (DF) at the 2,3,7,8-position to hinder metabolism, as is indeed found. This provides a plausible explanation for the highly selective tissue retention of 2,3,7,8-substituted PCDDs and PCDFs.

Our ab initio calculations of five tetra CDDs (T4CDDs) confirm the postulate of Kobayashi et al. [1 ] who, using semiempirical calculations, found a correlation between the toxicity of a dioxine congener and its absolute molecular hardness. The 2,3,7,8-T4CDD also exhibits the smallest absolute hardness (derived from the HOMO-LUMO energy gap) in our calculations.
Metall(II)-Diazin Komplexe: Kristallstrukturen von Cd(pyrazin)Br2, Cd(pyrazin)I2, Cu(pyrazin)Cl2 und Cd(pyrimidin)(NO3)2·2H2O/ Metal(II) Diazine Complexes: Crystal Structures of Cd(pyrazine)Br2, Cd(pyrazine)I2, Cu(pyrazine)Cl2, and Cd(pyrimidine)(NO3)2·2H2O.
Authors: Pickardt Joachim , Staub Benedikt
Published: February 2015

Single crystals of the compounds Cd(pyrazine)Br2, Cd(pyrazine)I2, Cu(pyrazine)Cl2 and Cd(pyrimidine)(NO3)2·2H2O were obtained by crystallisation from aqueous solutions of the metal salts and solutions of the respective diazine in an organic solvent.

The structures of the pyrazine complexes consist of “supramolecular” networks of -M-pyrazine-M-and -M -(μ2-Hal)2-M-chains. The pyrimidine complex shows a three dimensional network due to -M-pyrimidine-M-chains connected via hydrogen bonds between H(H2O) and O(ONO2).
Quaternary Equiatomic Compounds LnZnSbO (Ln = La - Nd, Sm) with ZrCuSiAs-Type Structure
Authors: Wollesen Petra , Kaiser Joachim W. , Jeitschko Wolfgang
Published: February 2015

The five compounds LnZnSbO (Ln = La - Nd, Sm) were prepared by annealing cold-pressed pellets of the lanthanoids, zinc oxide, and antimony, or by reacting these components in a NaCl/KCl flux. They crystallize with the tetragonal ZrCuSiAs type structure, which was refined from single-crystal X-ray data of CeZnSbO : P 4/nmm, a = 419.76(4), c = 947.4(1) pm, Z = 2, R = 0.022 for 165 structure factors and 12 variable parameters. Chemical bonding in this and the formally isotypic compound CeZn1-xSb2 is briefly discussed.
Synthesis and Mesomorphic Properties of Azo Compounds Derived from Phenyl-and Thienyl-1,3,4-Thiadiazole
Authors: Parra M. , Villouta Sh. , Vera V. , Belmar J. , Zúñiga C. , Zunza H.
Published: February 2015

The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4- thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the higher homologues (n = 9 - 10) also show a monotropic smectic C phase. Series 5b show dimorphism SC - N (for n = 5 - 7 the SC is monotropic). These series are compared with the Schiff’s bases analogues, the imine bond gives rise to similar liquid crystals phase but larger mesomorphic range.
Notizen: C4S8
2- and C16S18
4-: Intermediates in the Synthesis of PoIy(Carbon Sulfide)
Authors: Chou Jun-Hong , Rauchfuss Thomas B.
Published: February 2015

(PPN)2C16S18 was obtained by the addition of PPN+Cl- to a methanolic extract of Na2C4Sx, derived from the reaction of C6S8O2 and NaOMe. Centrosymmetric C16S18
4- consists of thiophene units unsymmetrically fused to two 1,4-dithiin rings. Solutions of C16S18
4- convert to C8S8
2- with heating. When C4Sx (x ~ 8) is reduced by Na/NH3 followed by extraction and crystallization, one obtains the bicyclic polysulfide C4S8
2-, crystallized as its PPh4
+ salt.
Flavonoids and Terpenoids from Luma gayana (Barn.) Burret
Authors: Wächter Gerald A. , Wangmaneerat Aree , Caple Kay M. , Montenegro Gloria , Timmermann Barbara N.
Published: February 2015

The flavonoids 5-hydroxy-7-methoxyflavanone, 6,8 -dimethyl- 5,7-dihydroxyflavanone and 2′,4′-dihydroxy-6′- methoxy-3′,5′-dimethylchalcone, a mixture of alkyl esters of p-coumaric acid, the triterpenoids oleanolic acid and maslinic acid, the monoterpenoid 1α,2β,4β-trihydroxy- p-menthane, the sesquiterpenoid clovandiol and β-sitosterol were isolated from the aerial parts of Luma gayana (Barn.) Burret. This is the first report on the chemistry of this species.
ʟ-Ovothiol A: The Egg Release Pheromone of the Marine Polychaete Platynereis Dumerilii: Annelida: Polychaeta
Authors: Röhl Ingo , Schneider Bernd , Schmidt Bettina , Zeeck Erich
Published: February 2015

Sex pheromones, released with the coelomic fluid by male Platynereis dumerilii initiate egg release in swarming females. The egg release pheromone, isolated from the coelomic fluid of sexually mature males, was identified as ʟ-Ovothiol A, which was found in male marine invertebrates for the first time. Isolation was obtained by reversed-phase high-performance liquid chromatography in the biologically inactive disulfide form.
Prenylated Bibenzyls from the Liverwort Radula laxiramea
Authors: Cullmann Frank , Becker Hans
Published: February 2015

From Radula laxiramea, 12 bibenzyl derivatives and the common bisbibenzyl perrottetin E were isolated. Two compounds are described for the first time as natural products, and one, previously only known after derivatisation, was found in genuine form . Perrottetinene, a cannabinoid from a liverwort is worth mentioning.
Sesquiterpenoids from the Liverwort Porella canariensis
Authors: Cullmann Frank , Becker Hans
Published: February 2015

From the liverwort Porella canariensis, collected in Madeira, Portugal, nine pinguisanes, four drimanes, including the pungent polygodial, two germacranes, and two aromadendranes were isolated. The major compounds were the arom adendrane ent-cyclocolorenone and the nor-pinguisane norpinguisone. Three hydrocarbons were isolated by low temperature column chrom atography. One germacrane and one pinguisane proved to be new natural products.
A Pyoverdin from the Antarctica Strain 51W of Pseudomonas fluorescens
Authors: Voss Jessica , Taraz Kambiz , Budzikiewicz Herbert
Published: February 2015

From the strain 51W of Pseudomonas fluorescens living under extreme conditions at the Schirmacher Oasis (Antarctica) a pyoverdin was obtained. Its structure was elucidated by chemical degradation and spectroscopic methods. The NMR data of the pyoverdin and of its Ga(III) complex were compared. Appreciable influences of the metal on the chemical shifts of the atoms at its binding sites were observed. Thus the structural elements involved in the complexation can be identified and coinciding signals of amino acids occurring more than once in the peptide chain can be separated.
Purification and Characterization of a β-Glucosidase Specific for 2,4-Dihydroxy- 7-methoxy-1,4-benzoxazin-3-one (DIMBOA) Glucoside in Maize
Authors: Oikawa Akira , Ebisui Kenkichi , Sue Masayuki , Ishihara Atsushi , Iwamura Hajime
Published: February 2015

Occurrence and properties of hydroxamic acid glucoside glucosidase were investigated in 10-day-old, autotrophic maize (Zea mays L.) in which 2,4-dihydroxy-7-methoxy-1,4- benzoxazin-3-one glucoside (DIMBOA-G) is a major benzoxazinone component. Crude extracts of both leaves and roots showed glucosidase activity for both DIMBOA-G and 2,4- dihydroxy-1,4-benzoxazin-3-one glucoside (DIBOA-G). A cation-exchange chromatography after cryoprecipitation of the extract from leaves gave a peak with both activities, and further purification by ion-exchange and hydroxyapatite chromatography gave a fraction with an apparent homogeneity, the purification being 560 fold. The Km values (mᴍ) of the purified glucosidase were 0.16 for DIMBOA-G, 0.68 for DIBOA-G and 2.96 for p-nitrophenyl-β-ᴅ-glucopyranoside. The activity on salicin and esculin was too low to be detected. The data indicate that a glucosidase specific for DIMBOA-G comes into contact with constitutive benzoxazinone glucosides producing defensive aglycone when plants are damaged by microbial or insect attacks.