bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rat lens aldose reductase inhibitory constituents of Nelumbo nucifera stamens
Authors: Lim Soon Sung , Jung Yu Jung , Hyun Sook Kyung , Lee Yeon Sil , Choi Jae Sue 
Published: August 2006

AbstractAldose reductase, the principal enzyme of the polyol pathway, has been shown to play an important role in the complications associated with diabetes. A methanol extract of the stamens of Nelumbo nucifera Gaertn. was shown to exert an inhibitory effect on rat lens aldose reductase (RLAR), and thus was fractionated using several organic solvents, including dichloromethane, ethyl acetate and n‐butanol. The ethyl acetate‐soluble fraction, which manifested potent RLAR‐inhibitory properties, was then purified further via repeated measures of silica gel and Sephadex LH‐20 column chromatography. Thirteen flavonoids: kaempferol (1) and seven of its glycosides (2–9), myricetin 3′,5′‐dimethylether 3‐O‐β‐d‐glucopyranoside (10), quercetin 3‐O‐β‐d‐glucopyranoside (11) and two isorhamnetin glycosides (12, 13) were isolated from N. nucifera, as well as four non‐flavonoid compounds: adenine (14), myo‐inositol (15), arbutin (16) and β‐sitosterol glucopyranoside (17). These compounds were all assessed with regard to their RLAR‐inhibitory properties. Among the isolated flavonoids, those harboring 3‐O‐α‐l‐rhamnopyranosyl‐(1→6)‐β‐d‐glucopyranoside groups in their C rings, including kaempferol 3‐O‐α‐l‐rhamnopyranosyl‐(1→6)‐β‐d‐glucopyranoside (5) and isorhamnetin 3‐O‐α‐l‐rhamnopyranosyl‐(1→6)‐β‐d‐glucopyranoside (13), were determined to exhibit the highest degree of rat lens aldose reductase inhibitory activity in vitro, evidencing IC50 values (concentration required for a 50% inhibition of enzyme activity) of 5.6 and 9.0 µm, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Identification and reduction of ion suppression effects on pharmacokinetic parameters by polyethylene glycol 400
Authors: Weaver Richard , Riley Rob J. 
Published: August 2006

AbstractIon suppression in mass spectrometry has been described recently in detail and should always be considered during analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS) in a drug metabolism and pharmacokinetics (DMPK) environment. At best, ion suppression leads to decreased sensitivity but at worst could lead to incorrectly determined pharmacokinetic (PK) parameters. Our investigations centred on polyethylene glycol (PEG 400), an excipient often used in pre‐clinical dosing vehicles. PEG was also found to be present in large quantities in the blood collection tubes used for pre‐clinical PK studies. Ion suppression was observed for many analytes, either due to the use of PEG in the dosing vehicle or in blood collection tubes. The elimination of large ion suppression effects was attained by simple chromatographic gradient changes and the use of alternative blood collection tubes. The effect of the above was to increase the detected plasma concentration levels, which resulted in a change in key PK parameters. Copyright © 2006 John Wiley & Sons, Ltd.
High‐throughput screening for multi‐class veterinary drug residues in animal muscle using liquid chromatography/tandem mass spectrometry with on‐line solid‐phase extraction
Authors: Tang Hubert Po‐on , Ho Clare , Lai Shirley Sau‐ling 
Published: August 2006

AbstractA rapid qualitative method using on‐line column‐switching liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed and validated for screening 13 target veterinary drugs: four macrolides – erythromycin A, josamycin (leucomycin A3), kitasamycin (leucomycin A5), and tylosin A; six (fluoro)quinolones – ciprofloxacin, danofloxacin, enrofloxacin, flumequine, oxolinic acid, and sarafloxacin; and lincomycin, virginiamycin M1, and trimethoprim in different animal muscles. Clindamycin, norfloxacin, nalidixic acid, oleandomycin, ormetoprim, and roxithromycin were used as the internal standards. After simple deproteination and analyte extraction of muscle samples using acetonitrile, the supernatant was subjected to on‐line cleanup and direct analysis by LC/MS/MS. On‐line cleanup with an extraction cartridge packed with hydrophilic‐hydrophobic polymer sorbent followed by fast LC using a short C18 column resulted in a total analysis cycle of 6 min for 19 drugs. This screening method considerably reduced the time and the cost for the quantitative and confirmatory analyses. The application of a control point approach was also introduced and explained. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of nicotine in mainstream smoke on the single puff level by liquid‐phase microextraction coupled to matrix‐assisted laser desorption/ionization Fourier transform mass spectrometry
Authors: Xie Jian‐Ping , Sun Shi‐Hao , Wang Hao‐Yang , Zong Yong‐Li , Nie Cong , Guo Yin‐Long 
Published: August 2006

AbstractA method coupling liquid‐phase microextraction with matrix‐assisted laser desorption/ionization Fourier transform mass spectrometry (LPME/MALDI‐FTMS) was developed to measure the content of nicotine in mainstream smoke at the single puff level. Glycerol was utilized as a matrix additive in the sample preparation to improve the homogeneity of analyte distribution in a sample spot. Good repeatability of the MALDI‐MS signal (RSD <9%) was achieved by the method. Selective LPME facilitated the separation and purification of basic components from cigarette smoke. The LPME device was coupled to a smoking machine, and each puff of one cigarette could be gathered by this modified machine. The amount of nicotine in the mainstream smoke was measured at the single puff level by LPME/MALDI‐FTMS. The method was simple and selective and was sufficiently sensitive to detect nicotine in each puff of one cigarette. The method thus offered an alternative approach to the study of the formation mechanism of cigarette smoke constituents. Copyright © 2006 John Wiley & Sons, Ltd.
Market value effects of acquisitions involving internet firms: a resource‐based analysis
Authors: Uhlenbruck Klaus , Hitt Michael A. , Semadeni Matthew 
Published: August 2006

AbstractWhile most prior research suggests that the average change in market value of acquiring firms varies closely around zero, recent research grounded in the resource‐based view and organizational learning theory identify positive returns to acquirers. We contribute to this literature by focusing on acquisitions of Internet firms and the potential for the transfer of scarce resources. We hypothesize that acquisitions made by offline firms of Internet firms and by Internet firms of other Internet firms lead to positive market valuation for the acquirer. Results of an event study of 798 acquisitions of Internet firms provided support for these predictions. We also find that prior alliances with online firms do not reduce the gains from such acquisitions to offline firms. Copyright © 2006 John Wiley & Sons, Ltd.
Molecular Cage, One‐Dimensional Tube and Two‐Dimensional Polycatenane obtained from Reactions of Flexible Tripodal Ligand 1,3,5‐Tris(imidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene with Copper Salts
Authors: Meng Wen‐Li , Fan Jian , Okamura Taka‐aki , Kawaguchi Hiroyuki , Lv Yang , Sun Wei‐Yin , Ueyama Norikazu 
Published: August 2006

AbstractThree novel copper complexes, [CuII(titmb)(N3)2]·0.5H2O (1), [CuI3(titmb)2](ClO4)3 (2), and [CuII(titmb)(SO4)]·2.2H2O (3), were obtained by reactions of flexible tripodal ligand 1,3,5‐tris(imidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene (titmb) with the corresponding copper(II) salts using hydrothermal method and their structures were determined by X‐ray crystallography. Complex 1 exhibits a one‐dimensional (1D) tube‐like chain structure, while the 2 possesses a M3L2 molecular cage‐like structure, in which the copper atom has a valence of +1, indicating that the CuII is reduced to CuI under the hydrothermal condition. Complex 3 has a polycatenated network structure with inclined interpenetration of (6,3) networks. Ligand titmb adopts a cis,cis,cis‐conformation in all of the three complexes. The results indicate that the anions play important roles in the structure of the complexes. In addition, complex 2 was further investigated by electrospray massspectrometry.
Funktionelle Zinkkomplexe mit einem p‐Nitrophenyl‐substituierten TREN‐Liganden
Authors: Calvo José A. Maldonado , Vahrenkamp Heinrich 
Published: August 2006

AbstractFunctional Zinc Complexes of a p‐Nitrophenyl Substituted TREN‐LigandThe new ligand tris{2‐[(p‐nitrophenylmethyl)amino]ethyl}amine (L) was synthesized from tris(2‐aminoethyl)amine (TREN) and p‐nitrobenzaldehyde. With zinc halides it forms the complexes [L·ZnCl]Cl and [L·ZnBr]Br. Its reactions with zinc nitrate and zinc perchlorate yield the aqua complexes [L·Zn(OH2)](NO3)2 and [L·Zn(OH2)](ClO4)2. One equivalent of KOH converts the latter in situ to the hydroxido complex [L·Zn‐OH]+. This picks up CO2 from the atmosphere producing the dinuclear carbonato complexes [L·Zn‐O‐CO‐O‐Zn·L]X2, with X = nitrate or perchlorate. This CO2 uptake is inhibited, just like in the enzyme carbonic anhydrase, by thiocyanate, resulting in the thiocyanato complex [L·Zn‐NCS]ClO4. The structures of the chloro, aqua, and carbonato complexes were determined.
Ba11In6O3: Ein Indid‐Oxid mit neuartigen [In6]‐Baugruppen
Authors: Wendorff Marco , Röhr Caroline 
Published: August 2006

AbstractBa11In6O3: An Indide Oxide with Novel [In6] Building UnitsThe indide oxide Ba11In6O3 was synthesized from stoichiometric amounts of the elements starting from barium and indium in combination with barium oxide or barium peroxide respectively at a maximum temperature of 850 °C. Its crystal structure was solved and refined from single crystal diffractometer data. The title compound crystallizes with a new structure type (tetragonal, space group I4/mcm, a = 1555.8(3), c = 1121.6(2) pm, Z = 4, R1 = 0.0265) and exhibits planar [In6] anions besides oxide ions coordinated by Ba cations in an octahedral arrangement. The [OBa6] octahedra are connected via corners to form a three‐dimensional network closely related to the one in the antiperowskites like Ba3SnO. The group‐subgroup relation connecting the two metal rich oxides is presented. The indide anion [In6]16− is similar in shape to tetrafluorethene with a central short In‐In bond (288.4 pm) and four longer In‐In contacts towards the terminal In atoms. The formal electron deficiency and the shape of the anion are discussed on the basis of the calculated electronic structure (using FP‐LAPW bandstructure methods) and compared to the bonding situation in other binary alkaline earth indides and indide nitrides.
Rare‐Earth Nickel Nitridoborates with (BN) Anions: Characterized RENi(BN) and Anticipated REM(BN) Compounds
Authors: Neukirch Michael , Blaschkowski Björn , Häberlen Marco , Meyer H.‐Jürgen 
Published: August 2006

AbstractThe compounds RENi(BN) with RE = Y, La, Ce, Pr, Tm and Yb were synthesized by solid state reactions from metal powders and α‐BN at temperatures between 1000° and 1200 °C. In addition, the mixed phases (Ca,Yb)Ni(BN) and (Ca,Tm)Ni(BN) were synthesized. All products were characterized by powder XRD measurements and indexed isotypic with the structure of CaNi(BN), consistent with the tetragonal space group P4/nmm. The bonding conditions of the (BN) anion are discussed in a perspective view on new nitridoborate compounds REM(BN) containing transition metal atoms (M) other than Ni.
Coordination Chemistry of Acrylamide. 5. Crystal Structures of Complexes of Metal(II) Perchlorates and Tetrafluoroborates with Acrylamide
Authors: Girma Kibatu B. , Lorenz Volker , Blaurock Steffen , Edelmann Frank T. 
Published: August 2006

AbstractAcrylamide complexes of metal perchlorates and tetrafluoroborates, [M(OC(NH2)CH=CH2)6][X]2 (M = Fe, Co, Ni, Zn; X = ClO4, BF4), have been prepared and characterized using single crystal X‐ray diffraction, IR spectroscopy and elemental analyses. The complexes contain metal(II) cations surrounded by an octahedral array of acrylamide ligands accompanied by the anions. The tetrafluoroborate or perchlorate counter anions do not coordinate to the metal atoms or take part in strong secondary interactions such as hydrogen bonds with coordinated ligands. Single crystal X‐ray structures of these complexes prove that the ligands are coordinated exclusively via the carbonyl oxygen atom. Bonding through the nitrogen atom has not been observed in these complexes.
Chiral Cadmium(II), Nickel(II) Complexes of C2‐symmetric (R, R)‐et‐pybox: Syntheses, Crystal Structures and Spectral Properties
Authors: Li Jianping , Zhao Jianshe 
Published: August 2006

AbstractTwo novel chiral complexes Ni((R, R)‐et‐pybox)(H2O)2Cl]Cl (1) and [Cd((R, R)‐et‐pybox)Cl2]·0.5CHCl3 (2) ((R, R)‐et‐pybox is C2‐symmetric 2,6‐bis[4′‐(R)‐ethoxyoxazolin‐2′‐yl]pyridine) have been synthesized and characterized by elemental analysis, IR, UV, TG and single crystal X‐ray diffraction. A feature of interest is noted in the unit cells of the two complexes, there exist two types of molecules per asymmetric unit, which are only slightly differ in the orientation of the coordinated atoms to the central metal atoms. Each Ni atom in 1 has a distorted octahedral and each Cd atom in 2 has a distorted trigonal bipyramidal coordination environment. In complex 1 the two types of molecules interact with each other by O–H···Cl hydrogen bonds, giving rise to one‐dimensional ribbon structure.
Syntheses and Structures of Lithium and Sodium Salt Complexes with Alkylpolyamine Ligands
Authors: Buttery Jarrod H. N. , Plackett Neil C. , Skelton Brian W. , Whitaker Claire R. , White Allan H. 
Published: August 2006

AbstractSyntheses and single crystal X‐ray structural characterizations are recorded for some complexes of lithium and sodium halides, MX, X = Cl, Br, I, with various alkylpolyamine ligands ‘lm(n)’ = [H2N(CH2)lNH(CH2)m(NH(CH2)n)NH2], lm(n) = 22, 222, 343, also 22′2″ = N((CH2)2NH2)3, and ‘apz’ = bis‐1,4‐(2‐aminoethyl)piperazine, obtained by crystallization of the metal salt from solution in the neat base, or with the base in methanol solution. The complex LiCl : 22 (2:2) is a discrete dimer, the four‐coordinate lithium atoms being bridged by the pair of polyamine ligands, with the chlorine atoms terminally bound. The complex LiBr : 22 (2:3) comprises a one‐dimensional cationic polymer, four‐ and five‐coordinate lithium atom types both being coordinated by discrete tridentate bases, and catenated by another, the anions remaining uncoordinated. A hydrolysis product LiBr : 22 : H2O (4:5:1) comprises a cationic web in two dimensions, the counterion remaining uncoordinated. The series of isomorphous complexes NaX : 222 (2:3), X = Br, I, are two‐dimensional polymers, the sodium ions (on crystallographic 3‐axes) being linked into a web normal to those axes by ligands which behave as chelates with pendant groups linking Na(en)3 (en = 1,2‐ethane‐diamine) type arrays, the counterions remaining uncoordinated. The adduct LiCl : apz (2:1), derivative of impurity in the 222 ligand, is also a two‐dimensional web, the four‐coordinate lithium atoms being linked by counterions in one dimension, and chelate‐pendant‐bridging ligands in the other. The complex LiI : 343 (1:1) is a one‐dimensional helical polymeric cation, the four‐coordinate lithium atoms being linked by bis(chelate)‐bridging ligands with unbound counterions. The complexes of 22′2″ take two extreme forms, both manifested in LiCl : 22′2″ (2:2), wherein one set of crystallographically independent lithium atoms, disposed on crystallographic 3‐axes, are linked by extended 22′2″ ligands centred about another set of such axes, (the counterions remaining unbound), into a two‐dimensional web normal to the 3‐axes of the crystal, the other set being bound by the other set of ligands as mononuclear tripod arrays, a motif found in other complexes where the counterion may or may not occupy a fifth coordination site. Here it does not, but in the complex LiBr : 22′2″ (2:2), we find both possibilities: [BrLi(22′2″)][Li(22′2″)]Br, the Li‐Br distance in the neutral aggregate being 2.83(2) Å, while in LiI : 22′2″ (1:1) we have the remarkable prospect of the lithium atoms of a pair of [Li(22′2″)]+ cations confronting each other along a crystallographic 3‐axis (Li…Li 2.82(2) Å), the counterions being disposed on another set of 3‐axes between the cations. The adduct NaI : 22′2″ (1:1) is [INa(22′2″)], Na‐I 3.101(2) Å.
The Structural Characterization of some t‐Butanol Solvates of some Lithium Halides, of LiX : tBuOH(1 : 4,6) Ratio
Authors: Buttery Jarrod H. N. , Plackett Neil C. , Skelton Brian W. , Whitaker Claire R. , White Allan H. 
Published: August 2006

AbstractThe single crystal structural characterization of an array of t‐butanol solvates of the lithium halides LiX, X = Cl, Br, I is recorded. Two series have been identified, of LiX : tBuOH ratio 1:4 and 1:6, represented by the formulations [Li(HOtBu)4]X (X = Cl, I; not isomorphous) and [Li(HOtBu)4]X·2tBuOH (all X = Cl, Br, I, also BH4); isomorphous, triclinic $P{\bar 1}$, a ∼ 10.3, b ∼ 13, c ∼ 14.4Å, α ∼ 73, β ∼ 70, γ ∼ 68°, Z = 2. Li‐O are 1.97Å, in an environment of $quasi-{\rm \bar 4}{\rm 2}m$ symmetry, the pair of O‐Li‐O angles trans to each other which contain the hydroxyl hydrogen atoms being reduced to (range) 92.9(2)‐98.2(3)°. Interactions between these hydroxylic hydrogen atoms with the anions link the cations and anions alternately into chains in the 1:4 adducts; in the 1:6 adducts these chains are extended by interposed solvent molecules by way of hydrogen‐bonding interactions.
Facile Routes to Sodium Tetradecaphosphide Na4P14 and Molecular Structure of Na4(DME)7.5P14 and Na4(en)6P14 (DME = 1,2‐dimethoxyethane; en = ethylenediamine)
Authors: Miluykov Vasili , Kataev Alexander , Sinyashin Oleg , Lönnecke Peter , Hey‐Hawkins Evamarie 
Published: August 2006

AbstractTetrasodium tetradecaphosphide Na4P14 was obtained either from the reaction of PCl3 with sodium in refluxing THF or from the reaction of red phosphorus and sodium in ethylenediamine at room temperature. The solid‐state structures of Na4(DME)7.5P14 (1a) and Na4(en)6P14 (1b) (DME = 1,2‐dimethoxyethane; en = ethylenediamine) are described.
Dimorphic CeZnPO and PrZnPO
Authors: Lincke Hannes , Nilges Tom , Pöttgen Rainer 
Published: August 2006

AbstractWell‐shaped single crystals of the phosphide oxides CeZnPO and PrZnPO were obtained from the rare earth metals, zinc oxide, and red phosphorous in an equimolar NaCl/KCl flux in sealed quartz ampoules. The high‐temperature (β) NdZnPO type modifications were obtained at 1170 K while the low‐temperature (α) ZrCuSiAs type modifications crystallized at 970 K. The four compounds were characterized by X‐ray diffraction on powders and single crystals: P4/nmm, a = 401.08(9), c = 882.0(4) pm, wR2 = 0.1277, 173 F2 values, 9 variables for α–CeZnPO, a = 399.3(2), c = 877.2(7) pm, wR2 = 0.0583, 220 F2 values, 12 variables for α–PrZnPO, and R3m, a = 401.2(4), c = 3121(3) pm, wR2 = 0.0221, 509 F2 values, 14 variables for β–CeZnPO, a = 399.0(2), c = 3108(1) pm, wR2 = 0.0452, 291 F2 values, 14 variables for β–PrZnPO. In both modifications we observe clear separation into rare earth–oxygen and zinc–phosphorous layers without any P–P and Zn–O interactions, leading to electron precise formulations Ce3+Zn2+P3−O2− and Pr3+Zn2+P3−O2− for these transparent compounds. The crystal chemical peculiarities are briefly discussed.
LiBx (0.82 < × ≤ 1.0) – an Incommensurate Composite Structure below 150 K
Authors: Wörle Michael , Nesper Reinhard , Chatterji Tapan K. 
Published: August 2006

AbstractThe lithium boride LiBx (0.82 < × ≤ 1.0) contains linear boron chains isolelectronic to carbyne. The negatively charged boron chains are embedded in and stabilized by a lithium matrix. At room temperature they are disordered with respect to each other and also not commensurate with the Li matrix. Below about 150 K a phase transition takes place, where the boron chains successively order with respect to each other, but remaining still incommensurate with the Li substructure. The crystal structure of LiBx at 2 K was determined from neutron powder diffraction data and refined in the (3+1)‐dimensional superspace group $P{\bar 1}$(αβγ) The unit cell parameters are a = 4.012(1) Å, b = 4.012(1) Å, c = 2.794(1) Å, α = 90°, β = 90°, γ = 120° for the lithium and a = 4.017(1) Å, b = 4.019(1) Å, c = 1.578(1) Å, α=93.35(1), β = 92.83(1)°, γ = 119.71(1)° for the boron substructure, respectively. The q‐vector is (0.1267 0.1482 1.7707). The boron atoms within the linear chains are equidistant, suggesting a cumulated double bond system, similar to a cumulenic chain in the carbon case. Band structure calculations and the electron localization function give more insight into the unusual physical properties of LiBx.
DNA diagnosis of pyruvate dehydrogenase deficiency in female patients with congenital lactic acidaemia
Authors: Matsuda J. , Ito M. , Naito E. , Yokota I. , Kuroda Y. 
Published: August 2006

SummaryThe diagnosis of pyruvate dehydrogenase (PDH) E1α deficiency, which is an X‐linked inborn error of metabolism, is usually established by the measurement of PDH complex activity in cultured cells. However, heterozygous female patients with PDH E1α deficiency may be misdiagnosed when the normal X chromosome is predominantly expressed in the cultured cells. Therefore, in female patients with convincing clinical presentations of PDH E1α deficiency and the normal enzyme activity, the X‐inactivation pattern should be analysed and the PDH E1α gene screened for mutations. For this screening, we applied the method of single‐strand conformational polymorphism (SSCP) and DNA sequencing and examined 11 female patients with congenital lactic acidaemia whose PDH complex activity was normal in cultured cells. In 2 of the 11 female patients, we found distinct pathogenic missense mutations in the PDH E1α gene (G89S and G291R). Both affected patients showed a similar clinical presentation and had been diagnosed as West syndrome. In 3 of the 11 patients, we found a polymorphic base‐pair substitution in exon 9 of the PDH E1α gene which resulted in a changed amino acid residue (M282L). We conclude that PCR‐SSCP analysis of the PDH E1α gene, followed by DNA sequencing, is a useful method to screen for mutations of the PDH E1α gene in female patients with congenital lactic acidaemia who have normal enzyme activities in available samples, normal ratio of lactate to pyruvate, and predominantly raised lactate concentration in cerebrospinal fluid.