Efficient Synthesis of a Water-Soluble Glucoamide Inhibitor Against Human Aldose Reductase by Click Chemistry

While D-glucose is the natural substrate of aldose reductase (AR) in the polyol pathway, the K _m value of D-glucose against AR is large. A glucoamide 1 was designed as a tool to investigate whether AR has a strong affinity for the open form of D-glucose. Glucoamide 1 was synthesized in high yield by modification of the reaction condition for click chemistry. It was found that our modified condition was applicable for highly polar alkynes and gave coupling products in excellent yield (90% to 100%). Although weak inhibitory activity against AR was observed, kinetic studies showed that AR does not accept glucoamide 1 in its active site.     

A new trans-dioxorhenium(V) complex with 4-aminopyridine: synthesis,structure, electrochemical aspects,DFT, and TD-DFT calculations

The reaction of 1?:?4.4?M proportion of cis-[ReO₂I(PPh₃)₂] and 4-aminopyridine (ampy) in acetone–water gives trans-[ReO₂(ampy)₄]I·2H₂O (1a) in 85% yield. 1a has been characterized by C, H, and N microanalyses, FT-IR, UV–vis, ¹H NMR spectroscopy, and molar conductivity. The X-ray crystal structure of 1a reveals an octahedral trans dioxorhenium(V) complex with a “N₄O₂” coordination for rhenium. 1a has an orthorhombic space group C2221 with a?=?17.576(4), b?=?19.370(4), c?=?15.730(4) Å, V?=?5355(2) ų, and Z?=?8. Geometry optimization of the trans-O,O complex, 1a and its cis-O,O analog, 1b performed at the level of density functional theory reveal that 1a is more stable than 1b by 25?kcal M^–1 in the gas phase. The electronic spectrum of 1a was also analyzed at the level of time-dependent density functional theory. Excitation of 1a in methanol at 450?nm leads to a fluorescent emission at 505?nm with a quantum yield (Ф) of 0.04. Electrochemical studies of 1a in acetonitrile show a quasi-reversible Re(V) to Re(VI) oxidation at 0.618?V versus Ag/AgCl. This redox potential matches with the calculated redox potential of 0.621?V versus Ag/AgCl.     

Syntheses,characterization, and X-ray crystal structures of two cis-dioxovanadium(V) complexes of pyrazole-derived,Schiff-base ligands

Two mononuclear cis-dioxovanadium(V) complexes of pyrazole-derived, Schiff-base ligands have been synthesized and characterized. Single crystal X-ray analyses were performed with N ′-[(3-methyl-1H-pyrazole-5-yl)carbonyl]pyridine-2-carbohadrazonamido cis-dioxovanadium(V), {[VO₂(PzOAP)] · H₂O} (1), and 5-methyl-N-[(1E)-1-(pyridin-2-yl)ethylidene]-1H-pyrazole-3-carbohydrazonate cis-dioxovanadium(V), {[VO₂(PzCAP)]} (2). Both complexes crystallize in monoclinic crystal systems with different space groups. Complex 1 crystallizes in the space group P21/c, 2 in space group C2/C. In each complex, the vanadium sits within a distorted square pyramidal geometry with an N₂O₃ chromophore. The τ parameters of the complexes (0.33 for 1, 0.22 for 2) support their square pyramidal geometry. The interesting finding in the work is that the alkoxide oxygen, imino nitrogen, and pyridine nitrogen take part in the coordination process leaving the pyrazole rings inactive in coordination.     

Photo-Induced Switchable Binding Behavior of Bridged Bis(β-cyclodextrin) with an Azobenzene Dicarboxylate Linker

A bridged bis(β-cyclodextrin) (1) with an azobenzene dicarboxylate linker was synthesized, and its binding behavior with a fluorescent dye, acridine red (AR), was investigated by means of fluorescence spectroscopy. Due to the photo-induced conversion of the azobenzene dicarboxylate linker from the trans-conformer to the cis-conformer, 1 exhibits a different binding behavior before and after UV light irradiation, giving a stronger binding ability towards AR in the cis form. This switchable binding behavior of 1 may open a new channel to the design of azobenzene-linked dimeric receptors as photo-induced molecular devices.     

Electrochemical transformations of antimony(V) complexes containing tridentate O,N,O-donor ligands

Electrochemical transformations of antimony(V) complexes containing a tridentate redoxactive ligand, N,N-bis-(2-hydroxy-di-3,5-tert-butylphenyl)amine: R ₃Sb(Cat-NH-Cat) (R = (1) Ph; (2) Et), (3) Et₂Sb(Cat-N-Cat)) are studied. Electrochemical oxidation of complexes 1, 2 occurs irreversibly leading to formation of unstable radical cations. The next stage is the chemical process resulting in formation of neutral paramagnetic compounds. The Et₂Sb(V)(Cat-N-Cat) complex is characterized by two reversible anodic redox processes corresponding to a change of in the ligand redox level. Stable paramagnetic derivatives are formed as a result of electrochemical oxidation of compounds 1, 3; this allows considering these compounds as potential radical scavengers. Interaction of complex 1 with electrogenerated superoxide radical anion led to formation of paramagnetic reaction products.     

The Use of Electrospray Mass Spectrometry (ES/MS) for the Differential Detection of Some Steroids as Calix-[n]-arene Sulphonate Complexes

Non-covalent inclusion complexes formed between three p-sulphonato-calix-[n]-arenes (1 n = 4, 2 n = 6 and 3 n = 8) and three steroids (progesterone, testosterone and oestradiol) have been studied by electrospray mass spectrometry (ES/MS). Mass spectrometric titration experiments have demonstrated differences with regard to selectivity of each p-sulphonato-calix-[n]-arene against the steroids. p-sulphonato-calix-[8]-arene interacts more strongly with oestradiol and p-sulphonato-calix-[6]-arene with progesterone. Studies in which different orifice voltages were applied show that all oestradiol complexes are reduced in signal intensity at 50 V as compared to 20 V, whereas the intensities observed for the testosterone and progesterone complexes do not vary with voltage. Competition experiments confirm the selectivity of the complexation.     

Synthesis, crystal structure, and spectra of 9(E)-phenanthrene-9,10-dione[(1Z)-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]hydrazone and its cation-anion complex with copper(I) bromide

The reaction of 1-hydrazino-3,3-dimethyl-3,4-dihydroisoquinoline with 9,10-phenanthrenequinone gave (9E)-phenanthrene-9,10-dione[(1Z)-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]hydrazone (L). The reaction of L with copper(II) bromide gave the complex (LH)[CuBr₂]. The crystal structures of the monohydrate L · H₂O (I) and the isolated complex (LH)[CuBr₂] (II) were determined by X-ray diffraction. The structural units of I are pseudo-centrosymmetric dimers in which the L and water molecules are combined by strong hydrogen bonds. The active H atom is located at the N(1) atom of the isoquinoline fragment of the L molecule. The L molecule occurs in the crystal as the cis, trans isomer with respect to exocyclic C=N bonds at the isoquinoline and phenanthrenequinone fragments, respectively. Complex II has a cation-anion structure. The LH⁺ cation as the cis, cis isomer is protonated at N(2) and stabilized by two intramolecular hydrogen bonds. In the CuBr₂⁻ anion, the copper atom in the oxidation state +1 has a linear coordination, the C-Br bond length is 2.185(4) ± 0.005 ?, and the BrCuBr angle is 179.8(4)°. The main ion-ion interactions in structure II are shortened contacts involving bromine atoms, which combine cations and anions into a three-dimensional framework. Original Russian Text ? V.V. Davydov, V.I. Sokol, N.V. Rychagina, R.V. Linko, M.A. Ryabov, Yu.V. Shklyaev, V.S. Sergienko, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 6, pp. 958–970.     

Synthesis, structures, and electrophysical properties of single crystals of solid solutions CdGeAs2:Mn(x) and Cd0.964Zn0.036GeAs2:Mn(x)

Single crystals of the solid solutions CdGeAs₂:Mn(x) and Cd_0.964Zn_0.036GeAs₂:Mn(x) have been grown by the vertical Bridgman method. An X-ray diffraction study has demonstrated that Cd_0.964Zn_0.036GeAs₂ (I), Cd_0.964Zn_0.036GeAs₂:Mn (1.5 wt%) (II), and Cd_0.964Zn_0.036GeAs₂:Mn (2.18 wt %) (III) retain the CdGeAs₂ structure (tetragonal system, space group I 2d). The unit cell parameters of the solid solutions are as follows: a = b = 5.934(1) ?, c = 11.219(2) ? for I; a = b = 5.919(1) ?, c = 11.204(2) ? for II; and a = b = 5.918(1) ?, c = 11.208(2) ? for III. Many of Mn atoms in II and III occupy interstitial sites in the crystal lattice. Selected electrical and magnetic properties of single crystals of CdGeAs₂:Mn(x) are discussed. Original Russian Text ? S.G. Mikhailov, K.K. Palkina, A.V. Molchanov, S.F. Marenkin, T.V. Filippova, L.I. Ochertyanova, I.S. Zakharov, A.V. Kochura, R. Laiho, E. Lahderanta, A. Lashkul, M.A. Shakhov, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 11, pp. 1879–1885.     

Synthesis,characterization and crystal structures of oxidovanadium(V) hydrazone complexes with antibacterial activity

Abstract

Reaction of VO(acac)₂ with the hydrazone ligands N’-(2-hydroxybenzylidene)-3methylbenzohydrazide (H₂L¹) and N’-(2-hydroxybenzylidene)-3-methyl-4-nitrobenzohydrazide (H₂L²) afforded two oxidovanadium(V) complexes, [VOL¹(OMe)(MeOH)] (1) and [VOL²(OEt)(EtOH)] (2), respectively. The complexes have been characterized by elemental analyses, IR, UV-Vis, molar conductivity and X-ray single crystal diffraction techniques. The hydrazone ligands coordinate to the V ions through the phenolate oxygen, imino nitrogen and enolate oxygen atoms. The V ions in both complexes are in octahedral coordination, with the three donor atoms of the hydrazone ligands, and with the other three sites furnished by one methanol or ethanol oxygen atom, one deprotonated methanol or ethanol oxygen atom, and one oxo oxygen. The complexes were assayed for their antibacterial activity on the bacteria B. subtilis, E. coli, P. putida and S. aureus.     

双(取代水杨醛)缩卡巴肼及其苄基锡配合物的合成、表征、荧光性质和除草活性

用5-甲基水杨醛、4-二乙氨基水杨醛分别与卡巴肼或硫代卡巴肼缩合,制得1,5-二取代卡巴肼或硫代卡巴肼配体。在微波甲醇溶剂热条件下,二苄基二氯化锡前体与配体反应,合成了双(取代水杨醛)缩(硫代)卡巴肼苄基锡配合物T1～T4,但T4的结构与T1～T3不同,T4由N,N′-双(4-二乙氨基水杨醛)缩连氮及甲氧基桥联锡组成的苄基锡配合物,T4还可由卡巴肼、4-二乙氨基水杨醛和二苄基二氯化锡"一锅法"合成。T1～T4的结构经元素分析、IR、1H/13C NMR表征,并用X射线衍射法确证配合物T4的晶体分子结构。T4属单斜晶系,P21/c空间群,中心锡原子与氮、氧、苄基碳和氯原子组成六配位变形八面体构型。T4在DMF-H2O溶液中具有良好的荧光性质,当含水量0～30%(V/V)时具有聚集荧光增强效应,含水量大于30%时,随含水体积分数增加荧光强度减弱,以至最后淬灭。配合物对马齿苋具有良好的生长抑制作用,T1和T3对决明子、T2对苋菜和T4对四九菜心具有选择性生长抑制作用,可作为除草剂的候选化合物进一步研究。     

Vanadium(V) Complexes of O,N,O-Donor Tridentate Ligands Containing the {VVO(OMe)}2+ Unit: Syntheses,Structures and Properties

Abstract

Syntheses, characterisation and properties of two complexes containing the oxovanadium(V) methoxide unit have been described. Deprotonated benzoylhydrazones of 2–hydroxy–5–methoxy‐benzaldehyde (H₂bhsOMe) and 2–hydroxy–5–chlorobenzaldehyde (H₂bhsCl) were used as coligands. Crystal structures of both the complexes were determined. In solid state one of them is a dinuclear species [VO(bhsOMe)(OMe)]₂ (1) whereas the other one is a mononuclear complex [VO(bhsCl)(OMe)(HOMe)](2). The dinegative ligands coordinate the metal ions via phenolate–O, imine–N and deprotonated amide–O atoms. In 1, the metal ions of two square pyramidal VO(bhsOMe)(OMe) units share the methoxide groups to form a dinuclear species. The oxygen of a methanol molecule completes the hexacoordination of the metal centre in 2. In each of the two distorted octahedral VO₅N moieties of 1 the bridging methoxide oxygen and in that of 2 the methanol oxygen is trans to the corresponding oxo group. Both the complexes are redox active. The VO³⁺ to VO²⁺ reduction potentials (vs Ag/AgCl) of 1 and 2 are observed at ?0.25 and ?0.04 V, respectively. The band positions in the electronic spectra and the redox potentials reflect the influence of the substituents present on the ligands.     

Synthesis and DFT calculations of oxido and phenylimido-rhenium(V) complexes incorporating the N,O donor ligand 2-[(2-hydroxyethylimino)methyl]phenol

The reactions of equimolar amounts of trans-[ReOC1₃(PPh₃)₂] or trans-[Re(NPh)(PPh₃)₂Cl₃] with a Schiff base formed by condensation of 2-hydroxy-4-methoxybenzaldehyde and ethanolamine (H₂L) result in the formation of cis-[ReO(HL)PPh₃Cl₂] (1a) and trans-[Re(NPh)(HL)(PPh₃)Cl₂] (2b), respectively, in good yields. 1a and 2b have been characterized by a range of spectroscopic and analytical techniques. The X-ray crystal structures of 1a and 2b reveal that 1a is an octahedral cis-Cl,Cl oxorhenium(V) complex, while 2b is a trans-Cl,Cl phenylimidorhenium(V) complex. The complexes are weakly emissive at room temperature with quantum yields of 10^?4. Density functional theory calculations of the electronic properties of the complexes were performed and are in agreement with the experimental results. The complexes display quasi-reversible Re(V)/Re(VI) redox couples in acetonitrile. There is reasonable agreement between the experimental and calculated redox potentials of 1a and 2b.     

A Simultaneous,Laser-Excited Fluorescence,Photoacoustic, and Two-Photon Photoionization Detector for Liquid Chromatography

Abstract

A laser-excited windowless flow cell has been developed for simultaneous fluorescence, photoacoustic, and two-photon photoionization detection of aromatic compounds in HPLC eluents. Sensitive three-mode detection of acridine, naphthalene, 7,8-benzoflavone, N-ethylcarbazole, and anthracene in 70/30 V/V acetonitrile/water is demonstrated with conservative detection limits in the nanogram range and below.     

Polarographie in 1,2-Propandiolcarbonat, 3. Mitt.: Verbindungen von Titan,Vanadin und Chrom

Zusammenfassung Titan(III)chlorid, Titan (IV)oxyperchlorat, Vanadin(III)chlorid, Vanadin(IV)oxyperchlorat, Chrom(III)chlorid und Chrom(III)perchlorat wurden in 1,2-Propandiolcarbonat polarographisch untersucht; die Art der Grenzströme, die Diffusionsstromkonstanten, die Diffusionskoeffizienten, die Art der Abscheidungsvorgänge und die Lage der Halbwellenpotentiale, bez. auf die gesätt. wäßr. Kalomelelektrode, wurden bei 25° in 0,1M-Lösungen von Tetraäthylammoniumperchlorat bestimmt. Es wurden die Reduktionsvorgänge Ti(IV)–Ti(III), V(III)–V(II), V(IV)–V(II), Cr(III)–Cr(II) und Cr(II)–Cr(0) aufgefunden, wobei nur V(III)–V(II) reversibel verläuft.

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Polarographic investigation have been carried out on titanium(III)chloride, titanium(IV)oxoperchlorate, vanadium(III)chloride, vanadium(IV)oxoperchlorate, chromium(III)chloride and chromium(III)perchlorate in 1,2-propanediol-carbonate; the nature of the limiting currents, the diffusion current constants, the diffusion coefficients, the reversibility or irreversibility of the electrode process and the half-wave potentials vs. aqueous saturated calomel electrode have been determined in 0,1M solutions of tetraethylammonium perchlorate at 25°. Reduction waves were found corresponding to Ti(IV)–Ti(III), V(III)–V(II), V(IV)–V(II), Cr(III)–Cr(II) and Cr(II)–Cr(0)

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Mit 2 Abbildungen

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1. Mitt.:V. Gutmann, M. Kogelnig undM. Michlmayr, Mh. Chem.99, 693 (1968).

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2. Mitt.:V. Gutmann, M. Kogelnig undM. Michlmayr, Mh. Chem.99, 699 (1968).     

Synthesis,crystal structures,and biological activity of oxovanadium(V) complexes with similar tridentate hydrazone ligands

Two new oxovanadium(V) complexes, [VOL¹(OEt)(EtOH)] (1) and [VOL²(OMe)(MeOH)] (2), were prepared by reaction of [VO(acac)₂] (where acac?=?acetylacetonate) with N′-(3-bromo-2-hydroxybenzylidene)-4-methylbenzohydrazide (H₂L¹) in ethanol and N′-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide (H₂L²) in methanol, respectively. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. The V ions have octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied.     

Pentakis(carbamide)dioxoneptunium(V) Nitrate [NpO2{OC(NH2)2}5](NO3): Synthesis,Crystal Structure,and Some Properties

X-ray diffraction and spectroscopic data for a new Np(V) compound, namely, [NpO₂{OC(NH₂)₂}₅](NO₃) (I) are presented. Crystals are monoclinic, space group P2₁, a = 11.142(2) Å, b = 7.6379(9) Å, c = 11.143(2) Å, = 108.9(1)°, Z = 2, V = 897.1(2) ų. The neptunium atom has a typical pentagonal-bipyramidal environment with five oxygen atoms of the carbamide molecules in the equatorial plane. The nitrate ion is in the outer sphere. Carbamide is a strong molecular ligand with respect to Np(V) and hence, cation–cation bonds of the NpO₂ ⁺ ions are not realized in structure I. The wave length of the f–f transition in the electronic absorption spectra of crystalline complex I and Np(V) in a saturated carbamide solution is virtually the same and is equal to 991 nm.     

Elektrochemische Untersuchungen in Phenylphosphoroxychlorid, 5. Mitt.: Eine Verbesserung der Methode zur Bestimmung von Spuren Wasser und von organischen Stoffen mit aktivem Wasserstoff

Zusammenfassung Es wird eine Zelle beschrieben, welche die Serienbestimmung von Wasser sowie von organischen Verbindungen mit aktivem Wasserstoff an der Quecksilbertropfelektrode gestattet.Mit 1 Abbildung4. Mitt.:H. Dehn, V. Gutmann undG. Schöber, Mh. Chem.94, 312 (1963). H. Dehn, V. Gutmann undG. Schöber, Mh. Chem.93, 1357 (1962).     

Synthesis and photovoltaic properties of polymeric metal complexes containing 8-hydroxyquinoline as dye sensitizers for dye-sensitized solar cells

Four new donor–acceptor type polymeric metal complexes (P1, P2, P3, and P4) with the same Cd(II) complex in side chain and different conjugated backbone structures were synthesized by Yamamoto coupling and applied in dye-sensitized solar cells (DSSCs) as photosensitizers. The photophysical, electrochemical, and thermal properties were investigated in detail, showing that conjugated backbone containing fluorene improved intramolecular charge transfer and increased generation of photocurrent. The highest power conversion efficiency of 0.56% (J _sc?=?1.63?mA?cm^?2, V _oc?=?0.69?V, FF?=?0.50) was obtained with a DSSC based on P3 under simulated air mass 1.5 G solar irradiation, which shows a new strategy to design photosensitizers for DSSCs.     

Novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties: Design,synthesis, and insecticidal activity

Abstract

A series of novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties were designed, synthesized, and evaluated for their insecticidal activity. Bioassays indicated that some of the target compounds exhibited good insecticidal activities against Plutella xylostella (P. xylostella), Vegetable aphids (V. aphids), and Empoasca vitis (E. vitis). In particular, compound (E)-2-((5-(2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropyl)-1,3,4-oxadiazol-2-yl)thio)-N'-(4-(trifluoromethyl)benzylidene)acetohydrazide (6s) revealed excellent insecticidal activities against P. xylostella, V. aphids, and E. vitis with the 50% lethal concentration (LC₅₀) values of 5.23, 7.07, and 1.61?mg/L, respectively, which were similar to or even better than those of chlorpyrifos, beta cypermethrin, spinosad, and azadirachtin. These results indicated that novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties could be developed as novel and promising insecticides.     

α- or β-Substituted functional phthalocyanines bearing thiophen-3-ylmethanol substituents: synthesis,characterization, aggregation behavior and antioxidant activity

The tetra α- or β-thiophene substituted metal and metal-free phthalocyanines (Pcs) M[Pc(α-OCH₂Thiopen)₄] and M[Pc(β-OCH₂Thiopen)₄] {(α-ThMet-MPc), (β-ThMet-MPc) [ThMet: Thiophene methoxy], M = Zn(II), Co(II) and, 2H} were synthesized from the corresponding 3’-(thiophen-3-ylmethoxy)phthalonitrile or 4’-(thiophen-3-ylmethoxy)phthalonitrile (ThMePN). The structural characterization, spectral, and antioxidant properties of a series of new Pcs were also presented. Both α- and β-substituted Pc complexes increased solubility in polar solvents, such as THF, DMF, and DMSO. FT-IR, ¹H-NMR, ¹³C-NMR, UV–vis, MALDI-TOF/MS spectral, and elemental analysis data were used to characterize the compounds. The aggregation behaviors of 3–8 were also investigated at different concentrations in THF. Antioxidant test methods, α,α-diphenyl-β-picrylhydrazyl radical scavenging activity, metal chelating activity, and reducing power, were used to determine the antioxidant activities. 6 showed very good ferrous ion chelating activity of 81 ± 1%. 6, 5, 4, and 3 showed better reducing power than trolox, ascorbic, acid and butylated hydroxytoluene, commercially used antioxidants.