(E4,E10)-dodecadienyl acetate: Novel sex pheromone component of tentiform leafminer,Phyllonorycter mespilella (Hübner) (Lepidoptera: Gracillariidae)

(E4,E10)-dodecadienyl acetate (E4,E10-12OAc) is a newly discovered sex pheromone component of the tentiform leafminer,Phyllonorycter mespilella (Hübner). In apple orchards, traps baited with 1g ofE4,E1012OAc attractedP. mespilella in British Columbia andP. blancardella (F.) in Massachusetts and Nova Scotia. The compound was identified inP. mespilella by gas chromatographic-electroantennographic analysis (GC-EAD) of pheromone gland extracts, retention index calculations, EAD profiles toE3 toE10 dodecenyl acetates, and synthesis of candidate pheromone components. Even thoughE4,E10-12OAc was not detected in gland extracts by GC-mass spectroscopy, several factors indicate that it is female-produced. Antennal responses to gland extracts coincided with authenticE4,E10-12OAc on four GC columns with different retention characteristics.E4,E10-12OAc andE10-12OAc, a known female-produced pheromone component, elicited equally strong EAD responses. In field tests,E4,E10-12OAc was two to four times more attractive thanE10-12OAc. There was no additive or synergistic effect between the two components.     

Investigation of sex pheromone components of female asian corn borer,Ostrinia furnacalis (Hübner) (Lepidoptera: Pyralidae) in Taiwan

(E)-12-Tetradecenyl acetate (E12–14OAc), (Z)-12-tetradecenyl acetate (Z12–143nOAc), and tetradecanyl acetate (14OAc) were extracted and identified as major chemical components from female tips of the Asian corn borer,Ostrinia furnacalis (Hübner) (Lepidoptera: Pyralidae) in Taiwan, with a combined wash ratio of 483715 and an individual female ratio of 453916. The average amount ofE12-,Z12–14OAc and 14OAc in each female gland was 6.6±4.6, 5.8±3.5, and 2.4±1.7 ng/female, respectively. The mixture of these three synthetic chemicals not only gave strong activities in male antennae but also could catch significantly more males than virgin females in field-trapping tests. The field test also showed no significant difference in trapping ability among the three-component Taiwan formulations, the two-component Taiwan formulation (Z12–14OAc andZ1214OAc, 5347), and the Japan formulation (Z12–14 OAc andE 12–14OAc, 3:2).     

Response of males to female sex pheromone in the orange wheat blossom midge,Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae)

Males of the orange wheat blossom midge,Sitodiplosis mosellana (Géhin), were attracted by female but not by male extract in a Y-tube bioassay. In laboratory mating experiments, females exhibited typical calling behavior under all conditions tested. At 19C in the dark, males exhibited a high frequency of wing vibration (a courtship behavior) and mating attempts, and 68% of females were mated. However, there was virtually no courtship or mating activity at 17C and 23C (0 and 11% mated, respectively); at 21C, there was an intermediate level (43% mated). Light intensity of 1500 lux (as compared to darkness), or high relative humidity (96%, as compared to 70%) also inhibited mating activity. In trapping experiments in a wheat field, males but not females were caught in significantly greater numbers in traps baited with a solvent extract of virgin females, as compared with unbaited traps, at a trap height of 20 cm. At a trap height of 60 cm above ground, no males were caught. Males did not differentiate between traps baited with two calling females and a solvent extract of two virgin females, and the latter lost little activity over 48 hr under field conditions. There was a daily rhythm of male response to receptive females or female extract each evening between 1700 and 2200 hr CST. The sensitivity of males to environmental conditions and their consequent short daily period of response in the field are thought to be related to their high susceptibility to desiccation and lack of sources of food as adults.     

Crystal structure and luminescence properties of novel Sr10−x(SiO4)3(SO4)3O:xEu2+ phosphor with apatite structure

In this paper, a series of novel luminescent Sr_10−x(SiO₄)₃(SO₄)₃O:xEu²⁺ phosphors with apatite structure were synthesized by a high temperature solid-state reaction. The phase structure, photoluminescence (PL) properties, as well as the PL thermal stability were investigated. Sr_9.92(SiO₄)₃(SO₄)₃O:0.08Eu²⁺ phosphor exhibits better thermal quenching resistance, retaining the luminance of 66.55% at 150 °C compared with that at 25 °C. The quenching concentration of Eu²⁺ in Sr₁₀(SiO₄)₃(SO₄)₃O was about 0.08 (mol) with the dipole–quadrupole interaction. The Sr_10−x(SiO₄)₃(SO₄)₃O:xEu²⁺ phosphors exhibited a broad-band green emission at 538 nm upon excitation at 396 nm. The results indicate that Sr_10−x(SiO₄)₃(SO₄)₃O:xEu²⁺ phosphors have potential applications as near UV-convertible phosphors for white-light UV LEDs.     

A novel 3D coordination polymer [Cd15(μ4-Mtta)12(μ3-Mtta)6(μ3-SO4)4(μ3-OH)4]: Synthesis,structure and solid properties

A 3D coordination polymer, {[Cd₁₅(μ₄-Mtta)₁₂(μ₃-Mtta)₆(μ₃-SO₄)₄(μ₃-OH)₄] · 6H₂O}_n (1) (Mtta = 5-methyl-tetrazolate), which shows the rare multifunction of in situ formed Mtta and bright photo-induced blue emission, was isolated from a hydrothermal reaction of CdSO₄ · 8/3H₂O, NaN₃ in acetonitrile and water.     

A novel 1-D mixed-valence cobalt coordination polymer bridged with (μ-Oalkoxo) and (μ-carboxylate) units: Synthesis,structure and properties

A novel one-dimensional helical mixed-valence cobalt coordination polymer (1) {[Co^IICo^III(HL)₂(OAc)]·CH₃OH·H₂O}_n, (H₃L = 2-ethyl-2-((2-hydroxynaphthalen-1-yl)methyleneamino)propane-1,3-diol) has been synthesized and characterized. Single-crystal X-ray diffraction analyses reveal that complex 1 crystallizes in the tetragonal I4(1)/a space group. It consists of a bimetallic Co^IICo^III(μ₂-O)₂ core, and the adjacent Co^II(2) centers are sequentially bridged by carboxylate groups in the syn–anti fashion, affording to a one-dimensional infinite helical chain along the c-axis. Adjacent chains are stacked via CH···π interactions to form the overall three-dimensional supramolecular networks. Magnetic and in vitro anticancer activities of the complex have been investigated in detail.     

Fatty acid-specific, regiospecific, and stereospecific hydroxylation by cytochrome P450 (CYP152B1) from Sphingomonas paucimobilis: Substrate structure required for α-hydroxylation

Fatty acid α-hydroxylase from Sphingomonas paucimobilis is an unusual cytochrome P450 enzyme that hydroxylates the α-carbon of fatty acids in the presence of H₂O₂. Herein, we describe our investigation concerning the utilization of various substrates and the optical configuration of the α-hydroxyl product using a recombinant form of this enzyme. This enzyme can metabolize saturated fatty acids with carbon chain lengths of more than 10. The K _m value for pentadecanoic acid (C₁₅) was the smallest among the saturated fatty acids tested (C₁₀–C₁₈) and that for myristic acid (C₁₄) showed similar enzyme kinetics to those seen for C₁₅. As shorter or longer carbon chain lengths were used, K _m values increased. The turnover numbers for fatty acids with carbon chain lengths of more than 11 were of the same order of magnitude (10³ min⁻¹), but the turnover number for undecanoic acid (C₁₁) was less. Dicarboxylic fatty acids and methyl myristate were not metabolized, but monomethyl hexadecanedioate and ω-hydroxypalmitic acid were metabolized, though with lower turnover values. Arachidonic acid was a good substrate, comparable to C₁₄ or C₁₅. The metabolite of arachidonic acid was only α-hydroxyarachidonic acid. Alkanes, fatty alcohols, and fatty aldehydes were not utilized as substrates. Analysis of the optical configurations of the α-hydroxylated products demonstrated that the products were S-enantiomers (more than 98% enantiomerically pure). These results suggested that this P450 enzyme is strictly responsible for fatty acids and catalyzes highly stereo- and regioselective hydroxylation, where structure of ω-carbon and carboxyl carbon as well as carbon chain length of fatty acids are important for substrate-enzyme interaction.     

α-Functional glycopolymers: New materials for (poly)peptide conjugation

The synthesis and characterization of a number of N-(hydroxy)succinimidyl ester-terminated glycopolymers obtained via copper(I)-catalysed living radical polymerisation have been described. Monomers employed were based on protected glucose and galactose, glucofuranoside monomer (1) and galactopyranoside monomer (2). The corresponding polymers featured a relatively narrow molecular weight distribution (PDI=1.10-1.31) and M_n between 4.5 and 10.2 kDa. The protecting groups were removed by treatment with formic acid. Analogous fluorescent polymers have been synthesized by copolymerisation of a monomer which fluoresces in the visible, the fluorescent behaviour of these materials has been investigated. Preliminary experiments have also shown that the terminally functional sugar polymers can react with molecules containing primary amino groups and some triblock ABA copolymers have been prepared.     

An unusual intramolecular metallalactone formation from coordinated alkoxide and CO: molecular structure of Au3Ru3{μ3-η1:η1:η1,η2-CCHCPh2OC(O)}(CO)8(PPh3)3

Sequential treatment of Ru₃(μ-H){μ₃-C₂CPh₂(OH)}(CO)₉ with K[BHBu^s₃] and AuCl(PPh₃) afforded Au₃Ru₃{μ₃-η¹:η¹:η¹,η²-CCHCPh₂OC(O)}(CO)₈(PPh₃)₃, formed by intramolecular attack of alkoxide on an adjacent CO ligand, and characterised by a single-crystal X-ray study.     

Bis(cyclopentadienyl) lanthanide benzylthiolate: synthesis,molecular structure and catalytic property for ε-caprolactone –polymerization

Reaction of LnCl₃ first with three equivalent of C₅H₅Na in THF, then with one equivalent of benzyl mercaptan, led to complexes of [(C₅H₅)₂Ln(SCH₂Ph)]₂ (Ln?=?Sm(1), Yb(2)), being characterized by infrared spectra, elemental analyses and X-ray crystallography for 2. Complex 2 is a dimer with two thiolate ligands as bridging groups in eight coordinate. The Yb-S(benzyl) bonds in 2 (2.703(19) and 2.719(2) Å, respectively) were longer than the Yb-S(aryl) bonds (about 2.640 Å) in analogous complexes. The catalytic property for the polymerization of ε-caprolactone by 1 and 2 was studied. Similar experiment was also made with [(C₅H₅)₂Ln(SPh-p-CH₃)(THF)]₂ (Ln?=?Sm(3), Yb(4)) for comparison. It was found that complex 2 showed the activity best, and the activity decreased in the order of 2?>?3?>?1?>?4. When [ε-CL]₀/[Ln] was 500 and the polymerization temperature was 35°C, complex 2 catalyzed the polymerization in living character, which could not be achieved by lanthanide arylthiolates such as 3 and 4.     

Synthesis,structure, and properties of two novel copper(II) complexes, [Cu(phen)(L)2]·6H2O and [Cu(phen)3]·(ClO4)2

Two novel copper(II) complexes, namely [Cu(phen)(L)₂]·6H₂O (1) and [Cu(phen)₃]·(ClO₄)₂ (2) have been synthesized under mild condition (HL = 5-methyl-1H-pyrazole-3-carboxylic acid, phen = 1,10-phenanthroline). We report the structural evidence of discrete water decamer conformation in the solid state. These units are found to act as supramolecular glue in the aggregation of mononuclear copper(II) complex to give a three-dimensional network through hydrogen-bonding. The preliminary investigation on the thermal behavior and the anion exchange property of the complexes are presented.     

A novel π-conjugated polymer : poly(3,4-bis(phenylene)-3-cyclobutene-1,2-dione)

We have investigated a new 1,2-type aromatic dibromide monomer for preparing a modified π -conjugated poly(p-phenylenevinylene). A novel π -conjugated poly(p-phenylenevinylene) was prepared by dehalogenation polycondensation of a dibromoaromatic compound with a squaric unit as a monomer with zerovalent nickel [Ni(0)] complex. The monomer and the polymer were characterized by FT-IR, ¹H-NMR, Elemental Anaylsis, TGA, DSC, GPC and UV-Visible. The resultant polymer had good solubility to polar aprotic, solvents, e.g. DMF, DMAc, DMSO and NMP and solvatochromism in DMAc. Received: 17 July 1998/Revised version: 14 December 1998/Accepted: 15 December 1998     

Synthesis,crystal structure,luminescent property and DFT investigation on a novel metal–organic framework constructed from rigid tetrapodal ligand 1,2,3,4-tetra(4-pyridyl)thiophene

Employing the tetrapodal compound 1,2,3,4-tetra(4-pyridyl)thiophene (TPT) as a bridging ligand, a new metal–organic framework was obtained and characterized by single crystal X-ray diffraction, [Cd(TPT)(N₃)₂·(H₂O)] (1). This polymer exhibits a 2D layer network and an unprecedented 3,4-connected topology, which is constructed from the three-connector TPT and EE azido bridges. It also displays good thermal stability and strong photoluminescence in the blue regionband thus may serve as a candidate of thermally stable blue-light-emitting electroluminescence material. The nature of electronic transitions in the photoluminescent process has also been investigated by means of time-dependent density functional theory (TDDFT) calculations and molecular orbital analyses, which shows that the luminescent property is ligand-based.     

Au anchored to (α-Fe2O3)-MCM-41-HS as a novel magnetic nanocatalyst for water-medium and solvent-free alkyne hydration

A novel catalytic system based on Au nanoparticle functionalized magnetic mesoporous silica was prepared as (α-Fe₂O₃)-MCM-41-HS-Au. This material was obtained through the reaction of ordered mesoporous silica-coated magnetic nanoparticles (α-Fe₂O₃)-MCM-41, (3-mercaptopropyl) trimethoxysilane (MPTMS) and HAuCl₄. This catalyst was extensively characterized by various techniques such as SEM, TEM, XRD, EDX, IR and N₂-sorption isotherm. Very uniform dispersion and ordered mesopores of (α-Fe₂O₃)-MCM-41-SH (about 2–3 nm) causes Au nanoparticles to be distributed very finely on the pore surfaces, resulting in a very useful and robust magnetically recyclable catalyst for water-medium and solvent-free alkyne hydration.     

A novel constant interfacial area cell for determining the extraction kinetics of Er(Ⅲ) from chloride medium

A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.     

A novel three-dimensional 3d–4f heterometallic coordination polymer with unique (3,4)-connected topology and helical units: Synthesis,crystal structure and photoluminescence property

One new three-dimensional 3d–4f heterometallic coordination polymer, namely, {[EuZn₂(imdc)₂(C₂O₄)_0.5(H₂O)₄]·2H₂O}_n (1) (H₃imdc = imidazole-4,5-dicarboxylic acid), has been successfully synthesized by the hydrothermal reactions of Eu₂O₃, Zn(NO₃)₂·6H₂O, H₃imdc, H₂C₂O₄·2H₂O and H₂O. Single-crystal X-ray diffraction analysis reveals that complex 1 possesses 3D heterometallic framework containing 2D layer based on L–Zn2–L (L = imdc) helical chains and L–EuZn1–L chains. Complex 1 exhibits unprecedented (3,4)-connected four-nodal topology with Schläfli symbol (6·7·8) (6·7·9) (6·7²·8²·10) (7·8²). Moreover, the photoluminescence property of 1 was investigated in the solid-state at room temperature.     

α-Dioxygenases (α-DOXs): Promising Biocatalysts for the Environmentally Friendly Production of Aroma Compounds

Fatty aldehydes (FALs) can be derived from fatty acids (FAs) and related compounds and are frequently used as flavors and fragrances. Although chemical methods have been conventionally used, their selective biotechnological production aiming at more efficient and eco-friendly synthetic routes is in demand. α-Dioxygenases (α-DOXs) are heme-dependent oxidative enzymes biologically involved in the initial step of plant FA α-oxidation during which molecular oxygen is incorporated into the C_α-position of a FA (C_n) to generate the intermediate FA hydroperoxide, which is subsequently converted into the shortened corresponding FAL (C_n-1). α-DOXs are promising biocatalysts for the flavor and fragrance industries, they do not require NAD(P)H as cofactors or redox partner proteins, and they have a broad substrate scope. Here, we highlight recent advances in the biocatalytic utilization of α-DOXs with emphasis on newly discovered cyanobacterial α-DOXs as well as analytical methods to measure α-DOX activity in vitro and in vivo.     

Synthesis of a novel tetranuclear Cu(II) complex with the dinucleating ligand α,α′-bis(N-1,4,7-triazacyclononane)-m-xylene (XYL-tacn): first crystal structure of [(CuCl)4(XYL-tacn)2(μ-Cl)2][PF6]2

Reaction of the ligand α,α^′-bis(N-1,4,7-triazacyclononane)-m-xylene (XYL-tacn) with copper(II) chloride and sodium hexafluorophosphate in acetonitrile/methanol leads to the assembly of a remarkable tetranuclear copper(II) complex. The crystal structure and magnetic properties of the novel tetranuclear Cu(II) complex are reported. The complex exhibits an unusual [(CuCl)₄(μ-Cl)₂] binding mode with a Cu··· Cu distance of 6.856(3) Å.