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Lignans are a large class of secondary metabolites in plants, with numerous biological effects in mammals, including antitumor and antioxidant activities. Sesamin, the most abundant furofuran-class lignan in sesame seeds (Sesamum plants), is produced by the cytochrome P450 enzyme CYP81Q1 from the precursor lignan, pinoresinol. In contrast, Forsythia plants produce dibenzylbutyrolactone-class lignans, such as matairesinol, from pinoresinol via the catalysis of pinoresinol/lariciresinol reductase (PLR) and secoisolariciresinol dehydrogenase. Here we present the engineering of lignan biosynthesis in Forsythia cell suspension cultures for the development of an efficient production method of beneficial lignans. A suspension cell culture prepared from leaves of Forsythia koreana produced lignans, mainly pinoresinol and matairesinol glucosides, at levels comparable with that obtained from the leaves. In an attempt to increase the pinoresinol content in Forsythia, we generated a transgenic cell line overexpressing an RNA interference (RNAi) construct of PLR (PLR-RNAi). Down-regulation of PLR expression led to a complete loss of matairesinol and an accumulation of approximately 20-fold pinoresinol in its glucoside form in comparison with the non-transformant. Moreover, the Forsythia transgenic cells co-expressing CYP81Q1 and PLR-RNAi exhibited production of sesamin as well as accumulation of pinoresinol glucoside. These data suggest Forsythia cell suspension to be a promising tool for the engineering of lignan production. To the best of our knowledge, this is the first report on transgenic production of an exogenous lignan in a plant species.

Crystal structure analysis of the title compound revealed the presence of a hydrogen bond in an intermolecular LH⋯L contact with the O⋯O distance of 2.4252(16) A to form a one-dimensional polymeric structure. Magnetic study clarified that a relatively large exchange coupling was determined as 2J/kB = −33.2(2) K from the Bonner–Fisher analysis and ascribable to the super–superexchange coupling along the Cu–O–H⋯O–Cu path.

In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N=3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R(2) values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs

The phytochrome photoreceptors regulate plant growth and development throughout their life cycle. Rice (Oryza sativa) possesses three phytochromes, phyA, phyB, and phyC. Physiological, genetic, and biochemical analyses of null mutants of each phytochrome have revealed the function of each in rice. However, few studies have investigated the relationship between phytochrome signaling and metabolism. In the present study, non-targeted metabolite analysis by gas chromatography time-of-flight mass spectrometry (GC/TOF-MS) and targeted metabolite analysis by capillary electrophoresis electrospray ionization mass spectrometry (CE/ESI-MS) were employed to investigate metabolic changes in rice phyA phyB phyC triple mutants. Distinct metabolic profiles between phyA phyB phyC triple mutants and the wild type (WT), as well as those between young and mature leaf blades, could be clearly observed by principal component analysis (PCA). The metabolite profiles indicated high accumulation of amino acids, organic acids, sugars, sugar phosphates, and nucleotides in the leaf blades of phyA phyB phyC triple mutants, especially in the young leaves, compared with those in the WT. Remarkable overaccumulation of monosaccharide, such as glucose (53.4-fold), fructose (42.5-fold), and galactose (24.5-fold), was observed in young leaves of phyA phyB phyC triple mutants. These metabolic phenotypes suggest that sugar metabolism, carbon partitioning, sugar transport, or some combination of these is impaired in the phyA phyB phyC triple mutants, and conversely, that phytochromes have crucial roles in sugar metabolism.

We successfully isolated a new paramagnetic bidentate ligand tert-butyl 5-methoxy-2-pyridyl nitroxide (meopyNO). Complexation of nickel(II) and copper(II) perchlorates with meopyNO gave the corresponding ML2-type bis-chelated compounds. The magnetic studies showed that they were ground high-spin molecules with 2J/kB = +288(5) and +178(3) K for [M(meopyNO)2(H2O)2] · (ClO4)2 (M = Ni and Cu, respectively), where the spin Hamiltonian is defined as H = −2J(S1 · S2 + S2 · S3). From the crystallographic analysis, the torsion angles (ϕ) around M–O–N–C2py were 4.2(3)° and 6.87(19)°, respectively, being so small that the orthogonality between the magnetic radical π∗ and the metal dσ orbitals would be guaranteed.

Heterometallic polymeric coordination compounds [{Ln(hfac)2(CH3OH)}2{Cu(dmg)(Hdmg)}2]n ([Ln2Cu2]n; Ln = Tb, Ho, and Er; H2dmg = dimethylglyoxime; Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) were synthesized, and the X-ray crystallographic analysis shows that their structures are isomorphous to those of the known ferrimagnetic [Gd2Cu2]n and [Dy2Cu2]n analogs. The exchange couplings in [Tb2Cu2]n, [Ho2Cu2]n, and [Er2Cu2]n were precisely evaluated by high-frequency EPR and pulsed-field magnetization studies, giving JTb−Cu/kB = −0.77(2) K, JHo−Cu/kB = −0.250(12) K and JEr−Cu/kB = −0.149(15) K. They were comparable to those of the Gd and Dy analogs. The absolute value of the exchange coupling parameter monotonically decreases in the order of Gd, Tb, Dy, Ho, and Er.

The production of oat (Avena sativa L.) phytoalexins, avenanthramides, occurs in response to elicitor treatment with oligo-N-acetylchitooligosaccharides. In this study, avenanthramides production was investigated by techniques that provide high spatial and temporal resolution in order to clarify the process of phytoalexin production at the cellular level. The amount of avenanthramides accumulation in a single mesophyll cell was quantified by a combination of laser micro-sampling and low-diffuse nanoflow liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) techniques. Avenanthramides, NAD(P)H and chlorophyll were also visualized in elicitor-treated mesophyll cells using line-scanning fluorescence microscopy. We found that elicitor-treated mesophyll cells could be categorized into three characteristic cell phases, which occurred serially over time. Phase 0 indicated the normal cell state before metabolic or morphological change in response to elicitor, in which the cells contained abundant NAD(P)H. In phase 1, rapid NAD(P)H oxidation and marked movement of chloroplasts occurred, and this phase was the early stage of avenanthramides biosynthesis. In phase 2, avenanthramides accumulation was maximized, and chloroplasts were degraded. Avenanthramides appear to be synthesized in the chloroplast, because a fluorescence signal originating from avenanthramides was localized to the chloroplasts. Moreover, our results indicated that avenanthramides biosynthesis and the hypersensitive response (HR) occurred in identical cells. Thus, the avenanthramides production may be one of sequential events programmed in HR leading to cell death. Furthermore, the phase of the defense response was different among mesophyll cells simultaneously treated with elicitor. These results suggest that individual cells may have different susceptibility to the elicitor.

A 4f−3d heterometallic polymeric coordination compound [{Dy(hfac)2(CH3OH)}2{Cu(dmg)(Hdmg)}2]n ([Dy2Cu2]n; H2dmg = dimethylglyoxime; Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) was synthesized, and the X-ray crystallographic analysis shows that the structure is isomorphous to the known ferrimagnetic [Gd2Cu2]n polymer. A centrosymmetric diamond-arrayed ferrimagnetic unit involving the oximate bridge, Dy−O−N−Cu, is repeated to form a discrete chain. An onset of the frequency dependence was found in the ac magnetic susceptibility measurements down to 1.8 K. Low-temperature magnetization measurements on [Dy2Cu2]n exhibited magnetic hysteresis with magnetization steps. To examine the energy level structure and the exchange coupling between the Dy and Cu ions, high-frequency EPR (HF-EPR) spectra of a polycrystalline sample of [Dy2Cu2]n were recorded at various frequencies (34.7−525.4 GHz) and temperatures. We analyzed the spectra by treating the Dy moments as Ising spins and built an exchange-coupling model...

Commercial development of trans-1,4-polyisoprene from Eucommia ulmoides Oliver (EU-rubber) requires specific knowledge on selection of high-rubber-content lines and establishment of agronomic cultivation methods for achieving maximum EU-rubber yield. The development can be facilitated by high-throughput and highly sensitive analytical techniques for EU-rubber extraction and quantification. In this paper, we described an efficient EU-rubber extraction method, and validated that the accuracy was equivalent to that of the conventional Soxhlet extraction method. We also described a highly sensitive quantification method for EU-rubber by Fourier transform infrared spectroscopy (FT-IR) and pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). We successfully applied the extraction/quantification method for study of seasonal changes in EU-rubber content and molecular weight distribution.

In this study, metabolite profiling was demonstrated as a useful tool to plot a specific metabolic pathway, which is regulated by phytochrome A (phyA). Etiolated Arabidopsis wild-type (WT) and phyA mutant seedlings were irradiated with either far-red light (FR) or white light (W). Primary metabolites of the irradiated seedlings were profiled by gas chromatography time-of-flight mass spectrometry (GC/TOF-MS) to obtain new insights on phyA-regulated metabolic pathways. Comparison of metabolite profiles in phyA and WT seedlings grown under FR revealed a number of metabolites that contribute to the differences between phyA and the WT. Several metabolites, including some amino acids, organic acids, and major sugars, as well as putrescine, were found in smaller amounts in WT compared with the content in phyA seedlings grown under FR. There were also significant differences between metabolite profiles of WT and phyA seedlings during de-etiolation under W. The polyamine biosynthetic pathway was investigated further, because putrescine, one of the polyamines existing in a wide variety of living organisms, was found to be present in lower amounts in WT than in phyA under both light conditions. The expression levels of polyamine biosynthesis-related genes were investigated by quantitative real-time RT-PCR. The gene expression profiles revealed that the arginine decarboxylase 2 (ADC2) gene was transcribed less in the WT than in phyA seedlings under both light conditions. This finding suggests that ADC2 is negatively regulated by phyA during photomorphogenesis. In addition, S-adenosylmethionine decarboxylase 2 and 4 (SAMDC2 and SAMDC4) were found to be regulated by phyA but in a different manner from the regulation of ADC2.

We prepared tetranuclear complexes [{Cu(emg)(Hemg)(ROH)}2{Dy(hfac)2(ROH)}2] (abbreviated as [Dy2Cu2]-R; R = Me, Et; H2emg = ethylmethylglyoxime) and the corresponding polymer [{Cu(dmg)(Hdmg)}2{Dy(hfac)2(CH3OH)}2]n · 2(MeOH) ([Dy2Cu2]n; H2dmg = dimethylglyoxime), which were characterized as analogs of the known [Gd2Cu2] monomer and polymer, respectively, by means of X-ray crystallographic analysis. The M–H curves clarified antiferromagnetic coupling between Dy and Cu in the [Dy2Cu2] motif, leading to the Dy magnetic moments aligned parallel ([Cu(↓)Dy(↑)Cu(↓)Dy(↑)]). Ac magnetic susceptibility measurements of [Dy2Cu2]-Me and [Dy2Cu2]n exhibited a χ ac ′ (in-phase) decrease and a concomitant χ ac ″ (out-of-phase) increase with an increase of frequency. Low-temperature magnetization measurements on [Dy2Cu2]n exhibited magnetic hysteresis, which is characteristic of single-chain magnets.

We successfully synthesized and characterized two precursors for paramagnetic chelating ligands, N-p-anisyl-N-2-pyridylhydroxylamine and 2,6-bis(N-t-butylhydroxylamino)pyridine. The former can be regarded as a rare case since N,N-diarylhydroxylamines cannot be isolated in general because of facile autoxidation. The oxidation with silver(I) oxide gave radicals showing typical nitroxide ESR signals, but the resultant radicals were unstable under ambient conditions. Theoretical DFT calculation indicated that the bisnitroxide radical, pyridine-2,6-diyl bis(t-butyl nitroxide), had a triplet ground state.

Ferromagnetic exchange coupling was operative between nickel(II) spins in a dinuclear nickel(II) complex [{Ni(hfac)2}2(py4C)] with J/kB = +0.57(2) K (H = −2JS1 · S2), where hfac and py4C stand for 1,1,1,5,5,5-hexafluoropentane-2,4-dionate and tetrakis(2-pyridyl)methane, respectively. X-ray crystal structure analysis revealed an approximate D2d symmetry of the [Ni(py4C)Ni] core and accordingly the orthogonal arrangement between the two coordination basal planes. Mechanism of the ferromagnetic coupling was proposed on the basis of the orthogonal dσ-type magnetic orbitals, which was supported by DFT calculation.

Chlorophyllase (Chlase) catalyzes the initial step of chlorophyll (Chl)-degradation, but the physiological significance of this reaction is still ambiguous. Common understanding of its role is that Chlase is involved in de-greening processes such as fruit ripening, leaf senescence, and flowering. But there is a possibility that Chlase is also involved in turnover and homeostasis of Chls. Among the de-greening processes, autumnal coloration is one of the most striking natural phenomena, but the involvement of Chlase during autumnal coloration is not clear. Previously, it was shown that Chlase activity and expression level of the Chlase gene were not increased during autumnal coloration in Ginkgo biloba, indicating that Chlase does not work specially in the de-greening processes in G. biloba. In this study, we characterized the recombinant Chlase and analyzed its subcellular localization to understand the role of the cloned Chlase of G. biloba (GbCLH). GbCLH exhibited its highest activity at pH 7.5, 40 °C. Kinetic analysis revealed that GbCLH hydrolyzes pheophytin (Pheo) a and Chl a more rapidly than Pheo b and Chl b. Transient expression analysis of 40 N-terminus amino acids of GbCLH fused with GFP (green fluorescent protein) and subcellular fractionation showed that GbCLH localizes within chloroplasts. Together with our previous results, property of GbCLH and its location within the chloroplasts suggest that GbCLH plays a role in the turnover and homeostasis of Chls in green leaves of G. biloba

We designed spiro-fused dinculear complexes using tetrakis(2-pyridyl)methane (py4C) for the development of ground high-spin molecules. We attempted to prepare a dinuclear copper(II) complex [{Cu(hfac)2}2(py4C)], where hfac stands for 1,1,1,5,5,5-hexafluoropentane-2,4-dionate, but we obtained [Cu(hfac)2(py4C)] and [Cu(hfac)(py4C) · Cu(hfac)3]. These molecular structures were determined by the X-ray crystal structure analysis.

Orobanche minor is a non-photosynthetic root holoparasitic plant. Although it is known that photosynthesis-related genes are inactivated or have been eliminated from the plastid genomes of holoparasites, little is known about the alterations in their genes involved in the signaling networks by which light regulates photosynthesis. Cryptochromes (crys), which are blue-light receptors, appear to control both photosynthesis-related and non-photosynthetic responses to light in higher plants. Because we are interested in to what extent a cry-mediated light signaling network remains in the holoparasites, we cloned CRY homologous cDNA from O. minor (OmCRY1) and used real-time RT-PCR to compare its expression under natural daylight and darkness. We found that the OmCRY1 has a high degree of homology with CRY1 s from photosynthetic plants. Expression of the OmCRY1 gene was higher in plants grown in the dark than that in the plants grown under natural daylight. This is the first report of the gene expression of a blue-light receptor in non-photosynthetic plants.

Screening of a phage display random 9-mer peptide library, in which cysteine residues were at the both terminals of the 7-mer random region, was performed to obtain an oligopeptide that recognizes a chitin-oligomer. Affinity of the obtained peptide (Cys-Ser-Arg-Thr-Thr-Arg-Thr-Arg-Cys) to chitotriose was modulated by its oxidation–reduction state. Only the oxidized form exhibited specific binding to the target molecule, chitotriose. This is the first report of reversible affinity modulation of a synthetic oligopeptide which can recognize a neutral saccharide.

A new small-pore compound K(4)Fe(4)P(5)O(20) was obtained by conventional solid-state reaction in a closed crucible. The crystal structure is constructed by Fe(4)P(5)O(20) units forming chains along the c axis and elliptical eight-ring channels on the a-b plane in which K cations locate inside. Such structural characteristics seem to be quite similar to those seen in the natrolite family. However, Fe ions in K(4)Fe(4)P(5)O(20) have trigonal-bipyramidal instead of common tetrahedral coordination. Furthermore, our experimental results combined from magnetic susceptibility and (57)Fe Mössbauer spectrum measurements show mixed valence Fe(3+)/Fe(2+) in the titled material. To the best of our knowledge, this is the first example that contains mixed valence iron ions in a so-called natrolite framework.

Manganese (Mn)-doped black iron oxide (Fe3O4) magnetic fluids in the system of MnxFe[Formula: see text]O4 were successfully synthesized from natural magnetite (iron sand) by using co-precipitation method at room temperature. The analyses of the small angle neutron scattering (SANS) data by applying a log-normal sphere with a mass fractal models for [Formula: see text] and [Formula: see text] and two log-normal spheres with a single mass fractal models for [Formula: see text], 0.75 and 1 revealed that the primary particles of the MnxFe[Formula: see text]O4 fluids tended to decrease from 3.8[Formula: see text]nm to 1.5[Formula: see text]nm along with the increasing fraction of Mn contents. The fractal dimension ([Formula: see text]) increased from about 1.2 to 2.7 as the Mn contents were increasing; which physically represents an aggregation of the MnxFe[Formula: see text]O4 particles in the fluids growing up from 1 to 3 dimensions to consolidate a more compact structure. The magnetization curves of the fluids exhibited an increasing saturation magnetization from [Formula: see text] to [Formula: see text], and a decreasing on [Formula: see text] and 0.75, with the maximum achievement of [Formula: see text]. These phenomena may probably be due to the combined effects, arising from cationic and dopant distributions, aggregation and its size, and also fractal dimension. Furthermore, the decrease of blocking temperature of the MnxFe[Formula: see text]O4 magnetic fluids could be associated with the reduced particle sizes, while the freezing temperature had its highest peak intensity when it collectively occurred with the blocking temperature at a similar point of about 270[Formula: see text]K.

The spin-crossover (SCO) phenomenon between a high-spin and a low-spin state has attracted much attention in the field of materials science. Among the various kinds of SCO complexes, the triazole-bridged iron(II) polymeric chain system, [Fe(II)(R-trz)3]X2·xH2O (where trz is triazole and X is the anion), exhibiting the SCO phenomenon with thermal hysteresis around room temperature, has been extensively studied from the viewpoint of molecular memory and molecular devices. In connection with this system, we have controlled the SCO phenomenon according to the characteristic properties of counter ions. In the case of X being CnH2n+1SO3−, the spin transition temperature (T1/2) increases with increasing the length (n) of the alkyl chain of the counter ion and saturates above n = 5, which is attributed to the increase in the intermolecular interaction of the alkyl chains of CnH2n+1SO3−, called the fastener effect. The hysteresis width of T1/2 decreases with increasing n, showing the even-odd, also known as parity, effect. In the cases where X is toluenesulfonate (tos: CH3C6H4SO3−) and aminobenzenesulfonate (abs: NH2C6H4SO3−), T1/2 and its hysteresis width vary drastically with the structural isomerism (ortho-, metha-, and para-substitution) of counter ions, which implies the possibility of photoinduced spin transition by means of the photoisomerization of counter ions. From this strategy, we have synthesized [Fe(II)(NH2-trz)3](SP150)2·2H2O (SP150 = N-alkylsulfonated spiropyran) and investigated the SCO phenomenon. Moreover, we have developed [Fe(II)(R-trz)3]@Nafion films exhibiting spin transition around room temperature, where the Nafion membrane behaves as a counter anion as well as a transparent substrate, and investigated the photogenerated high-spin state below 35 K. The lifetime of the photogenerated high-spin state strongly depends on the intensity of irradiated light.

To develop room-temperature molecule-based magnets, metal–radical approach is one of the most promising strategies. Strong magnetic interactions beyond a thermal energy of room temperature are essential for achieving such coveted materials. We have developed 2-pyridyl tert-butyl nitroxide (2pyNO) derivatives as a chelating radical ligand with a copper(II) or nickel(II) ion. The torsion angle () around M−O−N−C2py is a useful metric in describing correlation between the structure and metal–radical exchange coupling 2J (defined as H = −2JΣSi Si +1). Although we previously reported such a magneto-structural correlation, in this paper we updated the plot of 2J versus by dividing into two categories: the hexacoordinatenickel(II) and copper(II) complexes. An empirical linear correlation was formulated for both Cu and Ni categories, as 2J/k B = a + b|| with a = 503(112) K and b = –36(3) K deg–1 and with a = 449(46) K and b = –21.0(17) K deg–1, respectively. In the latter plot we confirm that the relationship can be generalized for the oxoverdazyl and dithiadiazolyl systems as well as the 2pyNO systems. The results are supported by the calculations based on the density functional theory.

The 4f-3d exchange couplings were definitively and precisely determined in the dinuclear complexes (Ln-M) involving double μ-oxo-bridges, by means of combined high-frequency electron paramagnetic resonance and pulsed-field magnetization techniques, revealing a monotonic decrease of ferromagnetic J(Ln-Cu) in the order of the atomic number, (64)Gd to (68)Er.

The solvent-free spin crossover iron(III) complex [Fe(III)(Him)2(hapen)]AsF6 (Him = imidazole, H2hapen = N,N'-bis(2-hydroxyacetophenylidene)ethylenediamine), exhibiting thermal hysteresis, was synthesized and characterized. The Fe(III) ion has an octahedral coordination geometry, with N2O2 donor atoms of the planar tetradentate ligand (hapen) and two nitrogen atoms of two imidazoles at the axial positions. One of two imidazoles is hydrogen-bonded to the phenoxo oxygen atom of hapen of the adjacent unit to give a hydrogen-bonded one-dimensional chain, while the other imidazole group is free from hydrogen bonding. The temperature dependencies of the magnetic susceptibilities and Mossbauer spectra revealed an abrupt spin transition between the high-spin (S = 5/2) and low-spin (S = 1/2) states, with thermal hysteresis.

We succeeded in acquiring two DNA aptamers that selectively recognize tubulin by the SELEX method. A pool of single-stranded oligo-DNAs including a random region of 59 nucleotides was screened by SELEX for tubulin purified from calf-brain as a target. After 20 repetitions of selection round, the library converged on specific T-rich sequences. The binding activity of T-rich clones was analyzed by the SPR sensor to determine their dissociation constants to be in the order of 10 μM. ©2000 Elsevier Science Ltd. All rights reserved.

DNA aptamers that bind to hematoporphyrin IX (HPIX) were isolated using an in vitro selection technique. Most aptamers obtained after the 7th and 10th rounds contained guanine-rich sequences. Binding assay using fluorescence polarization technique and structural analysis by CD spectra revealed that the parallel guanine-quartet structure of the aptamer participates in the recognition of HPIX.

イミダクロプリド, アセタミプリド, ニテンピラムおよびそれらの類縁化合物のラットとイエバエのニコチン性アセチルコリン受容体に対する結合活性を, [125I] α-bungarotoxin を用いて測定した. 用いた濃度において, すべての化合物がイエバエの受容体に対する結合活性を有したが, ラットの受容体に対しては21化合物しか活性を示さなかった. また, ラットの受容体に対する活性値はイエバエの受容体に対する活性値の1/10～1/10,000であった. なお, これらの殺虫剤のラットに対する毒性の強さは, ラットの受容体に対する結合活性値の高さに対応していた. 本実験の結果より, クロロニコチニル殺虫剤の選択性は, その受容体への結合活性の差によって説明できることが示された.

Variously substituted benzyl derivatives of chloronicotinyl insecticides were synthesized with a wide range of substituents including halogens, NO2, CN, CF3 and small alkyl and alkoxy groups at the ortho, meta and para positions, as well as multiple-substituted benzyl analogues. Their binding activity to the α-bungarotoxin binding site in housefly (Musca domestica) head membrane preparations was measured. Among the compounds tested, the activity of the meta-CN derivative was the highest, being 20–100 times higher than those of imidacloprid, acetamiprid and nitenpyram. The synergized insecticidal activity against houseflies was also measured for selected compounds with the metabolic inhibitor, NIA16388 (propargyl propyl phenylphosphonate). For the nitromethylene analogues, including both benzyl and pyridylmethyl analogues, higher binding activity usually resulted in higher insecticidal activity. © 2000 Society of Chemical Industry

An unstable organic free radical 2pyNO (tert-butyl 2-pyridyl nitroxide) was trapped with transition-metal ions, giving stable metal−radical compounds. Complex [NiII(2pyNO)2(H2O)2]·(ClO4)2 showed intramolecular strong ferromagnetic coupling (J/kB = +126(3) K), while [CuII(2pyNO)2(ClO4)2] showed antiferromagnetic coupling (J/kB = −137(1) K; the spin-Hamiltonian is defined as H = −2JSA·SB).

The binding activity of imidacloprid and related compounds to nico- tinic acetylcholine receptors (nAChR) of house Nies was measured by use of radioactive a-bungarotoxin as a ligand. Variations in the activity were examined three-dimensionally using comparative molecular -eld analysis (CoMFA). The CoMFA results suggest that one conformer among the four stable ones is active and provide support for one of the proposed binding models for this class of compound, in which the nitrogen atom of the pyridine ring and the nitrogen atom at the 1-position of the imidazolidine ring interact with the hydrogen- donating and electron-rich sites of nAChR, respectively. The CoMFA -eld map showed that the nitroimino moiety and a portion of the imidazolidine ring were mainly surrounded by a sterically and electrostatically sensitive region of nAChR. 1998 Society of Chemical Industry ( Pestic. Sci., 54, 134E144 (1998)

We applied high-frequency electron paramagnetic resonance to trinuclear 4f-3d heterometallic complexes, [{Ln(hfac)3}2{Ni(dpk)2(py)2}] (Ln = Y, Gd, Tb, and Ho; hfac = hexafluoroacetylacetonate, dpk = di-2-pyridyl ketoximate, and py = pyridine), and determined the exchange parameter J(Ln-Ni) as well as nickel(II) zero-field splitting parameters. In contrast to the antiferromagnetic Dy analogue, ferromagnetic couplings were precisely characterized as J(Gd-Ni)/kB = +0.301(4) K, J(Tb-Ni)/kB = +0.216(12) K, and J(Ho-Ni)/kB = +0.110(3) K (defined as -J(Ln-Ni)∑J(Ln)(z)S(Ni)).

A synchrotron small-angle X-ray scattering (SAXS) study on PVA/Fe3O4 magnetic hydrogels has been performed to investigate the effect of clustering on their magnetic properties. The hydrogels were prepared through freezing–thawing (F–T) processes. The structure, morphology and magnetic properties of magnetite (Fe3O4) nanoparticles (NPs) were investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM) and a superconducting quantum interference device (SQUID) magnetometer, respectively. In this study, SAXS data were used to reveal the structural dimensions of the magnetite and its distribution in the polymer-rich PVA and magnetic hydrogels. As calculated using the Beaucage and Teubner–Strey models, the average of the structural dimensions of the PVA hydrogels was 3.9[Formula: see text]nm (crystallites), while the average distance between crystallites was approximately 18[Formula: see text]nm. Further analysis by applying a two-lognormal distribution showed that the magnetite NPs comprised secondary particles with a diameter of 9.6[Formula: see text]nm that were structured by primary particles ([Formula: see text][Formula: see text]3.2[Formula: see text]nm). A two-lognormal distribution function has also been used in describing the size distributions of magnetite NPs in magnetic hydrogels. The clusters of magnetite NPs in the magnetic hydrogels are significantly reduced from 30.4[Formula: see text]nm to 12.8[Formula: see text]nm with decreasing concentration of the NPs magnetite from 15[Formula: see text]wt.% to 1[Formula: see text]wt.%. The saturation magnetization values of the magnetite NPs, the 15% and 1% magnetic hydrogels were 34.67[Formula: see text]emu/g, 6.52[Formula: see text]emu/g and 0.37[Formula: see text]emu/g, respectively.

The aim of this study is to investigate the effects of an artificially controlled environment, particularly elevated total pressure, on net photosynthesis and respiration during plant growth. Pressure directly affects not only cells and organelles in leaves but also the diffusion coefficients and degrees of solubility of CO2 and O2. In this study, the effects of elevated total pressure on the rates of net photosynthesis and respiration of a model plant, Arabidopsis thaliana, were investigated in a chamber that newly developed in this study to control the total pressure. The results clearly showed that the rate of respiration decreased linearly with increasing total pressure at a high humidity. The rate of respiration decreased linearly with increasing total pressure up to 0.2 MPa, and increased with increasing total pressure from 0.3 to 0.5 MPa at a low humidity. The rate of net photosynthesis decreased linearly with increasing total pressure under a constant partial pressure of CO2 at 40 Pa. On the other hand, the rate of net photosynthesis was clearly increased by up to 1.6-fold with increasing total pressure and partial pressure of CO2.

Magnetic coordination polymers can exhibit controllable magnetism by introducing responsiveness to external stimuli. This report describes the precise control of magnetism of a cyanide-bridged bimetallic coordination polymer (Prussian blue analogue: PBA) through use of an electrochemical quantitative Li ion titration technique, i.e., the galvanostatic intermittent titration technique (GITT). K(0.2)Ni[Fe(CN)(6)](0.7)·4.7H(2)O (NiFe-PBA) shows Li ion insertion/extraction reversibly accompanied with reversible Fe(3+)/Fe(2+) reduction/oxidation. When Li ion is inserted quantitatively into NiFe-PBA, the ferromagnetic transition temperature T(C) gradually decreases due to reduction of paramagnetic Fe(3+) to diamagnetic Fe(2+), and the ferromagnetic transition is completely suppressed for Li(0.6)(NiFe-PBA). On the other hand, T(C) increases continuously as Li ion is extracted due to oxidation of diamagnetic Fe(2+) to paramagnetic Fe(3+), and the ferromagnetic transition is nearly recovered for Li(0)(NiFe-PBA). Furthermore, the plots of T(C) as a function of the amount of inserted/extracted Li ion x are well consistent with the theoretical values calculated by the molecular-field approximation.

Single crystals of the title compound are synthesized by solid state reaction of K2CO3, Fe2O3, NH4H2PO4, and KF (alumina crucible, 1050 °C, 10 h).

Plants emit green leaf volatiles (GLVs) in response to insect or pathogen damage. GLVs consist of C6 and C9 aldehydes, alcohols, and their acetate esters, and play important roles in the plant defense response. One of the functions of GLVs in the defense response is priming. Plants pretreated by GLVs can induce a defense response more rapidly and effectively than unpretreated plants when they are damaged by pathogens or insects. In this study, we focused on the priming effects of GLVs on jasmonic acid response involved in the defense response. When Arabidopsis was pretreated with aldehyde GLVs, especially with (E)-2-hexenal, the anthocyanin content was significantly increased by a subsequent methyl jasmonate (MeJA) treatment. On the other hand, no effect of anthocyanin accumulation was observed for plants pretreated with alcohol GLVs. These results suggest that aldehyde GLVs, especially (E)-2-hexenal, could enhance sensitivity to MeJA in Arabidopsis.

The insecticidal activity of imidacloprid and related compounds against American cockroaches was measured by injection with and without metabolic inhibitors. Metabolic inhibitors increased the activity more than 10-fold. Neurophysiological effects of the compounds on excised cockroach nerve preparations were measured in terms of the frequency of spontaneous discharges and were biphasic with time. Activity derived from the concentration required to increase the maximum frequency to a certain level was evaluated for each compound. When the factor of transport within the insect body was separated using the hydrophobicity parameter, variations in the insecticidal activity were linearly related to the nerve activity, with higher nerve activity corresponding to higher insecticidal activity.

Exchange couplings in isomorphous [LnCu(2)] were evaluated by high-frequency electron paramagnetic resonance and magnetization studies. The exchange parameter J(Ln-Cu) was decreased with an increase in the atomic number; J(Ln-Cu)/k(B) = 4.45(11), 2.27(6), 0.902(10), 0.334(3), and 0.136(8) K for Ln = Gd, Tb, Dy, Ho, and Er, respectively.

Magnetic measurements on single crystals of the title compound show that it exhibits an unexpected large magnetic anisotropy energy of up to 107 erg/cm3 at 5 K.

The ground spin-state of [Cu(phpyNO)(2)(H(2)O)(2)](BF(4))(2) was switched between S(total) = 1/2 and 3/2 across 175 K. On warming, the space group was changed from P2(1)2(1)2(1) to C222(1) in a single-crystal-to-single-crystal manner, and the transient structure could be monitored by means of the crystallographic analysis. The copper-radical exchange coupling changed from 2J/k(B) = -463(3) to +312(6) K with rather small Cu-O-N-C(2py) twisting deformation on one side, while practically no distortion occurred on the other.

Two novel copper(II) complexes with tert-butyl 2-pyridyl nitroxide (2pyNO(*)), [Cu(2+)(2pyNO(-))(2pyNO(*))](2)(BF(4)(-))(2) (1 x BF(4)) and [Cu(2+)(2pyNO(-))(2pyNO(*))](2)(ClO(4)(-))(2) (1 x ClO(4)), were prepared and structurally characterized. They contained mixed-valent ligands from 2pyNO, whose oxygen atoms were located at equatorial positions of the copper ion. The [Cu(2+)(2pyNO(-))(2pyNO(*))] unit was dimerized by mu-oxo bridges of the anion ligand, giving a zigzag linear spin system involving four paramagnetic S = 1/2 centers. The two compounds are isomorphous in an orthorhombic Pbca space group. Magnetic study revealed that 1 x ClO(4) showed ferromagnetic copper-radical coupling in all temperature ranges investigated here. On the other hand, 1 x BF(4) exhibited a structural phase transition at 64 K, where the magnetic susceptibility was drastically dropped on cooling. The copper-radical magnetic couplings were characterized as ferro- and antiferromagnetic for the high- and low-temperature phases, respectively. The crystallographic analysis clarified that the nitroxide oxygen atom remained at the equatorial position throughout the single-crystal-to-single-crystal phase transition, while the previously known spin-transition-like copper-radical compounds showed conversion of the roles of equatorial and axial positions. The orthogonal arrangement between the copper d sigma and nitroxide pi* orbitals is essential for the ferromagnetic coupling, and a slight dislocation of the radical oxygen atom from the chelate plane leads to violation of the orthogonal orbital arrangement, giving a practically diamagnetic low-temperature phase.

N-Glycosylation is an important post-translational modification that occurs in many secreted and membrane proteins in eukaryotic cells. Golgi alpha-mannosidase I hydrolases (MANI) are key enzymes that play a role in the early N-glycan modification pathway in the Golgi apparatus. In Arabidopsis thaliana, two putative MANI genes, AtMANIa (At3g21160) and AtMANIb (At1g51590), were identified. Biochemical analysis using bacterially produced recombinant AtMANI isoforms revealed that both AtMANI isoforms encode 1-deoxymannojirimycin-sensitive alpha-mannosidase I and act on Man(8)GlcNAc(2) and Man(9)GlcNAc(2) structures to yield Man(5)GlcNAc(2). Structures of hydrolytic intermediates accumulated in the AtMANI reactions indicate that AtMANIs employ hydrolytic pathways distinct from those of mammalian MANIs. In planta, AtMANI-GFP/DsRed fusion proteins were detected in the Golgi stacks. Arabidopsis mutant lines manIa-1, manIa-2, manIb-1, and manIb-2 showed N-glycan profiles similar to that of wild type. On the other hand, the manIa manIb double mutant lines produced Man(8)GlcNAc(2) as the predominant N-glycan and lacked plant-specific complex and hybrid N-glycans. These data indicate that either AtMANIa or AtMANIb can function as the Golgi alpha-mannosidase I that produces the Man(5)GlcNAc(2) N-glycan structure necessary for complex N-glycan synthesis.

Summary • Holoparasitic plants such as Orobanche spp. have lost their photosynthetic ability, so photoresponses to optimize photosynthesis are not necessary in these plants. Photoresponses are also involved in the regulation of plant development but the photoresponses of holoparasites have not been characterized in detail. In this study, the phytochrome (phy)-related photoresponse of Orobanche minor was investigated. Its photoreceptor, phytochrome A (OmphyA), was also characterized. • Light effects on germination, shoot elongation, anthocyanin biosynthesis, and OmphyA expression and subcellular localization were analyzed. • Red light (R):far-red light (FR) reversible inhibition of O. minor seed germination demonstrated that phy-mediated responses are retained in this holoparasite. Shoot elongation was inhibited by FR but not by R. This pattern is unique among known patterns of plant photoresponses. Additionally, molecular analysis showed that OmphyA is able to respond to the light signals. • Interestingly, the unique pattern of photoresponses in O. minor seems to have been modified for adaptation to its parasitic life cycle. We hypothesize that this alteration has resulted from the loss or alteration of some phy-signaling components. Elucidation of altered components in phy signaling in this parasite will provide useful information not only about its physiological characteristics but also about general plant photoreception systems.

The exchange couplings in [{Dy(hfac)3}2Cu(dpk)2] and [{Dy(hfac)3}2Ni(dpk)2(py)2] (Hdpk = di-2-pyridyl ketoxime) were precisely evaluated by high-frequency electron paramagnetic resonance and pulsed-field magnetization studies, giving J(Dy-Cu)/kB = -0.126 K and J(Dy-Ni)/kB = +0.031 K.

We have isolated and characterized a new paramagnetic bidentate ligand, tert-butyl 5-phenyl-2-pyridyl nitroxide (phpyNO). The spin distribution onto the pyridine ring was clarified from the Electron Spin Resonance spectrum. Complexation of phpyNO with nickel(II) and copper(II) ions gave ML 2-type chelated compounds. The magnetic measurements of [Ni(phpyNO) 2(H 2O) 2].(ClO 4) 2 and [Cu(phpyNO) 2(H 2O)].(ClO 4) 2.C 6H 4Cl 2 revealed that the metal-radical exchange couplings were ferromagnetic with 2 J/ k B = +409(10) and +434(12) K, respectively. The torsion angle (varphi) around M-O-N-C 2py can be regarded as a reliable indicator for the plane geometry of chelates; namely, highly planar chelates defined by small varphi exhibit ferromagnetic coupling. An approximate linear relation was found in the J versus varphi plot using the data of the present complexes and related known compounds. The critical angle of varphi, at which the sign of the metal-radical exchange changes from positive to negative, was 12.6(9) degrees . This finding could be almost reproduced by density-functional theory calculation on a model copper(II)-nitroxide dyad. The exchange couplings in equatorially coordinated copper(II)- and nickel(II)-nitroxide complexes are very strongly ferromagnetic by nature.

Commercial development of natural polyisoprene from polyisoprene-producing plants requires detailed knowledge on how to select high-polyisoprene-content lines and establish agronomic cultivation methods for achieving maximum polyisoprene yield. This development can be facilitated by a high-throughput quantification method for natural polyisoprene. In this paper, we describe the Fourier transform near infrared spectroscopy (FT-NIR) technique coupled with a partial least squares (PLS) regression model to quantify natural polyisoprene in Eucommia ulmoides leaves. PLS regression models are discussed with respect to linearity, root-mean-square error of estimation (RMSEE), and root-mean-square error of prediction (RMSEP). The best PLS regression model was obtained with second derivative NIR spectra in the region between 4000-6000 cm(-1) (R2Y, 0.95; RMSEE, 0.25; RMSEP, 0.37). This is the first report to employ FT-NIR analysis for high throughput and solvent-free quantification of natural polyisoprene in leaves.

A paramagnetic ligand 6bpyNO (2,2‘-bipyridin-6-yl tert-butyl nitroxide) is a newcomer in the field of metal-radical hybrid magnetic materials. Complexes [CuII(6bpyNO)Cl2] and [NiII(6bpyNO)2](PF6)2 having highly planar chelate rings showed considerably strong ferromagnetic exchange couplings J/kB = 202 and 192 K, respectively, across the direct radical oxygen coordination bonds (the spin Hamiltonian is defined as −2JSi·Sj).