Complete Chloroplast Genome Sequences of Important Oilseed Crop Sesamum indicum L

Sesamum indicum is an important crop plant species for yielding oil. The complete chloroplast (cp) genome of S. indicum (GenBank acc no. JN637766) is 153,324 bp in length, and has a pair of inverted repeat (IR) regions consisting of 25,141 bp each. The lengths of the large single copy (LSC) and the small single copy (SSC) regions are 85,170 bp and 17,872 bp, respectively. Comparative cp DNA sequence analyses of S. indicum with other cp genomes reveal that the genome structure, gene order, gene and intron contents, AT contents, codon usage, and transcription units are similar to the typical angiosperm cp genomes. Nucleotide diversity of the IR region between Sesamum and three other cp genomes is much lower than that of the LSC and SSC regions in both the coding region and noncoding region. As a summary, the regional constraints strongly affect the sequence evolution of the cp genomes, while the functional constraints weakly affect the sequence evolution of cp genomes. Five short inversions associated with short palindromic sequences that form step-loop structures were observed in the chloroplast genome of S. indicum. Twenty-eight different simple sequence repeat loci have been detected in the chloroplast genome of S. indicum. Almost all of the SSR loci were composed of A or T, so this may also contribute to the A-T richness of the cp genome of S. indicum. Seven large repeated loci in the chloroplast genome of S. indicum were also identified and these loci are useful to developing S. indicum-specific cp genome vectors. The complete cp DNA sequences of S. indicum reported in this paper are prerequisite to modifying this important oilseed crop by cp genetic engineering techniques

Development of decision support systems to promote the use of microbial biocontrol of plant diseases

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1,4-Bis(arylthio)but-2-enes as Assembling Ligands for (Cu2X2)n (X= I, Br ; n = 1, 2) Coordination Polymers : Aryl Substitution, Olefin Configuration, and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties

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Stoichiometry-controlled cycloaddition of nitrilimines with unsymmetrical exocyclic dienones: Microwave-assisted synthesis of novel mono- and dispiropyrazoline derivatives

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1,4-Bis(arylthio)but-2-enes as Assembling Ligands for (Cu2X2)n (X= I, Br ; n = 1, 2) Coordination Polymers : Aryl Substitution, Olefin Configuration, and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties

International audienceCuI reacts with E-PhS(CH2CH═CHCH2)SPh, L1, to afford the coordination polymer (CP) [Cu2I2{μ-E-PhS(CH2CH═CHCH2)SPh}2]n (1a). The unprecedented square-grid network of 1 is built upon alternating two-dimensional (2D) layers with an ABAB sequence and contains rhomboid Cu2(μ2-I)2 clusters as secondary building units (SBUs). Notably, layer A, interconnected by bridging L1 ligands, contains exclusively dinuclear units with short Cu···Cu separations [2.6485(7) Å; 115 K]. In contrast, layer B exhibits Cu···Cu distances of 2.8133(8) Å. The same network is observed when CuBr reacts with L1. In the 2D network of [Cu2Br2{μ-E-PhS(CH2CH═CHCH2)SPh}2]n (1b), isotype to 1a, one square-grid-type layer contains Cu2(μ2-Br)2 SBUs with short Cu···Cu contacts [2.7422(6) Å at 115K], whereas the next layer incorporates exclusively Cu2(μ2-Br)2 SBUs with a significantly longer Cu···Cu separation [2.9008(10) Å]. The evolution of the crystallographic parameters of 1a and 1b was monitored between 115 and 275 K. Conversely, the isomeric Z-PhS(CH2CH═CHCH2)SPh ligand L2 reacts with CuI to form the 2D CP [Cu4(μ3-I)4(μ-Z-PhS(CH2CH═CHCH2)SPh}2]n (2a) with closed-cubane SBUs. A dinuclear zero-dimensional complex [Cu2Br2{μ-Z-PhS(CH2CH═CHCH2)SPh}2] (2b) is formed when CuBr is reacted with L2. Upon reaction of E-TolS(CH2CH═CHCH2)STol, L3, with CuI, the 2D CP [{Cu(μ3-I)}2(μ-L3)]n containing parallel-arranged infinite inorganic staircase ribbons, is generated. When CuX reacts with Z-TolS(CH2CH═CHCH2)STol, L4, the isostructural 2D CPs [Cu2X2{μ-Z-TolS(CH2CH═CHCH2)STol}2] (4a X = I; 4b X = Br) are formed. In contrast to the CPs 1a,b, the layers based on rhombic grids of 4a,b incorporate Cu2(μ2-X)2 SBUs featuring uniformly identical Cu···Cu distances within each layer. The TGA traces showed that all these materials are stable up to ∼200 °C. Moreover, the photophysical properties have been studied, including absorption, emission, excitation spectra, and emission lifetimes at 298 and 77 K. The spectra were interpreted using density functional theory (DFT) and time-dependent DFT calculations

Conformational and structural studies of <i>N</i>-methylacetohydroxamic acid and of its mono- and bis-chelated uranium(VI) complexes

The thermodynamics and kinetics of the cis/trans isomerism of N-methylacetohydroxamic acid (NMAH) and its conjugated base (NMA−) have been reinvestigated in aqueous media by 1H NMR spectroscopy. Hindered rotation around the central C–N bond due to electronic delocalization becomes slow enough on the NMR time scale to observe both rotamers in equilibrium in D2O at room temperature. By properly assigning the methyl group resonances, evidence for the prevalence of the E over the Z form is unambiguously provided [K300 = [E] / [Z] = 2.86(2) and 9.63(5) for NMAH and NMA−, respectively], closing thereby a long-lasting dispute about the most stable conformer. To that end, calculations of the chemical shifts by density functional theory (DFT), which accurately reproduced the experimental data, turned out to be a much more reliable method than the direct computation of the relative energy for each conformer. The Z ⇌ E interconversion dynamics was probed at 300 K in D2O by 2D exchange-correlated spectroscopy (EXSY), affording the associated rate constants [kZE = 9.0(2) s− 1 and kEZ = 3.14(5) s− 1 for NMAH, kZE = 0.96(3) s− 1 and kEZ = 0.10(2) s− 1 for NMA−] and activation barriers at 300 K [ΔG≠ZE = 68.0 kJ mol− 1 and ΔG≠EZ = 70.6 kJ mol− 1 for NMAH, ΔG≠ZE = 73.6 kJ mol− 1 and ΔG≠EZ = 79.2 kJ mol− 1 for NMA−]. For the first time, mono- and bis-chelated uranium(VI) complexes of NMA− have been isolated. Crystals of [UO2(NMA)(NO3)(H2O)2] and [UO2(NMA)2(H2O)] have been characterized by X-ray diffractometry, infrared and Raman spectroscopies

1,3-Dipolar Cycloaddition of Ethyl Diazoacetate with (E)-3-Arylidenechroman-4-ones. A New Access to Spirocyclopropane Derivatives

International audience(E)-3-Arylidenechroman-4-ones 1a–e (Ar = Ph, p-MeC6H4, p-MeOC6H4, p-MeSC6H4, p-ClC6H4) react regioselectively (100%) with ethyl diazoacetate 2 in refluxing toluene to afford in good yields spiro-Δ2-pyrazolines ethyl 4’-oxo-4-aryl-spiro[chromanone-3’,5-pyrazole]-3-carboxylate 3a–e. The occurrence of Δ1-pyrazolines as reaction intermediates has been evidenced. The regio- and stereochemistry of spiranic compounds 3a-e has been established on the basis of spectroscopic data and elemental analyses, corroborated by a single crystal X-ray crystallographic analysis of one product 3a. The spiro-adducts 3a–e were brominated by NBS to give spirocyclic-substituted 3-bromo-4,5-dihydro-3H-pyrazoles 4a–e. The latter compounds evolve straightforwardly N2 in refluxing toluene to afford substituted spirocyclic 1-bromocyclopropane-1-carboxylates. The molecular structure of cyclopropane derivative 5e has been determined by means of a single-crystal X-ray diffraction study

Regio- and Stereoselective Synthesis of Spiropyrrolizidines and Piperazines through Azomethine Ylide Cycloaddition Reaction

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