Construction of Complex 1,3-Cyclohexadienes via Phosphine-Catalyzed (4 + 2) Annulations of δ‑Acetoxy Allenoates and Ketones

The phosphine-catalyzed substrate-dependent (4 + 2) annulations of δ-acetoxy allenoates with ketones is described. Allenoates <b>1</b> with an alkyl substituent at δC are able to react with cyclic 1,3-diketones <b>2</b>, wherein the δC is attacked by the methenyl carbon of <b>2</b> while the αC attacks the ketone of <b>2</b>. Allenoates <b>5</b> with an aryl group at δC is poised to react with cyclic β-carbonyl amides <b>6</b>, in which the αC is attacked by the methenyl carbon of <b>6</b> and the δC undergoes 1,2-addition to the ketone of <b>6</b>

Steam Reforming of Coke Oven Gas for Hydrogen Production over a NiO/MgO Solid Solution Catalyst

The steam reforming of coke oven gas (COG) for hydrogen production was investigated over the NiO/MgO solid solution catalysts reduced at high temperatures. It was found that the NiO/MgO catalyst possessed good catalytic activity, and the conversions of CH₄ and CO₂ were greatly affected by the reaction temperature and steam/carbon (S/C) mole ratio. During the tested period of 100 h under a low S/C ratio of 1.0 at 875 °C, the conversions of CH₄ and CO₂ kept constant values around 97.6 and 44.3%, respectively, and the hydrogen volume content was enhanced from 58.2% in the original COG to 77.7% by 1.5 times. The catalyst characterization results of X-ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetry (TG) after the reaction showed that the Ni nanoparticle sizes had a slight increase and the amount of the coke deposition was ca. 1%. These results showed that the NiO/MgO catalyst was efficient and stable for the steam reforming of COG to amplify hydrogen in COG. This research will be of importance in hydrogen production from COG

Glyphosate tolerance of transgenic tobacco plants in a greenhouse when sprayed with 6 L ha⁻¹ Roundup®.

<p>T1 tobacco seeds were germinated on the MS medium containing 10 mg L⁻¹ PPT and grown for 7 days at 100 µmol s⁻¹ m⁻² with a 16 h light/8 h dark period. The live seedlings were transferred to soil in pots and grown for another month. Six-to eight-leaf stage transgenic plants were sprayed with 6 L ha⁻¹ Roundup®. Two weeks after treatment, injury was observed, and survival rate was measured. (A) Photograph of tobacco plants two weeks after glyphosate treatment. (B) Survival rate of tobacco plants. Data are shown as the average ± S.E. of seven to ten independent transgenic lines. Experimental data was tested by ANOVA analysis and different letter in each column means significant difference at <i>P</i><0.05 level.</p

Glyphosate tolerance of transgenic tobacco seedlings on plates containing 1 mM glyphosate.

<p>T1 tobacco seeds were germinated on the MS medium containing 10 mg L⁻¹ PPT and grown for 7 days. The live seedlings were transferred to MS medium on plates containing 1 mM glyphosate. Photographs were taken two weeks later, and the fresh weight was measured at the same time. (A) Photograph of tobacco harboring <i>HTG7 aroA</i> and WT grown on the medium containing 1 mM glyphosate. (B) Photograph of tobacco harboring <i>AM79 aroA</i> and WT grown on the medium containing 1 mM glyphosate. (C) Photograph of tobacco harboring <i>A1501 aroA</i> and WT grown on the medium containing 1 mM glyphosate. (D) Photograph of tobacco harboring <i>RD aroA</i> and WT grown on the medium containing 1 mM glyphosate. (E) Photograph of tobacco harboring <i>G2 aroA</i> and WT grown on the medium containing 1 mM glyphosate. (F) Photograph of tobacco plants grown on the medium without glyphosate. (G) Fresh weight of the tobacco plants. Data are shown as the average ± S.E. of seven to ten independent transgenic lines. Experimental data was tested by ANOVA analysis and different letter in each column means significant difference at <i>P</i><0.05 level.</p

Glyphosate tolerance of <i>E. coli</i> containing five <i>aroA</i> genes.

<p>The plasmids pACYC184, pACYC-HTG7, pACYC-AM79, pACYC-A1501, pACYC-RD and pACYC-G2 were transformed into <i>E. coli</i> ER2799 competent cells for growth curve measurement. M9 liquid medium was supplemented with different concentrations of glyphosate. OD₆₀₀ was recorded every two hours starting 6 h after treatment. Data are shown as the average ± S.E. of three independent experiments. Experimental data was tested by ANOVA analysis and different letter means significant difference at <i>P</i><0.05 level. (A) Growth curve of ER2799 and the strain harboring different plasmids under 0 mM glyphosate. (B) Growth curve of ER2799 and the strain harboring different plasmids under 20 mM glyphosate. (C) Growth curve of ER2799 and the strain harboring different plasmids under 100 mM glyphosate. (D) Growth curve of ER2799 and the strain harboring different plasmids under 150 mM glyphosate. (E) Growth curve of ER2799 and the strain harboring different plasmids under 200 mM glyphosate.</p

Southern blot analysis of transgenic tobacco plants.

<p>(A) HTG7; (B) AM79; (C) A1501; (D) RD; (E) G2. Five transgenic lines each construct were analyzed. 100 µg genomic DNA was digested with <i>Hin</i>dIII which has only one site in the plasmid, so the band numbers are equal to the copy number of transgene.</p

T-DNA cassette containing <i>aroA</i> gene for plant transformation.

<p>LB and RB, left and right border of T-DNA; bar, phosphinothricin acetyltransferase gene; nos, <i>NOS</i> terminator; CaMV 35S, cauliflower mosaic virus 35S promoter; SP, coding sequence of signal peptide of pea rib-1,5-bisphospate carboxylase (<i>rbcS</i>) small subunit; EPSPS gene, five microorganism <i>aroA</i> gene.</p

Phylogenetic analysis of the five EPSPS and related proteins.

<p>The phylogenetic tree was based on homologous sequences of the EPSPS proteins and the neighbor-joining methods (MEGA4.0). The percentage of the tree from 1000 bootstrap resamples supporting the topology is indicated when above 50. Accession numbers or international patent publication numbers are shown in parentheses. The scale bar represents 0.1 substitutions per position.</p

Glyphosate tolerance of transgenic tobacco under different glyphosate concentrations.

<p>Tobacco seeds of generation T1 were germinated on the MS medium containing 10 mg L⁻¹ PPT and grown for 7 days at 100 µmol s⁻¹ m⁻² with a 16 h light/8 h dark period. The live seedlings were transferred to MS medium in plates containing different amounts of glyphosate and grown vertically for another two weeks.</p