Synthesis of 4‑Silapiperidine Building Blocks with N–H Groups Using the Staudinger Reaction

4-Silapiperidines are important skeletons for drug design. In this context, a novel acid-free method for the synthesis of 4-silapiperidine building blocks with N–H groups has been developed, using the Staudinger reaction as the key step. As a proof of principle, the model compounds <b>13</b> and <b>14</b> were synthesized, starting from Ph₂SiCl₂ and MeSi­(OMe)₃, respectively

Mean effects of outbreeding on resistance and tolerance.

<p>Average resistance, measured as a) 1- proportion of damaged leaf area, b) final snail mass in the snail herbivory experiment with plants resulting from two generations of within- and between-population crosses of plants from 13 populations of <i>Lychnis flos-cuculi</i>. c) Effects of outbreeding on tolerance to clipping in the clipping experiment with plants resulting from two generations of within- and between-population crosses of plants from 19 populations of <i>Lychnis flos-cuculi</i>. Average effects of clipping on number of fruits produced after damage (1c). Covariate-adjusted least-squares means estimates and estimated standard errors are presented.</p

Outbreeding effects on tolerance to snail and artificial damage.

<p>ANCOVA summary of a) effects of populations, cross (with or between population outbreeding) and artificial damage (clipped and sprayed versus undamaged) on the number fruits produced after damage in our artificial-damage experiment and b) effects of populations, cross, family and level of snail damage on the number of fruits produced after damage in our snail herbivory experiment.</p

Plant Metabolomics: Maximizing Metabolome Coverage by Optimizing Mobile Phase Additives for Nontargeted Mass Spectrometry in Positive and Negative Electrospray Ionization Mode

Nontargeted screening methods with ultrahigh-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight mass spectrometry have been extensively applied to plant metabolomics to very diverse scientific issues in plant metabolomics. In this study, different mobile phase additives were tested in order to improve the electrospray ionization process and to detect as many metabolites as possible with high peak intensities in positive and negative ionization mode. Influences of modifiers were examined for nonpolar and polar compounds, as optimal conditions are not always the same. By combining different additives, metabolite coverage could be significantly increased. The best results for polar metabolites in positive ionization mode were achieved by using 0.1% acetic acid and 0.1% formic acid in negative ionization mode. For measurements of nonpolar metabolites in positive ionization mode, the application of 10 mmol/L ammonium formate led to the best findings, while the use of 0.02% acetic acid was more appropriate in negative ionization mode

Effects of past herbivory and pathogen infection levels on PR protein activity in Ragged Robin.

<p>Constitutive CHT activities for plants from the 13 Ragged Robin populations a) in relation to levels of pathogen infection in the populations and b) inbreeding effects on CHT in relation to levels of herbivory in the populations. The gray dots denote population means for experimentally inbred plants and black dots denote population means for experimentally outbred plants (2b).</p

The effects of experimental inbreeding (cross) and past levels of pathogen and herbivore damage on constitutive activities of β-1,3-glucanases (GLU) and chitinases (CHT) in plants from 13 Ragged Robin populations.

<p>The effects of experimental inbreeding (cross) and past levels of pathogen and herbivore damage on constitutive activities of β-1,3-glucanases (GLU) and chitinases (CHT) in plants from 13 Ragged Robin populations.</p

Inbreeding effects on PR protein activity in Ragged Robin.

<p>Effect of experimental inbreeding on constitutive activity of a) chitinases (CHT) and b) β-1,3-glucanases (GLU). Variation in c) CHT and d) GLU activities among plants from the 13 investigated populations. Enzyme activities are expressed as average values (± standard error) across the populations (1a, 1b) or per population and cross (1c, 1d) in increase of absorbance at 600 and 550 nm per mg protein and per min ×1000 (GLU and CHT, respectively).</p

Appendix A. A table showing populations of origin of seeds of Lychnis flos-cuculi used in the greenhouse experiment.

A table showing populations of origin of seeds of Lychnis flos-cuculi used in the greenhouse experiment

Synthesis of 4‑Silacyclohexan-1-ones and (4-Silacyclohexan-1-yl)amines Containing the Silicon Protecting Groups MOP (4-Methoxyphenyl), DMOP (2,4-Dimethoxyphenyl), or TMOP (2,4,6-Trimethoxyphenyl): Versatile Si- and C‑Functional Building Blocks for Synthesis

The 4-silacyclohexanones <b>1</b>–<b>6</b> were prepared in convenient multistep syntheses, starting from MeSi­(OMe)₃ and PhSi­(OMe)₃, respectively. Cleavage of the 4-methoxyphenyl (MOP), 2,6-dimethoxyphenyl (DMOP), and 2,4,6-trimethoxyphenyl (TMOP) protecting groups of <b>4</b>–<b>6</b> by treatment with HCl/Et₂O in CH₂Cl₂ at 20 °C gives the 4-chloro-4-silacyclohexanone <b>13</b>. Reductive amination of <b>1</b>–<b>6</b> with NH₃ or <i>i</i>-PrNH₂ yields the respective (4-silacyclohexan-1-yl)­amines <b>7</b>–<b>12</b>. Compounds <b>1</b>–<b>12</b> and all new precursors synthesized were characterized by elemental analyses (C, H, N) or mass spectrometric investigations (ESI-HRMS) and by NMR spectroscopic studies (¹H, ¹³C, ²⁹Si). Compounds <b>1</b>, <b>3</b>, <b>5</b>, and <b>6</b> and the precursors (MeO)₂SiPh­(TMOP) (<b>21</b>) and (CH₂CH)₂SiPh­(TMOP) (<b>27</b>) were additionally characterized by single-crystal X-ray diffraction. Compounds <b>1</b>–<b>12</b> with their Si- and C-functional groups represent versatile building blocks for synthesis

Loop-Mediated Isothermal Amplification (LAMP)-Based Method for Rapid Mushroom Species Identification

Toxic mushroom species, such as the death cap (Amanita phalloides), are responsible for most mushroom poisonings. In the present work, novel loop-mediated isothermal amplification (LAMP) assays were used for the differentiation of even closely related edible and toxic mushroom species. The applicability of these methods was tested by cross-reaction studies and analysis of spiked mushroom samples (raw and fried material). Contaminations at the level of 2% (w/w) could be detected in different mushroom blends. Three detection methods were used: agarose gel analysis, fluorimetric real-time detection, and visual detection by lateral flow dipsticks (LFD). The LAMP assay combined with LFD detection allows the identification of A. phalloides in about 2 h (including DNA extraction) at a very low level of technical equipment (micropestle, water bath, and mobile centrifuge), which makes this technique perfectly suited for on-site applications