Highly Selective and Reversible Chemosensor for Pd²⁺ Detected by Fluorescence, Colorimetry, and Test Paper

A “turn-on” fluorescent and colorimetric chemosensor (<b>RBS</b>) for Pd²⁺ has been designed and synthesized through introduction of sulfur as a ligand atom to Rhodamine B. <b>RBS</b> exhibits high selectivity (freedom from the interference of Hg²⁺in particular) and sensitivity toward Pd²⁺ with a detection limit as low as 2.4 nM. <b>RBS</b> is also a reversible sensor, and it can be made into test paper to detect Pd²⁺ in pure water. Compared to the chemosensors that introduced phosphorus to Rhodamine to detect Pd²⁺, <b>RBS</b> can be synthesized more simply and economically

Theoretical and Experimental Studies on Plant Light-Dependent Protochlorophyllide Oxidoreductase as a Novel Target for Searching Potential Herbicides

Herbicide resistance is a prevalent problem that has posed a foremost challenge to crop production worldwide. Light-dependent enzyme NADPH: protochlorophyllide oxidoreductase (LPOR) in plants is a metabolic target that could satisfy this unmet demand. Herein, for the first time, we embarked on proposing a new mode of action of herbicides by performing structure-based virtual screening targeting multiple LPOR binding sites, with the determination of further bioactivity on the lead series. The feasibility of exploiting high selectivity and safety herbicides targeting LPOR was discussed from the perspective of the origin and phylogeny. Besides, we revealed the structural rearrangement and the selection key for NADPH cofactor binding to LPOR. Based on these, multitarget virtual screening was performed and the result identified compounds 2 affording micromolar inhibition, in which the IC50 reached 4.74 μM. Transcriptome analysis revealed that compound 2 induced more genes related to chlorophyll synthesis in Arabidopsis thaliana, especially the LPOR genes. Additionally, we clarified that these compounds binding to the site enhanced the overall stability and local rigidity of the complex systems from molecular dynamics simulation. This study delivers a guideline on how to assess activity-determining features of inhibitors to LPOR and how to translate this knowledge into the design of novel and effective inhibitors against malignant weed that act by targeting LPOR

Synthesis of the title compounds k/l.

<p>Synthesis of the title compounds k/l.</p

Key COSY (bold) and HMBC (arrows) correlations in l8.

<p>Key COSY (bold) and HMBC (arrows) correlations in l8.</p

Design strategy for target compounds.

<p>Design strategy for target compounds.</p

The target name, the PDB ID and fit score of 22 compounds.

<p>The target name, the PDB ID and fit score of 22 compounds.</p

COMFA and COMSIA analysis results^*.

<p>COMFA and COMSIA analysis results^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181646#t002fn001" target="_blank">*</a>}.</p

Synthesis, fungicidal evaluation and 3D-QSAR studies of novel 1,3,4-thiadiazole xylofuranose derivatives - Fig 7

<p>Contour plots (a) CoMSIA Steric. (b) CoMFA Electrostatic. (c) CoMSIA Steric. (d) CoMSIA Electrostatic. (e) CoMSIA Hydrophobic. (f) CoMSIA Hydrogen bond receptor. Compound k8 in cap and stick is shown.</p

EC₅₀ and EC₉₀ values of target compounds against S. sclerotiorum.

<p>EC₅₀ and EC₉₀ values of target compounds against S. sclerotiorum.</p