Synthesis, fungicidal activity and molecular docking of novel pyrazole-carboxamides bearing a branched alkyl ether moiety.

Succinate dehydrogenase inhibitors are essential fungicides used in agriculture. To explore new pyrazole-carboxamides with high fungicidal activity, a series of N-substitutedphenyl-3-di/trifluoromethyl-1-methyl-1H-pyrazole-4-carboxamides bearing a branched alkyl ether moiety were designed and synthesized. The in vitro bioassay indicated that some target compounds displayed appreciable fungicidal activity. For example, compounds 5d and 5e showed high efficacy against S. sclerotiorum with EC50 values of 3.26 and 1.52 µg/mL respectively, and also exhibited excellent efficacy against R. solani with EC50 values of 0.27 and 0.06 µg/mL respectively, which were comparable or superior to penflufen. The further in vivo bioassay on cucumber leaves demonstrated that 5e provided strong protective activity of 94.3 % against S. sclerotiorum at 100 µg/mL, comparable to penflufen (99.1 %). Cytotoxicity assessment against human renal cell lines (239A cell) revealed that 5e had low cytotoxicity within the median effective concentrations. Docking study of 5e with succinate dehydrogenase illustrated that R-5e formed one hydrogen bond and two π-π stacking interactions with amino acid residues of target enzyme, while S-5e formed only one π-π stacking interaction with amino acid residue. This study provides a valuable reference for the design of new succinate dehydrogenase inhibitor.

Combination of structure-performance and shape-performance relationships for better biphasic release in electrospun Janus fibers.

In nature, the combination of composition, structure, and shape determines the matter's functional performance to a large extent. Inspired by which, two electrospun Janus nanofiber formulations were created using side-by-side electrospinning in this work. Tamoxifen citrate (TAM) was used as a model drug and ethyl cellulose (EC) and polyvinylpyrrolidone K60 (PVP) as the polymer carrier matrices. The fibers have linear cylindrical morphologies and distinct Janus structures by scanning electron microscopy. One side of the fibers took a round shape, while the other was crescent-shaped. The drug was present in both polymer matrices in the form of amorphous solid dispersions, owing to strong intermolecular interactions between drug and polymer. In vitro dissolution tests demonstrated that both sets of fibers could provide biphasic drug release due to the difference in solubility of PVP and EC. The different shape of TAM-EC and TAM-PVP side of the Janus structure resulted in a considerable variation in the drug release profiles. The Janus structure with crescent TAM-PVP side and round TAM-EC side gave a more rapid burst release in the first phase of release, and slower sustained release in the second phase. This work thus reports a new strategy for systematically developing advanced functional nanomaterials based on both shape- and structure-performance relationships.

Comparative study of electrospun crystal-based and composite-based drug nano depots.

Complex nanostructures are increasingly becoming important in the development of novel functional nanomaterials. Nano drug depots, characterized by core-shell structures with core drug reservoirs, are drawing increasing attention because of its potential applications in furnishing drug-sustained release profiles. In the present study, two kinds of nano drug depots, one containing a crystal drug reservoir and the other having a medicated composite drug reservoir, were prepared through modified triaxial electrospinning. Their drug-sustained release performances were compared in terms of initial burst release, middle linear release, and the late tailing off release. Although both depots had a linear morphology, clear core-shell nanostructures and the same cellulose acetate shell layer, they provided considerably different tailing off release performances, and thus different sustained release profiles. The composite-based drug depots showed a smaller tailing off drug amount of 2.2%, a shorter time period of 12 h, and a better zero-order controlled release kinetics in general than the crystal-based drug depots, whose tailing off amount was 9.3% over a time period of 36 h. The mechanism was proposed, which had a close relationship with the state of drug in the core reservoir. The present protocols open a new way for producing medicated structural nanomaterials.

Efficient alkaloid capture from water using a charged porous organic polymer.

Berberine hydrochloride (BH), an important alkaloid, can be captured from water and released in organic solution circularly by a charged porous polymer (TPB-HCP), which is hypercross-linked using the cost-effective Friedel-Crafts reaction using sodium tetraphenylborate as the monomer. With high BET surface area, hierarchical porous structure and charged characteristics, TPB-HCP displays excellent adsorption capacity for BH owing to the synergistic effects of size matching and electrostatic interaction.

[Synthesis, characterization and relaxivity of dimeric DTPA-gadonium (III) complexes with long chain alkyl esters of L-lysine].

To look for new MRI (magnetic resonance imaging) contrast agents with higher relaxivity as well as liver-selecsivity, four novel ester-amino ligands were synthesized by bis-acylation of octadecanyl, hexadecanyl, tetradecanyl and dedecanyl L-lysine with diethylenetriaminepentaacetic acid mono-anhydride (DTPA-MA), respectively. The corresponding dimeric Gd(III) complexes were gained by the reaction of these ligands with GdCl3 x 6H2O. All ligands and complexes were characterized by FTIR, 1H NMR and elemental analysis. The longitudinal relaxation time (T1) was measured, and relevant longitudinal relaxivity (R1) of these neatral binuclear Gd(III) complexes is: 6.48, 6.02, 5.76 and 5.68 L x mmol(-1) x s(-1), respectively, and all are higher than that of Gd-DTPA (4.98 L x mmol(-1) x s(-1)) (300 MHz).