Nanoscale imaging and characterization of Caenorhabditis elegans epicuticle using atomic force microscopy

© 2016 Elsevier Inc.Here we introduce PeakForce Tapping non-resonance atomic force microscopy for imaging and nanomechanical mapping of Caenorhabditis elegans nematodes. The animals were imaged both in air and water at nanoscale resolution. Layer-by-layer glass surface modification was employed to secure the worms for imaging in water. Microtopography of head region, annuli, furrows, lateral alae and tail region was visualized. Analysis of nanoscale surface features obtained during AFM imaging of three larval and adult hermaphrodite nematodes in natural environment allowed for numerical evaluation of annuli periodicity, furrows depth and annuli roughness. Nanomechanical mapping of surface deformation, Young modulus and adhesion confirms that the mechanical properties of the nematode cuticle are non-uniform. Overall, PeakForce Tapping AFM is a robust and simple approach applicable for nanoscale three-dimensional imaging and characterization of C. elegans nematodes

Reactions of Pyridoxal with Heterocycles Containing Primary Amino Group

© 2018, Pleiades Publishing, Ltd. New nitrogen-containing derivatives of pyridoxal were obtained as a result of its reaction with various amines. The reactions with amines bearing a heterocyclic fragment (pyridine, pyrimidine, quinoline, piperidine) furnished the final products stabilized in an aminoacetal form. The product prepared from 2-aminomethylpiperidine has an imidazolidine fragment in the molecule

Reaction of pyridoxal and its azomethines with hydrophosphoryl compounds

© 2016 Taylor & Francis Group, LLC.The products of carbonyl phosphonylation of pyridoxal with alkylphosphinic acid ethyl esters, phosphorous acid dialkyl esters have been obtained for the first time. In some cases, the products of addition are hydrolytically unstable and stabilize by forming internal betaine structures. The reaction of pyridoxal with phosphorous acid in alcohol solutions gives alkoxyfuropyridines possessing the iminium nitrogen atom

Reactions of pyridoxal with aromatic carboxylic acids in alcoholic medium

© 2017, Pleiades Publishing, Ltd. Reactions of pyridoxal with benzoic acid and its derivatives in alcoholic medium afforded alkoxyfuropyridinium salts with potential biological activity

Pyridoxal reactions with amines and aliphatic diamines

© 2016, Pleiades Publishing, Ltd.Interaction of pyridoxal (3-hydroxy-5-hydroxymethyl-2-methylisonicotinaldehyde) with amines, mono- and disubstituted diamines led to the formation of compounds having in their structure imine, imidazolidine, and pyrimidine moieties. Structure of the obtained compounds was proved by IR data, 1H NMR spectroscopy, mass spectrometry, and X-ray diffraction analysis

2-(2-Hydroxyphenyl)imidazolidines and their O-phosphorylated derivatives

© 2017, Pleiades Publishing, Ltd. 2-(2-Hydroxyaryl)imidazolidines were synthesized by reaction of aromatic carbonyl compounds with N,N′-dialkylethylenediamines. The title compounds were also prepared using the corresponding Schiff bases instead of carbonyl compounds. Phosphorylation of 2-(2-hydroxyphenyl)imidazolidines with phosphoryl and phosphorothioyl chlorides and phosphorochloridites was accomplished. The reaction of O-phosphorylsalicylaldehyde with N,N′-dialkylethylenediamines also afforded 2-(2-hydroxyphenyl)imidazolidines

Phosphorus containing azomethines and furopyridines on the basis of pyridoxal

© 2016 Taylor & Francis Group, LLC.New O-phosphorylated pyridoxal derivatives, based on the azomethine reaction with acid chlorides P(IV) were synthesized. Depending on the nature of the substituent on the nitrogen atomfinal products are phosphorylated furopyridines or azomethines of pyridoxal

Synthesis of novel macrocyclic ligands containing phosphoryl and aminoacetal fragments

A method for the synthesis of novel phosphorylated aminoacetals was developed. The latter are involved in Mannich reaction as amine component with calix[4]resorcinol and formaldehyde to form tetrasubstituted macrocycles containing four acetal groups and four phosphonate (phosphine oxide) fragments on the "upper" rim of molecule with high yields. © 2013 Copyright Taylor and Francis Group, LLC

Nanoscale imaging and characterization of Caenorhabditis elegans epicuticle using atomic force microscopy

© 2016 Elsevier Inc.Here we introduce PeakForce Tapping non-resonance atomic force microscopy for imaging and nanomechanical mapping of Caenorhabditis elegans nematodes. The animals were imaged both in air and water at nanoscale resolution. Layer-by-layer glass surface modification was employed to secure the worms for imaging in water. Microtopography of head region, annuli, furrows, lateral alae and tail region was visualized. Analysis of nanoscale surface features obtained during AFM imaging of three larval and adult hermaphrodite nematodes in natural environment allowed for numerical evaluation of annuli periodicity, furrows depth and annuli roughness. Nanomechanical mapping of surface deformation, Young modulus and adhesion confirms that the mechanical properties of the nematode cuticle are non-uniform. Overall, PeakForce Tapping AFM is a robust and simple approach applicable for nanoscale three-dimensional imaging and characterization of C. elegans nematodes