Thin-Layer Chromatography of Metal Cations Modified with Amines and Surfactants and the Sorption-Catalytic Detection of Cobalt(II) and Copper(II)

JPC – Journal of Planar Chromatography – Modern TLC - The thin-layer chromatography (TLC) procedures of metal cations, modified with amines and cationic surfactant micelles, followed by...     

Effect of Impregnation Conditions on the Structure and Chromatographic Behavior of TLC Adsorbents Modified with Cu(II) and Ni(II) Salts

JPC – Journal of Planar Chromatography – Modern TLC - Attempts have been made to find the optimum conditions for modification of silica gel and amino- and cyanopropyl-bonded silica with...     

Thin-Layer Chromatographic Analysis of Glucose,Maltose, and Raffinose in Biomphalaria glabrata (Gastropoda) Infected with Echinostoma caproni (Trematoda)

JPC – Journal of Planar Chromatography – Modern TLC -     

Synthesis and Characterization of Bis(2‐iminopyrrolyl) Iron(II) Complexes by N–H Bond Activation

The reactions of 2‐iminopyrroles 1 – 3 with Fe(PMe₃)₄ afforded the N–H activated bis(2‐iminopyrrolyl) iron(II) complexes 4 – 6 . The structures of compounds 4 – 6 were determined by single‐crystal X‐ray diffraction. The formation mechanism of complexes 4 – 6 was discussed.     

Densitometric Quantification of Monogalactosyldiacylglycerol (MGDG) and Digalactosyldiacylglycerol (DGDG) in Extracts of Fresh Samples of Erigeron canadensis Collected at Different Stages of Growth

JPC – Journal of Planar Chromatography – Modern TLC - Erigeron canadensis is an annual plant of the Asteraceae family, widely distributed in rural and urban areas of Poland and other...     

Validated Densitometric TLC Method for Analysis of (R)- and (S)-Bupivacaine,Using Cyclodextrin Derivatives as Chiral Selectors

JPC – Journal of Planar Chromatography – Modern TLC - Anovel economic procedure for stereospecific separation and analysis of (R)-and (S)-bupivacaine has been developed and validated....     

Thin-Layer Chromatography of Quinolones in Ion-Association Systems with Di(2-Ethylhexyl)Orthophosphoric Acid (HDEHP)

JPC – Journal of Planar Chromatography – Modern TLC - Quinolones, because of their hydrophilic (amphiionic) character, are strongly adsorbed by silica even from polar solvents. It has...     

Adsorption of Zinc(II) and Cadmium(II) on Soil Layers in TLC in the Presence of Surfactant-Containing Mobile Phases

JPC – Journal of Planar Chromatography – Modern TLC - Adsorption of Zn(II) and Cd(II) ions on soil TLC plates was studied using aqueous solutions of surfactants as mobile phases. The...     

Hydroalumination‐Brominolysis of Vinylalkynols: A Novel Entry to (E)‐ and (Z)‐Bromoalkadienols,and Bromoallenols

Hydroalumination‐brominolysis of vinylacetylenic alcohols 1 – 4 provides a novel entry to synthetically useful (E)‐ and (Z)‐bromoalkadienols, and bromoallenols, which are otherwise hardly accessible. An electrophilic cleavage of cyclic intermediate A follows competing mechanistic pathways, giving rise to isomeric (Z)‐bromodienols 5 – 8 and allenic alcohols 9 – 12 . The latter are stereoselectively converted to (E)‐bromoalkadienols 13 – 16 by CuBr‐catalyzed anionotropic rearrangement.     

Lanthanide(III) Bis(phthalocyaninato)–[60]Fullerene Dyads: Synthesis,Characterization, and Photophysical Properties

A novel series of double‐decker lanthanide(III) bis(phthalocyaninato)–C₆₀ dyads [Ln^III(Pc)(Pc′)]–C₆₀ (M=Sm, Eu, Lu; Pc=phthalocyanine) ( 1 a – c ) have been synthesized from unsymmetrically functionalized heteroleptic sandwich complexes [Ln^III(Pc)(Pc′)] (Ln=Sm, Eu, Lu) 3 a – c and fulleropyrrolidine carboxylic acid 2 . The sandwich complexes 3 a – c were obtained by means of a stepwise procedure from unsymmetrically substituted free‐base phthalocyanine 5 , which was first transformed into the monophthalocyaninato intermediate [Ln^III(acac)(Pc)] and further reacted with 1,2‐dicyanobenzene in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU). ¹H NMR spectra of the bis(phthalocyaninato) complexes 3 a – c and dyads 1 a – c were obtained by adding hydrazine hydrate to solutions of the complexes in [D₇]DMF, a treatment that converts the free radical double‐deckers into the protonated species, that is, [Ln^III(Pc)(Pc′)H] and [Ln^III(Pc)(Pc′)H]–C₆₀. The electronic absorption spectra of 3 a – c and 1 a – c in THF exhibit typical transitions of free‐radical sandwich complexes. In the case of dyads 1 a – c , the spectra display the absorption bands of both constituents, but no evidence of ground‐state interactions could be appreciated. When the UV/Vis spectra of 3 a – c and 1 a – c were recorded in DMF, typical features of the reduced forms were observed. Cyclic voltammetry studies for 3 a – c and 1 a – c were performed in THF. The electrochemical behavior of dyads 1 a – c is almost the exact sum of the behavior of the components, namely the double‐decker [Ln^III(Pc)(Pc′)] and the C₆₀ fullerene, thus confirming the lack of ground‐state interactions between the electroactive units. Photophysical studies on dyads 1 a – c indicate that only after irradiation at 387 nm, which excites both C₆₀ and [Ln^III(Pc)(Pc′)] components, a photoinduced electron transfer from the [Ln^III(Pc)(Pc′)] to C₆₀ occurs.     

Identification of lysophosphatidylcholine (LPC) and platelet activating factor (PAF) from PC12 cells and mouse cortex using liquid chromatography/multi-stage mass spectrometry (LC/MS3)

Lipids play essential roles in cellular structural support, energy storage and signal transduction. Recently, mass spectrometry (MS) has been used to produce three-dimensional maps that elucidate the lipid composition of complex cellular lysates. The identification of individual lipids within these maps is slow and requires the synthesis and spiking of each candidate lipid. We present a novel MS-based technique that rapidly elucidates the atomic connectivity of the fatty acid/alcohol substituent on the sn-1 position of several different families of glycerophosphocholine-containing lipids within the confines of a chromatographic separation. Sodiated lipid species were fragmented to produce radical cations which lost successive methylene groups upon further collisional activation to reveal the identity of the parent molecule. This approach was demonstrated to be effective on isobaric members of the lysophosphatidylcholine (LPC) and platelet activating factor (PAF) families of glycerophospholipids. We demonstrate the application of this technique to unambiguously identify these species within complex cellular lysates and tissue extracts.     

Electrochemical Oxidation of Bis(methylthio)benzenes

The bis(methylthio)benzenes 3a – 3c are oxidized to the methylsulfinyl-methylthiobenzenes 4a – 4c on a Pt-anode in good yields.     

Separation and Quantitative Determination of Aldoses and Alditols by Over-Pressured Layer Chromatography (OPLC)

JPC – Journal of Planar Chromatography – Modern TLC - Anew OPLC method has been established for separation and quantitative determination of three alditols (d-xylitol, L-arabitol, and...     

Professor Jan Krzek (1946–2015)

JPC – Journal of Planar Chromatography – Modern TLC -     

The Effect of the Substituents of β-Ketoiminato Ligand of Copper(II) and Nickel(II) Complexes on their Retention on Thin Layers of Polyacrylonitrile

JPC – Journal of Planar Chromatography – Modern TLC - The effect of substituents of the β-ketoiminato ligand of 24 cop-per(H) and nickel(H) complexes on hRF values obtained by TLC...     

Determination of Fe(II) and Zn(II) in Vitrum Prenatal by Ion Chromatography (IC). Comparison with Classical and Derivative Spectrophotometry (D0, D1, and D2) with Metrian,Metriap, Metriarez-γ, and Metidarez-β Dyes and with Atomic Absorption Spectrometry

JPC – Journal of Planar Chromatography – Modern TLC - 3-Mercapto-5-(2′-hydroxynaphthylazo-1′)-1,2,4-triazole (metrian);...     

Separation of Complex Fructo-Oligosaccharides (FOS) and Inulin Mixtures by HPTLC–AMD

JPC – Journal of Planar Chromatography – Modern TLC - A first attempt at the separation of fructo-oligosaccharides (FOS) and inulin mixtures is presented. Preliminary results obtained...     

Synthese und Strukturbestimmung von (i-Pr)2NB(t-BuP)3 und (i-Pr)2NB(t-BuP)4

Synthesis and Structure Analysis of (i-Pr)₂NB(t-BuP)₃ and (i-Pr)₂NB(t-BuP)₄ The diphosphide K(t-Bu)P-(t-BuP)₂-P(t-Bu)K obtained by the cleavage reaction of the 3-membered ring system (i-Pr)₂BN(t-BuP)₂ with potassium reacts with t-BuPCl₂ at ?78°C under ring expansion to form the P₃B ring system (i-Pr)₂NB(t-BuP)₃ – 1,2,3-tri-t-butyl-tri-phospha-4-diisopropyl-aminoboretane ( 1 ). – The 5-membered P₄B ring system (i-Pr)₂NB(t-BuP)₄ – 1,2,3,4-tetra-t-butyl-tetraphospha-5-diisopropylaminoborolidine, ( 2 ) – is formed from K(t-Bu)P? (t-BuP)₂? P(t-Bu)K and (i-Pr)₂NBCl₂ analogous to the above reaction. 1 and 2 could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analysis. 1 shows at 200 K two conformation isomers; for 2 ³¹P-^10,11B-isotopic shifts could be identified.     

Influence of the Axial Alkyl Ligand on the Reduction Potential of Alkylcob(III)alamins and Alkylcob(III)yrinates

The irreversible-reduction potentials of 26 alkylcob(III)alamins (RCbl^III 1a – z ) and 26 alkylcob(III)yrinates (R‘Cby’^III; 2a – z ) (E_p 1a – z and E_p 2a – z , resp.) have been measured in situ by single-scan voltammetry of hydroxocob(III)alamin hydrochloride (vitamin B_12b- HCl; 1 ) or heptamethyl cob(II)yrinate perchlorate (ClO₄‘Cby’^II; 2 ) in presence of the corresponding alkyl halides (RX; 3a – z ) in DMF. The reduction potentials of alkylcobalt complexes exhibiting half-life times as short as a few seconds become measurable by this technique. Thermodynamic cycles prove that the observed reduction potentials are closely related to the standard reduction potentials E°(R? Co^III + e^??R? + Co^I). Electron-withdrawing groups and/or an increased degree of substitution at the Co-bound C-atom in RCbl^III and, R‘Cby’^III shift E_p( 1a – z ) and E_p ( 2a – z ) towards positive potentials. Linear correlations have been found between E_p( 1a – z ) (E_p( 2a – z )) of RCbl^III (R‘Cby’^III) and the pK_a of RH (or the Taft σ*- or the Hammett σ-values of R) within each class of R, i. e. MeCbl^III (Me‘Cby’^III), primary RCbl^III (R‘Cby’^III) and secondary RCbl^III (R‘Cby’^III). The correlations allow to distinguish between electronic effects of the Co-bound alkyl residues and their steric interactions with the corrin side chains. The correlations have further been used to visualize the light-induced formal insertion of an olefin into the Co, C-bond of an alkylcobalamin (Scheme 2, 1a → 1u ), a key step in the vitamin-B₁₂-catalized C, C-bond formation.     

Comparative Pharmacokinetics after Feeding Fancy Carp (Cyprinus carpio) with Diets Containing Carotenoids from Natural Sources [Tea (Camellia sinensis), Mulberry (Morus alba), and Cassava (Manihot esculenta) Leaf]

JPC – Journal of Planar Chromatography – Modern TLC - The carotenoid composition of tea, mulberry, and cassava leaf has been determined by TLC on silica gel 60 with 75:15:10 (v/v)...