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Several novel copper (II) complexes of reduced Schiff bases containing fluoride substituents were prepared and structurally characterized by single-crystal X-ray diffraction. The complexes exhibited diverse structures, with the central atom in distorted tetrahedral geometry. The biological effects of the products were evaluated, specifically their cytotoxicity, antimicrobial, and antiurease activities, as well as affinity for albumin (BSA) and DNA (ct-DNA). The complexes showed marked cytotoxic activities in the HepG2 hepatocellular carcinoma cell line, considerably higher than the standard cisplatin. The cytotoxicity depended significantly on the substitution pattern. The best activity was observed in the complex with a trifluoromethyl group in position 4 of the benzene ring—the dichloro[(±)-trans-N,N′-bis-(4-trifluoromethylbenzyl)-cyclohexane-1,2-diamine]copper (II) complex, whose activity (IC50 28.7 μM) was higher than that of the free ligand and markedly better than the activity of the standard cisplatin (IC50 336.8 μM). The same complex also showed the highest antimicrobial effect in vitro. The affinity of the complexes towards bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) was established as well, indicating only marginal differences between the complexes. In addition, all complexes were shown to be excellent inhibitors of the enzyme urease, with the IC50 values in the lower micromolar region. [ABSTRACT FROM AUTHOR]

Multi‐functional polymers used for personal care products can be synthesized by radical polymerization of acrylic acid (AA) in alcohol/water solutions with non‐functional monomers such as methyl acrylate (MA) and N‐tert‐butylacrylamide (t‐BuAAm). However, solvents capable of forming or disrupting hydrogen bonds cause the polymerization kinetics of these monomers to deviate from their polymerization behaviour in bulk and non‐polar solvents. In this work, a previous mechanistic model developed for MA/t‐BuAAm copolymerization is extended to represent the terpolymerization system MA/t‐BuAAm/AA. The additional kinetic coefficients required for the system are estimated from fitting to AA homopolymerizations and AA/MA and AA/t‐BuAAm copolymerizations conducted in an ethanol/water solution. In‐situ nuclear magnetic resonance (NMR) spectroscopy is used to follow monomer conversions and composition drift behaviour, with the molar mass distributions of the polymer products characterized by size‐exclusion chromatography. Although AA is more reactive than MA in non‐polar solvents, the reactivities of the two monomers equalize under the experimental conditions examined. Thus, the batch and semi‐batch terpolymerization data collected are represented equally well by a reduced acrylate/t‐BuAAm copolymerization model and the full terpolymerization implementation. [ABSTRACT FROM AUTHOR]

A series of Schiff base ligands obtained by the condensation of trans-cyclohexane-1,2-diamine and fluorinated benzaldehydes were prepared, followed by their reduction with NaBH4. The reduced ligands were employed in the synthesis of zinc complexes of the general formula [ZnCl2(L)]. The structures of both the original and the reduced Schiff bases, as well as of the zinc complexes, were characterized by single-crystal X-ray analysis, along with NMR and IR spectroscopy. The antimicrobial activities of the reduced Schiff bases and their zinc complexes were evaluated in vitro against E. coli, S. aureus, and C. albicans. The compounds containing the 4-(trifluoromethylphenyl) moiety showed marked antibacterial activity. Interestingly, the antimicrobial effect of the zinc complex with this moiety was significantly higher than that of the corresponding free reduced ligand, comparable with ciprofloxacin used as standard. Thus, a synergic effect upon the complexation with zinc can be inferred. [ABSTRACT FROM AUTHOR]

A series of phosphonium amphiphilic compounds was synthesized. Cationic parts of molecules contain triphenylphosphonium moieties. Lipophilic parts of compounds are represented by straight alkyl chain or the alkyl chains which are ornamented by benzyl or metronidazole. The physicochemical properties of phosphonium amphiphilic compounds were investigated by the measurements of surface tension and conductivity. The critical micelle concentration (cmc), the surface tension value at the cmc (γcmc), the surface area at the surface saturation per head group (Acmc) were determined. The lowest cmc value was determined for phosphonium salts with straight dodecyl alkyl chain. Its value was 1.5 × 10−3 mol dm−3. Surface tension at the cmc decreases with the addition of bulky moieties (benzyl, radical from metronidazol) at the end of alkyl chains. Biological activities of compounds were studied on human erythrocytes and strains of Acanthamoeba lugdunensis and Acanthamoeba quina. Dodecyltriphenylphosphonium bromide showed the highest activity against Acanthamoeba. To the best of our knowledge, it is the first compound of the group of phosphonium amphiphiles, which exhibited high activity against Acanthamoeba. The determined structure–activity relationship indicated nonspecific trophocidal and hemolytic activity that depends on physicochemical properties of the studied compounds. [ABSTRACT FROM AUTHOR]

Diastereoselective ortho-lithiation of ferrocenes is a principal strategy for the synthesis of chiral ferrocene ligands. Dilithiation of ( R)-1-(2-bromophenyl)-1-ferrocenyl- N, N-dimethylmethanamine leads to a dilithium intermediate, which can be transformed to a Taniaphos ligand with ( R, Rp)-configuration. On the other hand, lithiation of ( R)-1-phenyl-1-ferrocenyl- N, N-dimethylmethanamine affords a lithiated product with opposite configuration of the stereogenic plane. Presumably, the second lithium atom attached at the ortho-position of the phenyl ring is responsible for this difference through the intramolecular multicenter arrangement involving both lithium atoms and their adjacent carbon atoms, the iron atom of the ferrocenyl moiety, and the nitrogen atom of the amino group. This hypothesis has been supported also by quantum chemical calculations. [ABSTRACT FROM AUTHOR]

The diastereoselectivity of [3+2] cycloaddition of tricarbonyl[(4,5,6,7-η)-2-methyltropone]iron (2) with an E,Z isomeric mixture of η1-(crotyl)Fp (4E/4Z) [Fp: C5H5Fe(CO)2 or CpFe(CO)2] has been studied. By this cyclopentaanulation, four stereogenic centres are formed. The reaction occurs regioselectively and stereoselectively. The relative configurations of the cycloadducts 5a, 5b and 5c were assigned on the basis of 2D and NOE NMR experiments. A mechanism for the stereoselective [3+2] cycloaddition has been proposed. The selectivity of the cycloaddition depends on the difference in steric discrimination approaches of the η1-(crotyl)Fp 4E/4Z to the tricarbonyl[(3,4,5,6,7-η)-1-trimethylsilyloxy-2-methyltropylium]iron 3 (repulsion of the methyl and methylene groups of 4 and the planar skeleton of 3) and also upon the isomeric structure (E or Z) of the η1-(crotyl)Fp reactant. The geometrical isomerism of the reagent (4E/4Z) is preserved in the products 5a–c. [Copyright &y& Elsevier]

Abstract: In this study, we demonstrate the synthesis of the [Al13O4(OH)24(H2O)12]7+ Keggin ε-Al13 ion by a mechanochemical reaction between [Al(H2O)6]Cl3 and (NH4)2CO3 reactants. Five grams of the starting mixture corresponding to a molar ratio of (NH4)2CO3/[Al(H2O)6]Cl3 =0.45:2, 1:2, 1.5:2, 2:2, 2.25:2, 2.55:2 and 3:2 was milled for 5min. The existence of ε-Al13 was observed at molar ratios of (NH4)2CO3/[Al(H2O)6]Cl3 =2:2 and higher. Our results show that more than 50% mass of Al from a starting [Al(H2O)6]Cl3 was bonded to the polymeric [Al13O4(OH)24(H2O)12]7+ ionic form at a molar ratio of 2.55:2. [Copyright &y& Elsevier]

Cationic gemini surfactants with polymethylene spacer and linear alkyl chains containing an even number of carbon atoms have been extensively studied in the recent past, with the emphasis put on the determination of their aggregation behaviour in aqueous solution and their biological properties. However, the information on the aggregation of branched gemini surfactants with an odd number of carbon atoms in their alkyl chains is only sparsely reported in the literature. To help cover this gap in the research of cationic gemini surfactants, a series of branched bisammonium cationic gemini surfactants with an odd number of carbon atoms in alkyl chains (tridecane-2-yl chains) and a polymethylene spacer with a variable length ranging from 3 to 12 carbon atoms have been synthesized and investigated. Critical micelle concentration, which was determined by three methods, was found to be in the order 10−4 mol/L. A comparison of the obtained data of the novel series of tridecyl chain geminis with those of gemini surfactants with dodecyl chains and an identical spacer structure revealed that structural differences between both series of gemini surfactants result in different aggregation and surface properties for surfactants with 6 and 8 methylene groups in the spacer (N,N'-bis(tridecane-2-yl)-N,N,N',N'-tetramethylhexane-1,6-diaminium dibromide and N,N'-bis(tridecane-2-yl)-N,N,N',N'-tetramethyloctane-1,8-diaminium dibromide) with the cmc values 8.2 × 10−4 mol/L and 6.5 × 10−4 mol/L, respectively, as determined by surface tension measurements. Particle size analysis showed the formation of small stable spherical micelles in the interval between 2.8 and 5 nm and with zeta potential around +50 mV, which are independent of surfactant concentration and increase with the increasing spacer length. Microbicidal activity of 13-s-13 gemini surfactants was found to be efficient against Gram-positive, Gram-negative bacteria and yeast. [ABSTRACT FROM AUTHOR]

The basal production of secondary metabolites in medicinal plants is limited. One of the effective approaches that encourages plants to produce a remarkable amount of precious compounds is an application of elicitors. Our work was focused on the elicitation of Eschscholzia californica Cham. suspension cultures using various concentrations of MnCl2 (5; 10; 15 mg/L) with the aim of evaluating its effect on sanguinarine, chelerythrine, and macarpine production and gene expression of enzymes involved in the biosynthesis of mentioned secondary metabolites (BBE, 4′-OMT, CYP80B1) or in defense processes (LOX). Suspension cultures were exposed to elicitor for 24, 48, and 72 h. The content of alkaloids in phytomass was determined on the basis of their fluorescence properties. The relative mRNA expression of selected genes was analyzed using the ΔΔCt value method. PCR products were evaluated by melting curve analysis to confirm the specific amplification. Our results demonstrated that Eschscholzia californica Cham. cell suspension cultures evince sensitivity to the presence of MnCl2 in growth media resulting in the increased production of benzophenanthridine alkaloids and gene expression of selected enzymes. Manganese chloride seems to be a potential elicitor supporting natural biosynthetic properties in plant cell cultures and can be applied for the sustained production of valuable secondary metabolites. [ABSTRACT FROM AUTHOR]

Graphical abstract Glide docking model of 2,2′-((6-((4-sulfamoylphenethyl)amino)-1,3,5-triazine-2,4-diyl)bis(imino))disuccinic acid associate with carbonic anhydrase IX. Highlights • Novel sulfonamides incorporating 1,3,5-triazine and amino acid structural motifs. • Green synthesis of disubstituted amino acid products with high selectivity and yield. • Study on inhibition activity of products toward carbonic anhydrases I, II, IV, IX. • Found highly effective inhibitors toward tumor-associated hCA IX. • Docking study on the most promising enzyme-substrate complex. Abstract A new series of thirty s-triazinyl-substituted aminoalkylbenzenesulfonamides, incorporating a symmetric pair of amino acid moieties, is reported, together with inhibition studies of physiologically relevant human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms. Specifically, against the cytosolic hCA I, II, transmembrane hCA IV and the tumor-associated, membrane-bound hCA IX. The compounds were prepared by nucleophilic substitution of chlorine atoms from cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) using environmentally friendly water-based synthetic conditions. The products yields ranged in the interval of 43–97%. Purity of the products was verified by the HPLC-DAD-ESI-Q-TOF MS method. Identity of the products was confirmed by the same method plus NMR and IR. The products showed weak inhibition of the cytosolic, off-target isozyme hCA II, but some of them were low nanomolar (i.e. strong) inhibitors of the tumor-associated hCA IX. The series offered representatives selective towards isozymes hCA I, IV and IX. 2,2′-((6-((4-sulfamoylphenethyl)amino)-1,3,5-triazine-2,4-diyl)bis(imino))disuccinic acid demonstrated highest selectivity to the tumor-associated isoform hCA IX over off-target isozymes, with impressive K I ratio (hCA II/hCA IX) 213.9 and inhibition constant equal to acetazolamide (K I = 25.8 nM). Although the selectivities of some other products, e.g. those conjugating Leu and Glu, were a bit lower (188.7 and 84.3, respectively) their inhibition constants were similar to acetazolamide too (24.0 and 27.1, respectively). The selected most impressive results from the inhibition study were interpreted via molecular modeling experiment (docking in Glide) revealing different inter-molecular enzyme-substrate interaction of 2,2′-((6-((4-sulfamoylphenethyl)amino)-1,3,5-triazine-2,4-diyl)bis(imino))disuccinic acid within specific hCA IX and hCA II microregions. Therefore, several selected compounds from this study can be considered as highly effective and selective inhibitors of hCA IX, worthy to further (preclinical) investigation. [ABSTRACT FROM AUTHOR]

The (15)N as well as (13)C and (1)H chemical shifts of eight push-pull benzothiazolium iodides with various pi-conjugated chains between dimethylamino group and benzothiazolium moiety have been determined by NMR spectroscopy at the natural-abundance level of all nuclei in DMSO-d(6) solution. In general, the quaternary benzothiazolium nitrogen is more shielded [delta((15)N-3) vary between - 241.3 and - 201.9 ppm] with respect to parent 3-methylbenzothiazolium iodide [delta((15)N-3) = - 183.8 ppm], depending on the length and constitution of the pi-conjugated bridge. A larger variation in (15)N chemical shifts is observed on dimethylamino nitrogen, which covers the range of - 323.3 to - 257.2 ppm. The effect of pi-conjugation degree has a less pronounced influence on (13)C and (1)H chemical shifts. Experimental data are interpreted by means of density functional theory (DFT) calculations. Reasonable agreement between theoretical and experimental (15)N NMR chemical shifts was found, particularly when performing calculations with hybrid exchange-correlation functionals. A better accord with experiment is achieved by utilizing a polarizable continuum model (PCM) along with an explicit treatment of hydrogen-bonding between the solute and the water present in dimethylsulfoxide (DMSO). Finally, (13)C and (1)H NMR spectra were computed and analysed in order to compare them with available experimental data., ((c) 2007 John Wiley & Sons, Ltd.)