Aluminum,Arsenic, Beryllium,Cadmium, Chromium,Cobalt, Copper,Iron, Lead,Mercury, Molybdenum,Nickel, Platinum,Thallium, Titanium,Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl₂ causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.     

Loops, linkages, rings, catenanes, cages, and crowders: entropy-based strategies for stabilizing proteins

A protein molecule exists in either a compact folded state or a variable and open unfolded state. Since the unfolded state is favored by chain entropy, restricting its entropy is an attractive mechanism for shifting the equilibrium toward the folded state. A number of entropy-based strategies have been engineered or used by natural proteins to increase the folding stability: (a) shortening of loop lengths, (b) covalent linkage of dimeric proteins, (c) backbone cyclization, (d) catenation, (e) spatial confinement, and (f) macromolecular crowding. Theoretical analyses demonstrate the importance of accounting for consequences on the folded as well as the unfolded state and provide guidance for further exploitation of these stabilization strategies.     

A methacrylate monomer bearing nitro,aryl, and hydroxyl side groups: Homopolymerization,characterization, dielectric,and thermal degradation behaviors

2‐Hydroxy‐3‐(4‐nitrophenoxy)propyl methacrylate (HNPPMA) monomer was synthesized. The poly(HNPPMA) was prepared by free radical polymerization (FRP) method. The characterization of poly(HNPPMA) was carried out using FT‐IR, NMR, differential scanning calorimetry, and GPC techniques. The thermal stability and degradation behavior of this polymer have been studied by using thermogravimetry (TG), GC‐MS, NMR, and FT‐IR. The results were in comparison to poly[2‐hydroxy‐3‐(1‐naphtyloxy)propyl methacrylate] sample with α‐naphtyloxy side group prepared by the same method in the our previous study. The effect of thermal activation on non‐isothermal decomposition kinetics of poly(HNPPMA) was investigated using thermogravimetric analysis according to Flynn‐Wall‐Ozawa method. The dielectric measurements of poly(HNPPMA) and doped with europium(III)chloride (EuCI₃) were investigated by impedance analyzer technique in range of 10–4000 Hz frequency by depending on the alternating current conductivities. The mode of thermal degradation including formation of the main products of poly(HNPPMA) degraded from ambient temperature to 500 °C was identified. S°, the cold ring fraction (CRF) was collected from room temperature to 500 °C. The structure of the degradation products has also been studied depending on the GC‐MS analysis. The thermal degradation mechanism for poly(HNPPMA) with radical degradation processes thought to dominate at high temperature was proposed based on GC/MS, NMR, FT‐IR, and taking into account the new products and differences in stability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43925.     

Process synthesis of hybrid coal,biomass, and natural gas to liquids via Fischer–Tropsch synthesis,ZSM-5 catalytic conversion,methanol synthesis,methanol-to-gasoline,and methanol-to-olefins/distillate technologies

Several technologies for synthesis gas (syngas) refining are introduced into a thermochemical based superstructure that will convert biomass, coal, and natural gas to liquid transportation fuels using Fischer–Tropsch (FT) synthesis or methanol synthesis. The FT effluent can be (i) refined into gasoline, diesel, and kerosene or (ii) catalytically converted to gasoline and distillate over a ZSM-5 zeolite. Methanol can be converted using ZSM-5 (i) directly to gasoline or to (ii) distillate via olefin intermediates. A mixed-integer nonlinear optimization model that includes simultaneous heat, power, and water integration is solved to global optimality to determine the process topologies that will produce the liquid fuels at the lowest cost. Twenty-four case studies consisting of different (a) liquid fuel combinations, (b) refinery capacities, and (c) superstructure possibilities are analyzed to identify important process topological differences and their effect on the overall system cost, the process material/energy balances, and the well-to-wheel greenhouse gas emissions.     

Design,synthesis, structure,and stability of novel multi-principal element (Ti,Zr,Hf,W)C ceramic with a miscibility gap

Here we design a novel multi-principal element carbide system (Ti,Zr,Hf,W)C with a miscibility gap using computational tools and report on the formation of a single-phase (Ti,Zr,Hf,W)C after spark plasma sintering. The (Ti,Zr,Hf,W)C shows high nanohardness (32.7 GPa) and fracture toughness (5 MPa·m^1/2). Aging studies at 1350 °C for 100 h show that the single-phase carbide solid solution is quite stable even though this temperature is within the predicted miscibility gap of the system. Detailed electron microscopy characterization shows that phase separation has initiated with minor decomposition after aging by forming rock-salt (Ti,W)C- and (Zr,Hf)C-rich phases as well as hexagonal WC precipitates. We show that the (Ti,W)C- and (Zr,Hf)C-rich phases form a lamellar structure upon aging and the interlamellar spacing is considerably coarser than what has been previously found for the binary (Ti,Zr)C system. The decomposition kinetics, on the other hand, is sluggish due to the reduced driving force for phase decomposition.     

CHIPS, FISH SCALES, AND SHINERS, IV

The effusion of hydrogen from enameled steel to cause fractures in the enamel was investigated in an attempt to show that this gas may cause defects that range from plate-like fractures, or “chips,” through the known types of fish scales to the most minute shiner. The difference in the appearance of these defects was found to depend principally on differences in (1) the physical properties of the enamel, (2) the metal-enamel bond, and (3) the rate, quantity, and localization of the hydrogen effusion. Reboiling is shown to be related to fish scaling and to the other fracture-type defects because all are primarily hydrogen functions. The principal source of the critical quantities of hydrogen necessary to cause the defects is often found in the water of hydration in the dried slip, and the injection of hydrogen by that water during firing is demonstrated by experiment just as was shown for blister-type defects (see this issue, pp. 180-90). The prevention of fracture-type defects is discussed, and some novel effects of protective surface oxidation are illustrated.     

Self-crosslinked poly-L-ornithine and poly-L-arginine networks: Synthesis,characterization, pH-responsibility,biocompatibility, and AIE-functionality

A pH-responsive hydrogel consists of polypeptides only is a promising biomaterial with the advantages of good biocompatibility and non-toxicity. This work reports the synthesis of poly-L-ornithine(poc) (polyLOpoc) serving as the precursor for hydrogels of poly-L-ornithine (polyOrn) and poly(L-arginine-r-L-ornithine) (poly(Arg-r-Orn)). Their controllable degree of crosslinking, good mechanical properties, good biocompatibility, and pH-responsibility are detailedly investigated. The swelling ratio of polyOrn hydrogel in acidic aqueous solution is 5.7 times higher than that in a basic environment. In the deprotection of phenoxycarbonyl group, polyLOpoc releases amino pendant groups, which attack the remaining poc-protected amino groups to fulfill self-crosslinking without any crosslinking agent. In addition, the pH-responsive behavior of hydrogels is visualized by aggregation-induced emission phenomena with polyOrn and poly(Arg-r-Orn) containing tetrakis(4-aminophenyl)ethene moisture.     

Selective cyclisation of 2, 3, 4, 5-tetra-O-acetyl-galactaric acid bis-[Alkylthio(thiocarbonyl)]hydrazide to Saccharide 1, 3, 4-Oxadiazole,Thiadiazole, and thiadiazoline derivatives

The synthesis of galactaric acid acetate bis[alkylthio(thiocarbonyl)]hydrazide ( 1 , 2 ) is described. Selective cyclisation of both hydrazides 1 and 2 was investigated. Phosphorous oxychloride as cyclising agent led to dehydrative cyclisation and produced 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or — benzyl) 1, 3, 4-thiadiazol-2-yl galactotetritol ( 3 ) or ( 4 ). While thionyl chloride led to dehydrosulfurization and gave 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or -benzyl)-1, 3, 4-oxadiazol-2-yl galactotetritol ( 5 ) or ( 6 ). Finally with triethyl orthoformate as cyclising agent, compounds 1 or 2 , gave 3, 3′-(2, 3, 4, 5-tetra-O-acetyl-galactar-1.6 dioyl)bis[2-ethoxy-2, 3-dihydro-5-S-methyl or benzyl 1, 3, 4-thiadiazole] ( 7 ) or ( 8 ).     

Synthetic,spectroscopic, magnetic,thermal, and antimicrobial approach towards new biocidal coordination polymers

O‐aminophenol was reacted with glutraldehyde to obtain Schiff base, which was then reacted with formaldehyde in slight acidic medium to generate phenolic groups. Now the substituted Schiff base was reacted with the transition metal acetates of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) to get polymeric metal complexes. Their structures have been elucidated on the basis of elemental analyses, ¹H NMR spectra, ¹³C NMR spectra, magnetic measurements, thermogravimetric analyses, electronic spectra, and infrared spectra. The results are in accordance with an octahedral environment around the central metal ion. The polychelates of Mn(II), Co(II), Ni(II), and Cu(II) are paramagnetic while Zn(II) polychelate was found to be diamagnetic. The synthesized Schiff base acted as a uninegative bidentate ligand and bonding occurs through the hydroxyl oxygen and nitrogen atoms. The thermal behavior of these coordinating polymers was studied by TGA in nitrogen atmosphere up to the temperature range of 800°C. All the synthesized polychelates were also screened for their biocidal activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis (bacteria), Candida albicans, and Muller species (yeast) by using agar well diffusion method. All the metal polychelates show promising antimicrobial activities. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124:3971–3979, 2012     

(Ti,Mo,W,Ta,V,Nb)(C,N)多元陶瓷相的价电子结构

运用固体与分子经验电子理论(EET理论)计算了(Ti,Mo,W,Ta,V,Nb)(C,N)多元陶瓷相的价电子结构.结果表明,价电子结构参数(nA)随碳化物添加量的增加而增加.不同碳化物对价电子结构参数的影响不同,其中VC的影响最为显著.价电子结构参数(nA)可以用来评价金属陶瓷的力学性能,提出了相关的判据关系式.     

Antiferroelectrics: History,fundamentals, crystal chemistry,crystal structures,size effects,and applications

Antiferroelectric (AFE) materials are of great interest owing to their scientific richness and their utility in high-energy density capacitors. Here, the history of AFEs is reviewed, and the characteristics of antiferroelectricity and the phase transition of an AFE material are described. AFEs are energetically close to ferroelectric (FE) phases, and thus both the electric field strength and applied stress (pressure) influence the nature of the transition. With the comparable energetics between the AFE and FE phases, there can be a competition and frustration of these phases, and either incommensurate and/or a glassy (relaxor) structures may be observed. The phase transition in AFEs can also be influenced by the crystal/grain size, particularly at nanometric dimensions, and may be tuned through the formation of solid solutions. There have been extensive studies on the perovskite family of AFE materials, but many other crystal structures host AFE behavior, such as CuBiP₂Se₆. AFE applications include DC-link capacitors for power electronics, defibrillator capacitors, pulse power devices, and electromechanical actuators. The paper concludes with a perspective on the future needs and opportunities with respect to discovery, science, and applications of AFE.     

Novel 1,3,5-Triazinyl Aminobenzenesulfonamides Incorporating Aminoalcohol,Aminochalcone and Aminostilbene Structural Motifs as Potent Anti-VRE Agents,and Carbonic Anhydrases I,II, VII,IX, and XII Inhibitors

A series of 1,3,5-triazinyl aminobenzenesulfonamides substituted by aminoalcohol, aminostilbene, and aminochalcone structural motifs was synthesized as potential human carbonic anhydrase (hCA) inhibitors. The compounds were evaluated on their inhibition of tumor-associated hCA IX and hCA XII, hCA VII isoenzyme present in the brain, and physiologically important hCA I and hCA II. While the test compounds had only a negligible effect on physiologically important isoenzymes, many of the studied compounds significantly affected the hCA IX isoenzyme. Several compounds showed activity against hCA XII; (E)-4-{2-[(4-[(2,3-dihydroxypropyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (31) and (E)-4-{2-[(4-[(4-hydroxyphenyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (32) were the most effective inhibitors with K_Is = 4.4 and 5.9 nM, respectively. In addition, the compounds were tested against vancomycin-resistant Enterococcus faecalis (VRE) isolates. (E)-4-[2-({4-[(4-cinnamoylphenyl)amino]-6-[(4-hydroxyphenyl)amino]-1,3,5-triazin-2-yl}amino)ethyl]benzenesulfonamide (21) (MIC = 26.33 µM) and derivative 32 (MIC range 13.80–55.20 µM) demonstrated the highest activity against all tested strains. The most active compounds were evaluated for their cytotoxicity against the Human Colorectal Tumor Cell Line (HCT116 p53 +/+). Only 4,4’-[(6-chloro-1,3,5-triazin-2,4-diyl)bis(iminomethylene)]dibenzenesulfonamide (7) and compound 32 demonstrated an IC₅₀ of ca. 6.5 μM; otherwise, the other selected derivatives did not show toxicity at concentrations up to 50 µM. The molecular modeling and docking of active compounds into various hCA isoenzymes, including bacterial carbonic anhydrase, specifically α-CA present in VRE, was performed to try to outline a possible mechanism of selective anti-VRE activity.     

Preparations,optical, structural,conductive and magnetic evaluations of RE's (Pr,Y, Gd,Ho, Yb) doped spinel nanoferrites

Rare earths RE's (Pr, Y, Gd, Ho, Yb) substituted MnZn spinel ferrites with composition of Mn_0.5Zn_0.5M_0.02Fe_1.98O₄ (M = Pr, Y, Gd, Ho, Yb) are prepared by sol gel combustion approach. Low sintering temperature (500 °C) is used to sinter the RE's doped MnZn samples. MnZn samples are further characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to measure the cubic crystalline structure, particle size, morphology, porosity and grain size. Cubic crystalline phase of prepared RE's doped MnZn ferrites is confirmed by x-ray diffraction (XRD). The morphology, porosity and grain size are observed using FESEM. The magnetic properties of RE's doped MnZn nanoferrites are analyzed by vibrating sample magnetometer (VSM). Coercivity (H_c), remanence (M_r) and saturation magnetization (M_s) are calculated from the magnetic loops. The saturation and remanence of the nanoferrites are increased by the substitution of RE's metal ions and varies from 14.76 to 26.36 emu/g and 9.98–22.48 emu/g respectively. Bohr magneton and anisotropy constant are calculated from the recorded magnetic data. The conductive analysis of the prepared samples is studied at 40 °C −300 °C temperature, leading to the conductivity measurements from 1.12 × 10^-2 Ω^-1-cm^-1 to 9.52 × 10^-2 Ω^-1-cm^-1. UV–Vis spectroscopy is used to determine the semi conducting nature of RE's doped MnZn spinel ferrite samples. The magnetic, conductive and optical study of the RE's doped MnZn nanoferrites sintered at low temperature suggests the use of these materials for microwave absorption, supercapacitor, lithium ion batteries and nanoelectronics industrial applications.     

Adsorption of dimer,trimer, stearic,oleic, linoleic,nonanoic and azelaic acids on ferric oxide

The adsorption isotherms of solutions of dimer, trimer, stearic, oleic, linoleic, nonanoic and azelaic acids in organic solvents, (mostly hexane) have been determined on an alpha ferric oxide with a surface area (B.E.T. N₂ adsorption) of 99 m² (99 × 10²⁰ A²) per gram. They all showed limiting adsorption as grams adsorbed per gram of iron oxide beyond a concentration of about 1 g/100 cc, analagous to the Langmuir type monolayer isotherm. Areas per molecule were calculated and compared with areas of close-packed models in positions parallel to and perpendicular to the surface. The calculated areas corresponded more closely to the flat or parallel positions. Heats of adsorption were determined and were in the range of 27–71 kcal/eq, suggesting chemisorption of the COOH group at the surface. The value of dimer acid suggests that both COOH groups are chemisorbed. Models show that the parallel position permits both COOH groups to touch the surface. The perpendicular position generally does not permit both COOH groups to touch the surface. Dimer acid showed a value (71 kcal/eq) higher than the monobasic acids (44–55 kcal/eq), possibly due to interaction of the ring structure (partly aromatic) with the surface. Azelaic acid from an 80–20t-butanol-hexane solvent showed a lower value of 27 kcal/eq, possibly due to adsorption of a hydrogenbonded alcohol-acid moiety as such. Journal Series No. 547, General Mills, Inc. Research Laboratories.     

Acetylcholinesterase Reactivators (HI-6, Obidoxime,Trimedoxime, K027, K075, K127, K203, K282): Structural Evaluation of Human Serum Albumin Binding and Absorption Kinetics

Acetylcholinesterase (AChE) reactivators (oximes) are compounds predominantly targeting the active site of the enzyme. Toxic effects of organophosphates nerve agents (OPNAs) are primarily related to their covalent binding to AChE and butyrylcholinesterase (BChE), critical detoxification enzymes in the blood and in the central nervous system (CNS). After exposure to OPNAs, accumulation of acetylcholine (ACh) overstimulates receptors and blocks neuromuscular junction transmission resulting in CNS toxicity. Current efforts at treatments for OPNA exposure are focused on non-quaternary reactivators, monoisonitrosoacetone oximes (MINA), and diacylmonoxime reactivators (DAM). However, so far only quaternary oximes have been approved for use in cases of OPNA intoxication. Five acetylcholinesterase reactivator candidates (K027, K075, K127, K203, K282) are presented here, together with pharmacokinetic data (plasma concentration, human serum albumin binding potency). Pharmacokinetic curves based on intramuscular application of the tested compounds are given, with binding information and an evaluation of structural relationships. Human Serum Albumin (HSA) binding studies have not yet been performed on any acetylcholinesterase reactivators, and correlations between structure, concentration curves and binding are vital for further development. HSA bindings of the tested compounds were 1% (HI-6), 7% (obidoxime), 6% (trimedoxime), and 5%, 10%, 4%, 15%, and 12% for K027, K075, K127, K203, and K282, respectively.     

Performance of a novel,eco-friendly,cellulose-based superabsorbent polymer (Cellulo-SAP): Absorbency,stability, reusability,and biodegradability

Superabsorbent polymers (SAPs) have attracted tremendous attention recently, with researchers noting that their high water absorbability is valuable for various applications, especially in agricultural contexts. Two types of materials can be used to produce SAPs: Fossil-based (which are harmful to the environment) and bio-based (which are significantly more environmentally friendly, given their biodegradability and minimal toxic side effects). Although bio-based SAPs are preferable for environmental reasons, their synthesis tends to be time consuming and labour intensive, while their absorption capacity (AC) can be far below expectations. To address these problems, a novel, eco-friendly, cellulose-based superabsorbent polymer (Cellulo-SAP) was developed in this study through facile preparation via free radical synthesis using modified cellulose. Then, the absorbency, thermal/pH stability, reusability, and biodegradability of Cellulo-SAP were evaluated. This new polymer demonstrated reusability as a water reservoir, in addition to high thermal and pH stability. More importantly, Cellulo-SAP achieved an AC of 475 g/g and exhibited superior biodegradability compared to a commercial, fossil-based SAP. Accordingly, these results prove that Cellulo-SAP can be used in agriculture as an effective alternative to fossil-based SAPs.     

Heme-copper/dioxygen adduct formation, properties, and reactivity

This Account focuses on our recent developments in synthetic heme/copper/O 2 chemistry, potentially relevant to the mechanism of action of heme-copper oxidases (e.g., cytochrome c oxidase) and to dioxygen activation chemistry. Methods for the generation of O 2 adducts, which are high-spin heme(Fe (III))-peroxo-Cu (II) complexes, are described, along with a detailed structural/electronic characterization of one example. The coordination mode of the O 2-derived heme-Cu bridging group depends upon the copper-ligand environment, resulting in micro-(O 2 (2-)) side-on to Fe (III) and end-on to Cu (II) (micro-eta (2):eta (1)) binding for cases having N 4 tetradentate ligands but side-on/side-on (micro-eta (2):eta (2)) micro-peroxo coordination with tridentate copper chelates. The dynamics of the generation of Fe (III)-(O 2 (2-))-Cu (II) complexes are known in some cases, including the initial formation of a short-lived superoxo (heme)Fe (III)(O 2 -) intermediate. Complexes with cross-linked imidazole-phenol "cofactors" adjacent to the copper centers have also been described. Essential investigations of heme-copper-mediated reductive O-O bond cleavage chemistry are ongoing.     

Cover Image,Volume 138, Issue 9

Blends of polypropylene (PP), polyamide 6 (PA6), and biodegradable polymers (BPs) such as poly(D,L-lactic acid) (PDLLA), poly(lactic acid-co-ε-caprolactone) (poly[LA-co-ε-CL]) and poly(ε-caprolactone) (PCL) were prepared using a twin-screw mini-extruder. The composition of the blend PP/PA6 was fixed at a mass proportion of 70/30, and the compatibilized blends contain 5 wt% of each BP. The morphology observed through scanning electronic microscopy, the dynamic mechanical thermal properties (DMTA), and the biodegradation test after composting and performing optical microscopy (OM) of the blends were investigated. The blend PP/PA6 compatibilized with polypropylene grafted with maleic anhydride (PPMA) was also obtained and used as a reference. The results showed that the PP/PA6/PPMA revealed a more homogeneous morphology and resulted in higher modulus; nevertheless, the sample obtained with the lower molar mass PDLLA as an alternative for PPMA showed a storage modulus behavior close to the reference material. Poly(LA-co-ε-CL) and PCL also showed changes in the morphology of the PA6 dispersed phase. Positive results were observed in the biodegradation test examined by OM for all samples containing BPs. The novelty of this work was to employ BPs as compatibilizing agents of the blends comprising PP/PA6, producing ternary blends with superior mechanical properties due to the better dispersion of the phases.     

Conjugated polymers with anionic dyes: Synthesis,properties, and sensing ability for nucleosides,DNA, and BSA

The reaction of N-(2,4-dinitrophenyl)pyridinium chloride (salt[Cl⁻]) with sodium salts of anionic dyes, such as acid red 52 (AR52), acid violet 49 (AV49), and coomassie brilliant blue G-250 (CBBG250) involves an anion exchange between the chloride anion of salt(Cl⁻) and sulfonium anion of the dyes, resulting in the generation of novel Zincke salts, namely, salt(AR52), salt(AV49), and salt(CBBG250), respectively. Reactions of salt(AR52), salt(AV49), and salt(CBBG250) with piperazine in the absence of catalysts resulted in the opening of the pyridinium ring to yield ionic polymers comprising units of 5-piperazinium-2,4-dienylideneammonium and the corresponding dye anion, namely polymer(AR52), polymer(AV49), and polymer(SBBG250), respectively. The corresponding model compounds for the polymers were also synthesized by reacting salt(AR52), salt(AV49), and salt(CBBG250) with piperidine. Polymer(AV49) and polymer(SBBG250) were found to be suitable for the detection of nucleosides, DNA, and proteins, realized by monitoring the changes in their UV–vis absorption spectra, arising from the anionic dyes within the polymers. The polymers and the model compounds were electrochemically oxidized in solution.