Low Molecular Weight Amines Research Articles

Dually Charged Acid Stable Tight Polyamine Composite Nanofiltration Membranes with Low Molecular Weight Amine Molecules for MgCl2 Rejection

Dually Charged Acid Stable Tight Polyamine Composite Nanofiltration Membranes with Low Molecular Weight Amine Molecules for MgCl₂ Rejection

Production of polyesteramides based on recycled PET and low molecular weight amine

A method for the obtaining of polyesteramides based on recycled polyethylene terephthalate (PET) is presented. The process of aminolysis is studied by FTIR spectroscopy. The eff ect of increasing the duration of the aminolysis process and the amount of PET on the complex of technological properties of polyesteramides is shown. According to the test results, the developed polyesteramides can be used as hardeners for epoxy oligomers.

К вопросу использования аминоспиртов в технологии производства строительных материалов

This article presents the results of a study of the possibility of using additives based on low molecular weight amines (isopropanolamines, diethanolisopropanolamine, triisopropanolamine) in building materials technology. The aim of the study is to find the optimal field of application of additives based on amino alcohols. The results of the study of additives on the properties of building mixtures based on Portland cement are presented. The range of studied dosages is 0,025-1 % of cement weight. The influence on the mobility of mortars, as well as on the compressive strength at the age of 7, 28, 56 days, was studied. The work was carried out both on mobile and rigid mixtures. The result of the work is an analysis of the effectiveness of the use of additives as plasticizers.

ДОСЛІДЖЕННЯ КОМПЛЕКСОУТВОРЕННЯ ПОЛІЕТИЛЕНІМІНУ З ЙОНАМИ МІДІ (ІІ), НІКЕЛЮ (ІІ), КОБАЛЬТУ (ІІ)

There is described the influence of polyethylenimine globule structure on complexation with copper (II), nickel (II) and cobalt (II) ions. There are determined the values of the coordination number with the change of the pH of the solution for the complexes of ethylenediamine, diethylenetriamine and polyethylenimine with metal ions. It is investigated that the complexation of these metal ions with low molecular weight amines passes through three stages and with PEI through two stages. It is shown that the content of free nitrogen atoms in PEI, which do not react with metal ions, increases with increasing concentration of PEI in solution. The number of monomer units associated with metal ions depends on the size of the globule of the macromolecule, as well as the reaction process. The complexation reaction in solution is determined by the diffusion of metal ions into the polymer globule. If the reaction takes place in a diffusion field at a low polymer concentration, the rate of complexation is proportional to the concentration of macromolecules and the concentration of metal ions in solution.

New Dye/Dendrimer Photoinitiating Systems Operating under Visible Radiation: Eco‐Friendly Synthesis of Highly Viscous Polymers

AbstractA series of new eco‐friendly photoinitiating systems (PIs) based on several water‐soluble xanthenic dye/PAMAM dendrimer formulations are tested by polymerizing a typical vinyl monomer such as acrylamide. After irradiation with visible LEDs, solutions of viscosity up to 15‐fold higher than those with PIs based on low molecular weight amines are obtained. A correlation between solution viscosity and dendrimer structure is also observed. Polymers with ultra‐high molecular weights up to around 107 are estimated from viscosimetric assays. In addition, very fast reactions are observed under direct solar radiation and the properties of the thus obtained polymers are similar to those synthesized with LEDs. The present findings are promissory for future research and technological applications of the PIs evaluated.

Sesquiterpene Lactones from Vernonia tufnelliae: Structural Characterization and Biological Evaluation.

The genus Vernonia is an extremely rich source of biologically active sesquiterpene lactones. The present report describes the spectroscopic structure elucidation and the cytotoxic and antimicrobial properties of five hitherto unknown germacranolide-like sesquiterpenoids and several known compounds. These new derivatives include a compound (1) with an unprecedented 10/5/5/6 tetracyclic framework featuring a hexahydro-1H,3H,7H-furo[3',4':3,4]furo[3,2-c]pyridin-1-one core resulting from an intramolecular cyclization cascade involving a methacrylate substituent and a low molecular weight amine. Furthermore, an elemane-germacranolide hybrid (2) and three amino acid-derived lactones (3-5) were characterized. A plausible biosynthetic pathway to the key alkaloid is presented, while shielding tensor calculations using DFT in combination with the DP4+ method were applied to elucidate its stereostructure. The newly characterized compounds along with ten known sesquiterpene lactones and phenolic compounds have been isolated from Vernonia tufnelliae, a medicinal plant from the western region of Cameroon. Their structures were consistent with spectroscopic and spectrometric data recorded. The present report is the first investigation of the chemistry and biology of V. tufnelliae.

Role of Polyamines and Hypusine in β Cells and Diabetes Pathogenesis.

The polyamines—putrescine, spermidine, and spermine—are polycationic, low molecular weight amines with cellular functions primarily related to mRNA translation and cell proliferation. Polyamines partly exert their effects via the hypusine pathway, wherein the polyamine spermidine provides the aminobutyl moiety to allow posttranslational modification of the translation factor eIF5A with the rare amino acid hypusine (hydroxy putrescine lysine). The “hypusinated” eIF5A (eIF5Ahyp) is considered to be the active form of the translation factor necessary for the translation of mRNAs associated with stress and inflammation. Recently, it has been demonstrated that activity of the polyamines-hypusine circuit in insulin-producing islet β cells contributes to diabetes pathogenesis under conditions of inflammation. Elevated levels of polyamines are reported in both exocrine and endocrine cells of the pancreas, which may contribute to endoplasmic reticulum stress, oxidative stress, inflammatory response, and autophagy. In this review, we have summarized the existing research on polyamine-hypusine metabolism in the context of β-cell function and diabetes pathogenesis.

Current status and perspectives on the role of polyamines in plant immunity

AbstractPolyamines are low molecular weight amines, with versatile and essential functions during the lifespan of prokaryotes and eukaryotes. Modulation of polyamine metabolism under biotic stress has attracted a great deal of interest; however, the precise functions of these amines in plant defence responses to pathogen attack are still poorly understood. Herein we summarise and review important aspects of the regulation of polyamine biosynthesis, catabolism and conjugation under biotic stress that might contribute to improve present‐day knowledge about these compounds in plant immunity. Particular attention is paid to the intracellular localisation of the proteins/enzymes associated to polyamine metabolism, as well as the impact of pathogen effector proteins on the control of plant polyamine metabolism is discussed.

Computational study on atmospheric transformationmechanisms and kinetics of volatile amines

<p indent="0mm">Ambient atmosphere contains large amounts of volatile organic compounds (VOCs). They have both anthropogenic and biogenic sources. In general, natural sources dominate over anthropogenic sources on a global scale. However, anthropogenic emissions play an important role in urbanized areas. VOCs released into the atmosphere can undergo various atmospheric transformation. Previous studies indicated that the atmospheric transformation of VOCs can contribute to the formation of O₃ and secondary organic aerosol (SOA), which can influence the regional air quality and the global climate. Therefore, detailed atmospheric transformation mechanisms and kinetics of VOCs are indispensable to quantify the regional or global impacts of VOCs chemistry. Amines are an important kind of VOCs, and are emitted from a variety of natural and anthropogenic sources including animal husbandry, biomass burning, motor vehicles, cooking, fish processing, sewage treatment, waste incineration, vegetation, soil and ocean, etc. In addition, CO₂ capture unit in a promising amines-based post-combustion CO₂ capture (PCCC) technology has become an important source of anthropogenic amines in the atmosphere. Besides, it has been found that amines solvents can be degraded in the capture units, and the solvents degradation can take as much as 10% of total cost of CO₂ capture. The degradation products of amines in the capture units include some low molecular weight amines (such as methylamine, dimethylamine, trimethylamine), ammonia, amides, nitrosamines, aldehydes, and other species. Therefore, with the large-scale application of amines-based PCCC technology, the types and concentrations of amines in the atmosphere will be increased. In recent years, more and more attentions have been paid to the atmospheric transformation mechanisms and kinetics of amines emitted from PCCC units. Based on the previous review of the atmospheric transformation of amines, this review summarized the latest results from computational studies on the atmospheric transformation mechanisms and kinetics of amines emitted from PCCC units published after the year 2012. The two kinds of atmospheric transformation pathways (oxidation reactions and participation in the new particle formation) of CO₂ capture related amines were summarized in this review. Finally, an outlook for atmospheric transformation of amines was proposed. This could be helpful to understand the fate of amines from PCCC units and its impacts on human health and the environment.

Simultaneous determination of nine atmospheric amines and six inorganic ions by non-suppressed ion chromatography using acetonitrile and 18-crown-6 as eluent additive

Atmospheric amines contribute to the nucleation and initial growth of new particles as well as secondary organic aerosol formation, influencing the radiative balance of the Earth's atmosphere. In this study, we develop an ion chromatography (IC) method for separating and quantifying the nine most abundant amines (methylaminium (MMAH+), dimethylaminium (DMAH+), trimethylaminium (TMAH+), ethylaminium (MEAH+), diethylaminium (DEAH+), propylaminium (MPAH+), butylaminium (MBAH+), ethanolaminium (MEOH+), and triethanolaminium (TEOH+)) from six common inorganic species in atmospheric aerosols. The retention times of the amines were altered by the addition of acetonitrile to the eluent because acetonitrile can reduce the adsorption of hydrophobic amines on the stationary phase. The developed method achieved the successful separation of DEAH+ and TMAH+ from inorganic cations, which often coelute with each other in established IC methods. The interference of K+ on the determination of MEAH+ was eliminated by the complexation of K+ with 18-crown-6, which prolonged the retention time of K+. Finally, 9 target amines and 6 common inorganic cations were separated, with a resolution Rs ≥ 1.2 for DEAH+ and MPAH+ and Rs > 1.5 for other species. The detection limits varied in the range of 0.34-1.48 ng for the 9 amines and 0.19-0.56 ng for the inorganic cations. The developed method was successfully applied for the determination of low molecular weight amines and inorganic cations in PM2.5 collected from an urban site in Shanghai and an isolated coast of Chongming Island. Eight amines were detected in the urban samples, in which MMAH+ and DMAH+ dominated. The average amine concentration in the urban aerosols was 76.3 ± 38.4 ng m−3, which is approximately 4-fold higher than those in the marine samples collected from the coast.

Impedimetric Detection of Ammonia and Low Molecular Weight Amines in the Gas Phase with Covalent Organic Frameworks.

Two Covalent Organic Frameworks (COF), named TFP-BZ and TFP-DMBZ, were synthesized using the imine condensation between 1,3,5-triformylphloroglucinol (TFP) with benzidine (BZ) or 3,3-dimethylbenzidine (DMBZ). These materials were deposited, such as films over interdigitated electrodes (IDE), by chemical bath deposition, giving rise to TFP-BZ-IDE and TFP-DMBZ-IDE systems. The synthesized COFs powders were characterized by Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared spectroscopy (FT-IR), solid-state Nuclear Magnetic Resonance (ssNMR), nitrogen adsorption isotherms, Scanning Electron Microscopy (SEM), and Raman spectroscopy, while the films were characterized by SEM and Raman. Ammonia and low molecular weight amine sensing were developed with the COF film systems using the impedance electrochemical spectroscopy (EIS). Results showed that the systems TFP-BZ-IDE and TFP-DMBZ-IDE detect low molecular weight amines selectively by impedimetric analysis. Remarkably, with no significant interference by other atmospheric gas compounds such as nitrogen, carbon dioxide, and methane. Additionally, both COF films presented a range of sensitivity at low amine concentrations below two ppm at room temperature.

Profiling of amino acids and their interactions with proteinaceous compounds for sewage sludge dewatering by Fenton oxidation treatment

During advanced oxidation treatment for enhancing sludge dewaterability, the peptide chains of protein can be decomposed into amino acids. Protein exhibits a great impact on sewage sludge dewaterability. However, the role of amino acids in sludge dewatering remains unclear. In this study, among the 23 types of amino acids investigated, tryptophane (Trp) and lysine (Lys) were identified as the key amino acids affecting sludge dewaterability during Fenton oxidation treatment. The content of lysine showed positive correlations with capillary suction time (CST), specific resistance to filtration (SRF), and bound water content, and the concentrations of total protein, low molecular weight protein, amines and amides, and 3-turn helix of proteinaceous compounds in bound extracellular polymeric substances (EPS), while the content of tryptophane showed negative correlations with the above parameters. The amino acids may be sourced from damage of the membrane and ribosomal proteins by hydroxyl radicals, and the peptide bonds connected with tryptophane were more inclined to be decomposed than other amino acids. Particularly, more amino acids of tryptophane can result in more hydrophobic interaction, and less necessary energy barrier for aggregation of particles. As such, regulating protein degradation towards production of tryptophane may be related with enhanced sludge dewaterability by Fenton oxidation treatment.

Reaction-Based Amine and Alcohol Gases Detection with Triazine Ionic Liquid Materials.

We demonstrated in this work the use of affinity ionic liquids, AIL 1 and AIL 2, for chemoselective detection of amine and alcohol gases on a quartz crystal microbalance (QCM). These detections of gaseous amines and alcohols were achieved by nucleophilic aromatic substitution reactions with the electrophilic 1,3,5-triazine-based AIL 1 thin-coated on quartz chips. Starting with inexpensive reagents, bicyclic imidazolium ionic liquids AIL 1 and AIL 2 were readily synthesized in six and four synthetic steps with high isolated yields: 51% and 63%, respectively. The QCM platform developed in this work is readily applicable and highly sensitive to low molecular weight amine gases: for isobutylamine gas (a bacterial volatile) at 10 Hz decrease in resonance frequency (i.e., ΔF = −10 Hz), the detectability using AIL 1 was 6.3 ppb. Our preliminary investigation on detection of the much less nucleophilic alcohol gas by AIL 1 was also promising. To our knowledge, no example to date of reports based on nucleophilic aromatic substitution reactions demonstrating sensitive gas detection in these triazine ionic liquids on a QCM has been reported.

Photocatalytic degradation of β-blockers in TiO2 with metoprolol as model compound. Intermediates and total reaction mechanism

The photocatalytic degradation of β-blockers in TiO2 was investigated. Metoprolol (MET) was selected as a model compound since its structure is quite similar to several compounds utilized as β-blockers. MET degradation as a function of time was investigated by means of several analytical techniques. Analyzing the degradation mixtures by total organic carbon (TOC) analyzer and high-performance liquid chromatography (HPLC), it was evident that after one hour of irradiation, MET was transformed into other more recalcitrant intermediates. Latter intermediates were slowly degraded achieving 80% mineralization after four hours of irradiation. Gas chromatography – mass spectrometry (GC–MS) analysis of mixtures obtained upon irradiation at short reaction times (an hour or less) allowed the identification of several new intermediate organic compounds. Among those, several aromatic and low molecular weight amines. Polyhydroxylated compounds were also identified but only in trace amounts. Infrared (IR) and ultraviolet-visible (UV–vis) spectroscopy studies indicated that MET is first transformed into several hydroxylated aromatic compounds. Eventually, after several hours of irradiation, these compounds are transformed into low molecular weight unsaturated acids. HPLC analysis of reaction mixtures and coinjection of standard solutions allowed the detection of several intermediates, namely 1,4-hydroquinone, 4-(2-methoxyethyl)phenol, 2-(4-hydroxyphenyl)ethanol, 4-hydroxybenzandehyde, 1,2,4-benzenetriol, catechol and oxalic acid. Nuclear magnetic resonance (NMR) studies in deuterated solvents allowed the unequivocal detection of some of the aromatics in the reaction mixture. These NMR studies also demonstrated the transformation of aromatics into low molecular alkenes and acids. MET degradation routes and a detailed reaction mechanism is presented based on the intermediates identified. Fundamental aspects about MET degradation will be quite useful for future applications of photocatalysis in the degradation of other β-blockers, pharmaceuticals and organic compounds with structures similar to MET.

Myeloperoxidase-catalyzed oxidation of cyanide to cyanate: A potential carbamylation route involved in the formation of atherosclerotic plaques?

Protein carbamylation by cyanate is a post-translational modification associated with several (patho)physiological conditions, including cardiovascular disorders. However, the biochemical pathways leading to protein carbamylation are incompletely characterized. This work demonstrates that the heme protein myeloperoxidase (MPO), which is secreted at high concentrations at inflammatory sites from stimulated neutrophils and monocytes, is able to catalyze the two-electron oxidation of cyanide to cyanate and promote the carbamylation of taurine, lysine, and low-density lipoproteins. We probed the role of cyanide as both electron donor and low-spin ligand by pre-steady-state and steady-state kinetic analyses and analyzed reaction products by MS. Moreover, we present two further pathways of carbamylation that involve reaction products of MPO, namely oxidation of cyanide by hypochlorous acid and reaction of thiocyanate with chloramines. Finally, using an in vivo approach with mice on a high-fat diet and carrying the human MPO gene, we found that during chronic exposure to cyanide, mimicking exposure to pollution and smoking, MPO promotes protein-bound accumulation of carbamyllysine (homocitrulline) in atheroma plaque, demonstrating a link between cyanide exposure and atheroma. In summary, our findings indicate that cyanide is a substrate for MPO and suggest an additional pathway for in vivo cyanate formation and protein carbamylation that involves MPO either directly or via its reaction products hypochlorous acid or chloramines. They also suggest that chronic cyanide exposure could promote the accumulation of carbamylated proteins in atherosclerotic plaques.

Transglutaminase 2: Friend or foe? The discordant role in neurons and astrocytes.

Members of the transglutaminase family catalyze the formation of isopeptide bonds between a polypeptide-bound glutamine and a low molecular weight amine (e.g., spermidine) or the ɛ-amino group of a polypeptide-bound lysine. Transglutaminase 2 (TG2), a prominent member of this family, is unique because in addition to being a transamidating enzyme, it exhibits numerous other activities. As a result, TG2 plays a role in many physiological processes, and its function is highly cell type specific and relies upon a number of factors, including conformation, cellular compartment location, and local concentrations of Ca2+ and guanine nucleotides. TG2 is the most abundant transglutaminase in the central nervous system (CNS) and plays a pivotal role in the CNS injury response. How TG2 affects the cell in response to an insult is strikingly different in astrocytes and neurons. In neurons, TG2 supports survival. Overexpression of TG2 in primary neurons protects against oxygen and glucose deprivation (OGD)-induced cell death and in vivo results in a reduction in infarct volume subsequent to a stroke. Knockdown of TG2 in primary neurons results in a loss of viability. In contrast, deletion of TG2 from astrocytes results in increased survival following OGD and improved ability to protect neurons from injury. Here, a brief overview of TG2 is provided, followed by a discussion of the role of TG2 in transcriptional regulation, cellular dynamics, and cell death. The differing roles TG2 plays in neurons and astrocytes are highlighted and compared to how TG2 functions in other cell types.

Exploiting Solvate Ionic Liquids for Amine Gas Analysis on a Quartz Crystal Microbalance.

We demonstrated in this work the usefulness of solvate ionic liquids SIL 3 and SIL 4 for chemoselective detection of amine gases on a quartz crystal microbalance. This detection of gaseous amines was achieved by nucleophilic aromatic addition reactions with super electrophilic SIL 3 or SIL 4 thin-coated on quartz chips. Starting with inexpensive reagents, functional SIL 3 and SIL 4 could be readily synthesized in two short steps with high isolated yield (81 and 77%, respectively). The QCM platform developed in this work is readily applicable and highly sensitive to low molecular weight amine gases: for propylamine gas at 10 Hz decrease in resonance frequency, the sensitivity of detection using SIL 4 was 5.4 ppb. This simple and convenient assembly of neutral ligands (e.g., 1a and 1b) with Li+ ion to afford room temperature ionic liquids should be of great importance for a myriad of applications. To the best of our knowledge, no example to date of reports based on nucleophilic aromatic addition reactions demonstrating sensitive amine gas detection in solvate ionic liquids on a QCM has been reported. Furthermore, because of the high color intensity of the Meisenheimer complexes formed, our preliminary result showed that SIL 4 loaded on copier paper can be used not only as a portable amine gas sensor but also as a potential invisible ink that is only revealed by amine vapor.

Ultrasound-assisted purge-and-trap extraction for simultaneous determination of low-molecular weight amines and ammonium in high salinity waters by ion chromatography

Direct determination of ammonium and amines in high salinity water samples by ion chromatography using conductivity detection is impossible due to the presence of high potassium and sodium concentrations. This work describes a simple and fast method for the determination of ammonium, monomethylamine and monoethylamine in high salinity waters by ion chromatography. An ultrasound-assisted purge-and-trap extraction system was used to eliminate matrix interferences. This system was optimized using a full two-level factorial (23) design followed by a two-level factorial (22) design. In the first factorial design, the variables: extraction time, concentration of sodium hydroxide solution and analyte mass were tested. In the second factorial design, the mass of each analyte was maintained constant. Parameters of the analytical curves, prepared in different matrices: sulfuric solution and extracts from working standard solutions prepared in water and saline solution were compared. Limits of detection of 0.02, 0.03 and 0.03mgL−1 were found for ammonium, monomethylamine and monoethylamine, respectively. Saline waters from Brazilian oil industry, pre-treated to remove nitrogen compounds, were analyzed. Satisfactory recoveries (93–111%) of the analytes were obtained for all spiked samples. Precision was ≤10% (n=3). The proposed method is adequate for analyzing saline waters containing sodium to ammonium, monomethylamine and monoethylamine concentration ratios up to 56,000:1 and potassium to ammonium, monomethylamine and monoethylamine concentration ratios up to 24,000:1.

Wet impregnation of a commercial low cost silica using DETA for a fast post-combustion CO2 capture process

This work presents an economic and simple method to manufacture low cost, but effective adsorbents for CO2 capture through impregnating DETA to a low cost, porous silica gel. The results have demonstrated that the low cost silica gel impregnated by low molecular-weight amine is stable and work very well at a temperature up to 130°C. The developed adsorbent has a fast adsorption kinetics and can be regenerated at a low temperature. This will significantly reduce the energy used to desorb CO2, therefore the energy penalty. The effect of amine loading on the textural properties, thermal stability, and CO2 capture performance of the impregnated silica gel is also reported in this paper. 10% amine loading gives the best porosity, stability and the highest adsorption capacity.

Development of an analytical method for simultaneous detection of psychotropic phenylalkylamines in hair by LC-MS/MS with a multi-mode reversed-phase column using pH gradient elution

Phenylalkylamine derivatives, such as methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), phentermine, fenfluramine, phendimetrazine, amfepramone, and ketamine, are widely abused recreational or anorectic drugs in Korea, and their abuse has become a serious social problem. Hair is a useful specimen to prove chronic use and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently become a more popular tool for hair analysis due to sensitivity and simplicity in sample preparation. In order to overcome limitations of standard reversed-phase column to separate low molecular weight amines, we adopted a multi-mode reversed-phase column, Scherzo SS-C18, which was composed of strong ionic ligands and C18 ligands, and used pH gradient elution to separate seven psychotropic phenylalkylamines and their metabolites. The essential validation parameters including selectivity, LOD, LLOQ, linearity, intra- and inter-assay precision and accuracy, recovery, and the matrix effect were satisfactory. The LODs ranged from 0.1ng/5mg hair (diethylnorephedrine, fenfluramine, ketamine, and MA) to 0.5ng/5mg hair (amfepramone, MDA, phendimetrazine, and phentermine). The LLOQs were 1ng/5mg hair for all analytes. The developed method was successfully applied to determination of phenylalkylamines in authentic hair samples analyzed previously by a routine gas chromatography/mass spectrometry (GC–MS) method. A good correlation was observed between the two methods, with a slope near one.