Amine Type Research Articles

Separation, synthesis, and cytotoxicity of a series of mogrol derivatives

Four metabolites of mogrol were separated, identified and characterized. Their antitumor activity was evaluated, and the results showed side chain modification would probably enhance the cytotoxicity. Therefore, three types of amines, alcohols and rigid planar derivatives were synthesized. Compounds 20 and 21 containing a tetrahydro-β-carboline structure at the end of the side chain exhibited IC50 values around 2–9 μM against A549 and CNE1 cell comparing with 80–90 μM of mogrol. Structure analysis suggested that the perhydrocyclopentanophenanthrene moiety and the tetrahydro-β-carboline moiety could probably enhance the activity through an intramolecular synergistic effect.

Evaluation the Effect of Amine Type on the Non-isothermally Derived Activation Energy for the Interaction of 3 Antidepressant Drugs with Lactose.

Purpose: Evaluation of drug-excipients compatibility is an important stage during preformulation studies. In the present research, differential scanning calorimetry (DSC) at different heating rates (2.5, 10, 15°C/min) was applied for the kinetic evaluation of fluvoxamine (FLM), sertraline (SER) and doxepin (DOX) binary mixtures with lactose. Methods: Solid state kinetic parameters of the mixtures were calculated using two different thermal methods including ASTM E698 and Starink and the effect of amine type (pKa value) was investigated based on the calculated activation energies. Results: Based on obtained results mean activation energy calculated for FLM, SER and DOX with lactose using ASTM E698 and Starink methods are equal to 335.23, 132.02 and 270.99 kJ/ mol respectively. Conclusion: Results showed that the probability of drug-lactose interaction is higher in the SERlactose mixture in comparison with other two antidepressant drugs which is consistent with their pKa values.

Cu(0) Wire-mediated Single-electron Transfer-living Radical Polymerization of Oligo(ethylene oxide) Methyl Ether Acrylate by Selecting the Optimal Reaction Conditions

The efficient Cu(0) wire-catalyzed single-electron transfer-living radical polymerization (SET-LRP) in organic solvents and mixtures of the organic solvents with water has been thoroughly investigated. Oligo(ethylene oxide) methyl ether acrylate was used as an exemplar oligomer monomer to determine the optimum polymerization conditions for rapid, controlled, and quantitative production of well-defined polymers. The effects of Cu(0)-wire length (12.5 or 4.5 cm), ligand type (tris(dimethylaminoethyl)amine, Me6-TREN, or tris(2-aminoethyl)amine, TREN), and solvent type (dipolar aprotic solvents, cyclic ethers, alcohol, or acetone) on the polymerization have been evaluated. Kinetic experiments were performed for all polymerizations to assess the “living” behavior of each system employed. Importantly, TREN could be used as a replacement for Me6-TREN in Cu(0) wire-catalyzed SET-LRP of oligomer monomer, which probably provides the most economical and efficient methodology since TREN is 80 times less expensive than Me6-TREN. The high chain-end fidelity of resulting polymer was experimentally verified by thiol-Michael addition reaction at the α-Br chain end and subsequent chain extension with methyl acrylate.

Fabrication of amine functionalized graphene oxide – AgNPs nanocomposite with improved dispersibility for reduction of 4-nitrophenol

In the present work, graphene oxide (GO) was synthesized through modified Hummer's method and the covalent functionalization of GO was achieved via amino moiety using N,N′-dicyclohexylcarbodiimide (DCC) as coupling agent and ethylenediamine (EDA) & 1,3-diaminopropane (DAP) as amino precursors. The amino functionalized GO served as nucleation and growth sites for silver nanoparticles. These two amino functionalized graphene oxide-AgNPs were compared based on the chain length of the alkyl-diamine and metal loading capacity. Further, these two nanocomposites were characterized using FTIR, UV, Raman, XPS and TEM analyses. We reported that these alkyl-diamine-functionalized graphene oxides had superior dispersibility in different polar solvents with reduced agglomeration of Ag nanoparticles and had control over the size of Ag nanoparticles in the range of 5–10 nm. The catalytic efficiency of these two types of amine functionalized GO-AgNPs nanocomposite were assessed based on the reduction of 4-nitrophenol. The reduction outcomes revealed that the kobs value for DAP functionalized AgNPs (7.548 × 10−4 s−1) was comparatively superior than GO-EDA-AgNPs (3.345 × 10−4 s−1) due to the variation in chain length. Optimization of parameters like [substrate], [NaBH4] and catalyst load was also investigated and found to possess influence on kobs values.

Alternative diesel fuels with high hydrogen content in their molecular structures

Alternative fuel components have a continuously growing use worldwide. Hydrocarbons with high hydrogen to carbon ratio in their molecular structures are the most suitable alternative fuels. In this paper the special hydrocracking of waste fatty acids and waste lard to paraffin mixtures over sulfided NiMoP/Al2O3 is presented. The effect of feedstock additives was investigated on the catalyst performance, such as activity, selectivity, product yield and catalyst lifetime. It was concluded that coke precursors, which were formed from olefinic components reduced the catalyst performance. Olefins were generated as intermediates of hydrocracking but could be present also in the feedstocks. Based on the results it was also concluded that application of amine and phenol type additives in the feedstocks inhibited the formation of coke precursors and coke. Results of catalytic tests having length of ca. 1000 h were compared. Applying 200 mg/kg additive in favorable combination resulted in about 21–37 wt% increase in the yield of target products relative to that using feedstock without additives. The obtained target products were rich in n-paraffins and represented diesel blending components of >85 cetane number. Various ideas are proposed for the utilization of the obtained bio-paraffin mixture.

Enhanced adsorption performance of Reactive Red 120 azo dye from aqueous solution using quaternary amine modified orange peel powder

Orange peel powder was chemically modified to enhance quaternary amine type content on the surface of adsorbent which was named as quaternary amine modified orange peel powder (QAMOPP). The effecting parameters on adsorption of Reactive Red (RR) 120 such as pH (2.0–9.0), contact time (0–300 min), adsorbent dosage (0.01–0.07 g/30 mL), initial RR120 concentration (100–1000 mg/L) and temperature (298–338 K) were studied. The QAMOPP was extensively characterized for its surface chemical bonding, morphological structure, and specific surface area, total pore volume and average pore diameter by employing FTIR, SEM and BET analysis. The experimental adsorption kinetic data followed the pseudo-second-order kinetic model equation with a regression coefficient of >0.9941 for all studied temperatures. The activation energy (Ea) is calculated to be 12.1 kJ/mol by using the Arrhenius equation. Adsorption isotherms of RR120 on QAMOPP were correlated with two- and three-parameter non-linearized isotherm equations viz. Langmuir, Freundlich, Dubinin-Radushkevich (D-R), Temkin, Sips, Toth, Khan and Redlich-Peterson (R-P). It was observed that the Langmuir (R2 = 0.9996) and Khan (R2 = 0.9991) were the best fit isotherm models to predict RR120 adsorption onto QAMOPP. pH study revealed that the adsorption capacity decreased with an increase in pH of the solution. Optimum adsorption of RR120 onto QAMOPP was observed at pH 2.0 (344.8 mg/g). The adsorption performance of QAMOPP increased with contact time until 110 min, when it became nearly constant. The negative values (−1.9114 to −5.9208 kJ/mol) of ΔGo, the positive values (0.102 kJ/mol K and 28.4 kJ/mol) of ΔSo and ΔHo parameters indicate that the adsorption of RR120 onto QAMOPP was spontaneous, feasible and endothermic, respectively. Desorption experimental studies showed optimum RR120 recovery (92%) when 0.1 M NaOH was used as an eluent. Hence to remove RR120 from aqueous media QAMOPP can be considered as a powerful alternative adsorbent material.

Effects of Microorganism Count and Physicochemical Properties of Tulum and Kashar Cheeses to Biogenic Amine Formation

In this research, biogenic amine types and quantity of Tulum and Kashar cheeses were determined. In addition, the relationship between biogenic amines and some microbiological-chemical properties of cheese samples were investigated. The contents of tryptamine, phenylethylamine, putrecine, cadaverine, histamine, tyramine of totally 40 samples (20 of each cheese) were examined. While only one sample of Tulum cheeses had no biogenic amines, different levels of biogenic amines were determined in other samples. No significant relation was confirmed between the biogenic amine quantity and total aerobic mesophilic bacteria, lactic acid bacteria, enterococci bacteria count, but there was a correlation between some biogenic amine contents and chemical properties which are tyrosine, lactic acid, pH, protein and ripening coefficient. Biogenic amine levels determined in the cheeses found below hazard limit values according to what legal limit.

Development of high-performance polymer membranes for CO2 separation by combining functionalities of polyvinyl alcohol (PVA) and sodium polyacrylate (PAANa)

In the present study, integrated polymers having gas barrier and water sorption properties were prepared by effectively blending two types of polymers to fabricate membranes for high-performance CO2 separation. Namely, composite polymers were prepared as a new membrane material by uniformly blending polyvinyl alcohol (PVA), a gas barrier polymer, with sodium polyacrylate (PAANa), a water-absorbing polymer. The optimal PVA/PAANa blending ratio was determined by evaluating the thermal properties of the prepared polymer blend and the CO2 separation performance of the polymer blend membrane. When amine type additives such as polyamidoamine (PAMAM) dendrimer or polyallylamine (PAAm) were added to the prepared PVA/PAANa, the separation performance of the produced separation membrane increased. Applying a carbonate coating onto the PVA/PAANa membranes containing additives further increased the separation performance and selectivity of the membranes. These results demonstrated that the PVA/PAANa membranes prepared in this study, which featured both gas barrier and water absorption properties, could be used as high-performance membrane materials for CO2 separation.

Glycoconjugates coated gold nanorods based novel biosensor for optical detection and photothermal ablation of food borne bacteria

Foodborne bacterial species have been identified as the major cause in most of the severe pathogen related diseases. Conventional methods like plating and enzyme-linked immunosorbent assay (ELISA) are time overriding and laborious. Fast detection of bacterial species in food is a proximate obligation to guarantee food safety. Nanotechnology has emerged as a great field in case of rapid detection of pathogens in recent years. In the present work, gold nanorods, (AuNRs) based sensor was developed for swift and sensitive detection of foodborne bacteria. AuNRs has good electro-optical properties due to its Near-Infrared (NIR) absorption and scattering in surface plasmon resonance (SPR) wavelength regions. By exploiting the sugar based adhesion properties of bacteria, the sugar capped AuNRs can be used as potential nanobiosensor to detect the food borne bacteria. Polyethylene glycol (PEG) coated AuNRs were covalently functionalized with different types of amine terminated sugar using EDC coupling reaction. The sensitivity of synthesized nanobiosensor was probed by lectin binding assay and also with food borne bacteria (Escherichia coli) by using spectrophotometric and microscopic techniques. Pseudomonas aeruginosa was also used to probe the specificity of our synthesized biosensor through lectin-sugar interaction. Due to the specific interaction of sugar coated probe with foodborne bacteria, our nanoprobe has shown significant and selective photoablation of targeted bacteria. This nanorod based nanobiosensor can be an ideal candidate for optical detection and ablation of foodborne bacteria.

A very sensitive and highly selective organic selector in CNTs composite chemiresistive for efficient differentiation of organic amine vapours

With the call for the IoE (Internet of Everything), stable and efficient electric noses/tongues have become the most critical part of the sensor network. Identifying target gases efficiently and rapidly at ambient air becomes a focus on sensor research. We designed a chemiresistive sensor based on a composite of a specific selector and single-walled carbon nanotubes (SWNTs) for the detection and differentiation of organic amine vapours in air (25 ℃, 55% RH). The synergetic combination of F4-TCNQ (2,3,5,6-Tetrafluoro-7,7',8,8'-tetracyanoquinodimethane) and SWCNTs could modulate the electrical properties of sensor leading to the enhancement of response up to ppb-level for primary amine vapor detection. Different from traditional chemiresistive sensor, this sensing materials exhibit unique differences in response to different types of amines thought different mechanisms. We have proven the practical possibilities through the detection of the simulated complexed environmental atmosphere in industrial production. Furthermore, we explored the working mechanism of high-performance sensors, which could provide theoretical guidance for sensor design for more commercial applications. This study provided a simple, convenient, and highly efficient practical method for organic amine detection at ambient air for real-life applications.

Corrosion Performance of Valve Seat Hardfacing Materials in Amine Environment of Boiler Feed Water Service

As the valve seat hardfacing materials in boiler feed water service of coal power plants, the corrosion behavior of Stellite 6 alloy and 17-4PH stainless steel in amine solutions is studied using electrochemical test methods. Morpholine, cyclohexylamine, and sodium hydroxide (NaOH) solution with pH 9.5 are selected to be the corrosive media. The first solution is a typical amine medium, the second one is selected to examine if different amine media with the same pH can result in any change in the corrosion behavior of these materials. Sodium hydroxide is chosen to offset the effect of pH change. Polarization test is performed on Stellite 6 alloy and 17-4PH stainless steel under the low potential varying from –0.4 VSCE to 1.2 VSCE and is also conducted under a constant high potential (4 VSCE) in order to fail the sample surfaces. The polarization curves 17-4PH stainless steel from the low potential tests show an apparent passivation region indicating a protective oxide film formed on the sample surface, but Stellite 6 alloy only exhibits a tendency to passivate. The Stellite 6 alloy and 17-4PH stainless steel samples after the failure tests under the high potential (4 VSC) are analyzed using SEM/EDX. It is shown that the former is severely corroded in all the solutions while the latter is only corroded in morpholine solution and it is very corrosion-resistant in sodium hydroxide solution. The corrosion mechanisms of Stellite 6 alloy and 17-4PH stainless steel in amine solutions are discussed with assistance of the Pourbaix diagrams.

MXenes support isolated catalytic metal atoms

A simple preparation procedure converts ultrathin sheets of titanium carbide to a material that supports isolated platinum atoms, yielding a highly active catalyst that uses CO2, a greenhouse gas, to make valuable organic compounds (J. Am. Chem. Soc. 2019, DOI: 10.1021/jacs.8b13579). A common procedure for preparing MXenes, a family of 2-D metal carbides and nitrides, from mixed-metal carbide starting materials yields a related carbide dotted with individual titanium vacancies. Chen Chen of Tsinghua University and coworkers proposed that treating the defective material with a platinum salt would be an easy way to pin isolated platinum atoms across the MXene surface. So the researchers prepared the material, confirmed its structure, and tested its ability to catalyze reactions. They found that it was especially effective at mediating formylation of many types of amines with CO2 under mild conditions. For example, exposing aniline to CO2 at atmospheric pressure in the presence of the

Carbon-SO3H catalyzed expedient synthesis of new spiro-[indeno[1,2-b]quinoxaline-[11,2′]-thiazolidine]-4′-ones as biologically important scaffold

In this report, we have described a convenient and eco-compatible approach for synthesis of new hybrid spiro[indeno[1,2-b]quinoxaline-[11,2′]-thiazolidine]-4′-ones (4a-k) via multi-component reaction of indeno[1,2-b]quinoxalinone, α-mercaptocarboxylic acids and various types of amines using urea-choline chloride as green deep eutectic solvent and carbon-SO3H as a solid acid catalyst. This new protocol produces a thiazolidine ring attached to indeno[1,2-b]quinoxaline through spiro carbon in good to excellent yields. The advantages of this protocol are avoidance of toxic and harmful catalyst and solvents further both catalyst and DES were recovered from the reaction mixture quantitatively and reused several times. Synthesized compounds were characterized on the basis of spectral and single crystal X-ray analysis. The prepared catalyst was characterized by FT-IR, SEM, and X-ray diffraction method.

Sustainable Optimization of Natural Gas Sweetening Using A Process Simulation Approach and Sustainability Evaluator

Abstract Natural gas need to undergo processes in order to reach its highest purity. The objective of this paper is to determine which type of amines that can give a high removal percentage of H2S and CO2 from the gas stream and to evaluate the plant by using sustainability evaluator. Impurities such as carbon dioxide (CO2) and hydrogen sulfide (H2S) can be found inside natural gas and removal of these impurities are crucial as it can cause corrosion hence affecting the market value of natural gas. Mixtures of different amines are widely used for the removal of H2S and CO2 in gas sweetening process. In this study, three different types of amines which are Monoethanolamine (MEA), Diethanolamine (DEA) and Methyldiethanolamine (MDEA) are added to Aspen HYSYS® simulation in order to determine the efficiency of these three amines. This provides a fluid package where it is related with the process which is Acid Gas package. Data from the simulation were extracted and fed into sustainability evaluator which includes the economic, environmental and social analysis. Based on the simulation, it is proved that MEA is the most effective amine in removing CO2 and H2S from the natural gas stream. The most sustainable plant is among the three amines is MDEA. In a nutshell, sustainability evaluator can be one of the best evaluator to check the sustainability of the plant.

Influence of Surface Migration of 6PPD as an Amine Type Antioxidant on Ozone Resistance of Vulcanized Rubber

Influence of Surface Migration of 6PPD as an Amine Type Antioxidant on Ozone Resistance of Vulcanized Rubber

Manipulating selectivity of covalently-bonded hyperbranched anion exchangers toward organic acids. Part I: Influence of primary amine substituents in the internal part of the functional layer

Three covalently-bonded poly(styrene-divinylbenzene)-based (PS-DVB) hyperbranched anion exchangers prepared using primary amines with carboxylic, sulfonic or 2-hydroxyethyl substituents in the internal part of the functional layer were studied and compared for evaluating the effect of amines substituents on the chromatographic performance of the stationary phases. The hyperbranched coating was created on the surface of aminated PS-DVB substrate by repeating the modification cycles including alkylation with 1,4-butanediol diglycidyl ether (1,4-BDDGE) and amination with primary amine; glycine, taurine (2-aminoethanesulfonic acid) or ethanolamine were used in the first cycle, and 4 more cycles were conducted with methylamine (MA). The influence of the structure and type of primary amine used in the first cycle on the retention and selectivity toward inorganic anions, short-chain carboxylic acids, and polyphosphates was investigated using hydroxide eluent. The effect of temperature on the separation of organic acids was also studied for all stationary phases, which revealed the possibility to control and improve resolution for some pairs of analytes.

Addressing the conundrums of p-phenylenediamine hair dye allergy by applying Friedmann's principles of contact sensitization.

In the first conundrum, permanent hair dyeing involves the use of aromatic amines such as p-phenylenediamine (PPD), whose oxidation is pivotal to the dyeing process, but also generates potent allergens. Despite prolonged efforts by industry to search for safer alternatives, hair dyeing is still reliant on this type of aromatic amine. In the second conundrum, patch testing with 1% PPD remains the most useful screen for hair dye contact allergy. However, there is a very small but real risk of actively sensitizing the patient. Lowering the PPD concentration below 1% significantly reduces test sensitivity and diagnostic utility. Here, we argue that by applying Friedmann's principles of contact sensitization each conundrum can be addressed from a new perspective. These principles indicate that, when the exposed area of skin is small (<1 cm2 ), induction of contact allergy is sharply reduced, whereas elicitation of allergy is unaffected. Careful reflection on this principle suggests that we can predict where hair dye sensitization is most likely to occur, indicates a strategy to reduce the chance of contact sensitization occurring in consumers as a result of hair dyeing, and how we might mitigate the risk of active sensitization resulting from diagnostic patch testing.

Synthesis and Cytotoxic Activity of Some Novel Thieno[2,3-d:4,5-d’]Dipyrimidine Derivatives

Synthesis of some novel tricyclic compounds bearing thienodipyrimidine moiety by the reaction of ethyl 6-amino-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidine-7-carboxylate (1) with different types of aromatic amines to give the corresponding carboxamide derivatives 2-11, which cyclized with triethyl orthoformate in acetic anhydride to afford thieno[2,3-d:4,5-d']dipyrimidine derivatives 12-15 is described. Similarly, thieno[2,3-d:4,5-d']dipyrimidine derivative 17 was also prepared via the reaction of carboxamide derivative 2 with chloroacetyl chloride in chloroform to give thieno[3,2-d]pyrimidine-7-carboxamide derivative 16, followed by a cyclization in boiling acetic anhydride. The structure of these compounds was confirmed on the basis of their spectral and analytical data such as IR, 1H-NMR, 13C-NMR spectroscopy and mass spectral data. The synthesized compounds were screened for their cytotoxic activity.

Preparation and evaluation of amine terminated polyether shale inhibitor for water-based drilling fluid

Facing the problems of shale hydration, swelling and borehole wall instability in shale gas drilling, a new type of amine terminated polyether (ATPE) shale inhibitor used in water-based drilling fluid is successfully synthesized through the method of leaving group. Using the yield of ATPE as index, orthogonal experiments are designed to determine the optimal reaction conditions. When the mole ratio of polyethylene glycol tosylate (PEG-OTs)/ethylenediamine is 1/3.6, mole ratio of PEG-OTs/triethylamine (acid binding agent) is 1/4, reaction time is 3.5 h and reaction temperature is 60 °C, the yield of ATPE is 91.12%. The structure and molecular weight of polyethylene glycol (PEG-400, a kind of oligomer), PEG-OTs and ATPE are characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy (H1-NMR) and time of flight mass spectrometer. The characterization results show that the ATPE has a reasonable molecular weight, and the both hydroxyls of PEG-400 have been replaced by ethylenediamine. The inhibition property of ATPE, potassium chloride (KCl), potassium formate (KCOOH), methane-siliconic acid (FMS-1) and polymeric alcohol (JLX-B) are comparatively evaluated through shale rolling dispersion experiment, linear expansion experiment and laser particle size test. The results show that the ATPE has a better shale inhibition property than traditional inhibitors. The drilling fluid system performance evaluation results show that the system has good engineering application value with excellent rheological property, low fluid loss and good shale inhibition property, which guarantee the well-bore stability in shale gas drilling.

A combined experimental and theoretical study on gas adsorption performance of amine and amide porous polymers

In this manuscript, we report synthesis, characterization and application of amine and amide type covalent organic frameworks as CO2 adsorbent materials at various isotherms and wide pressure conditions. Furthermore, we also report a detailed density functional theory investigation of the studied adsorbents in order to explain their adsorption behaviors and provide comparisons with experimental results. The objective of this work was to investigate custom design porous polymers by building amine and amide functionalities in the final structures, whether they have efficient CO2 capturing performances at wide process conditions that covers both low and high pressure end applications to cover either pre- or post-combustion processes. On the other hand, energy storage performances of these materials were tested by performing H2 sorption experiments as well. Two porous polymers, namely COP-9 and COP-10, were characterized with BET, TGA and FTIR to evaluate the physical properties of studied porous polymers and then were tested for CO2, N2 and H2 adsorption both at low and high pressures. Studied materials were found to have compelling adsorption capacity mostly at high pressures and have very good selectivity for CO2/N2 and CO2/H2 respectively.