Aliphatic Amino Compounds Research Articles

An experimental investigation on the effects of fuel additive on the exhaust emissions of a ferry

This study experimentally investigates the effects of fuel additive on the exhaust emissions and performance of a marine diesel engine installed on a ferry. The fuel additive consisting of hydrocarbon solution of cyclic and aliphatic amino compounds is used to blend the ultra-low-sulfur diesel fuel. On-board measurements of NOx, SO2, CO2, CO, hydrocarbon and particulate matter emissions with and without fuel additive were carried out at different engine loads. The composition and formation of the particles are studied by using scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis. The results show that the fuel additive reduced the emissions of CO, hydrocarbon and particulate matter by 6.5%, 60% and 38%, respectively. The elemental analysis of particles indicates that there are 13 major elements such as C, O, Na, Mg, Al, Si, S, K, Ca, Ti, V, Zn and Fe in the samples. Considering the type of the fuel, the Ca, Fe and N are thought to come mainly from the fuel additive. The composition and components of the diesel particles and also the specific fuel oil consumption are not affected significantly by the fuel additive. Consequently, the fuel additive improves the combustion performance and reduces the CO, hydrocarbon and particulate matter emissions of the engine.

Electrochemical and Spectrophotometric Study of the Hydration of Orthophthalaldehyde and Its Reaction with Amines and Aminoacids

Reactions of orthophthalaldehyde (OPA) with nucleophiles are used in analytical and biologically significant reactions for many years [1, 2]. Besides the analytical method for determination of amino acids, the solution of OPA is broadly applied in hospitals as a disinfecting agent for surgery instruments made from plastics. In the literature, there are several different protocols concerning the composition of the active solutions with different timing of the use. This situation is a consequence of the fact, that the mechanisms are not understood [3] and therefore the processes could not be optimized. OPA as a dialdehyde is a molecule with two communicating redox centers. The ortho-position of the two carbonyls enable intramolecular cyclization of intermediates, hence its reactivity with nucleophiles offers a number of structural and stoichiometric possibilities. In addition to this, hydration of the original structure plays a crucial role, since H2O is, in fact, the most abundant nucleophile in the system. Nevertheless, for the above mentioned use, the reaction of OPA with amines and particularly with amino acids is the most important. Due to the reducibility of carbonyl groups and their nitrogen analogues, the electrochemical approach is favorable for this mechanistic investigation. Besides the hydration(dehydration studies, the first series of experiments were focused on the reaction of OPA with aliphatic amino acids: eight simple amino acids with only one α-amino group (glycine, alanine, leucine, isoleucine, valine, norvaline, aminobutyric and aminoisobutyric acid), one ester preventing zwitterionic equilibrium (glycine ethyl ester) and lysine with two amino groups. Polarography and spectrometry were the main used techniques. Measurements were done in two phosphate buffers (pH 7,90 and 11,20) with pH above and under the pKa of amino groups in used amino acids. It was found out that the hydration of orthophthalaldehyde plays a very important role. If stock solution of OPA is prepared in acetonitrile, then in aqueous phosphate buffer the hydration of OPA competes with the reaction with amino acids more than it was expected in published articles [4]. If stock solution of OPA is prepared in water, the reaction with amino acids is faster than with non-aqueous stock solution. The main result is that according to our measurements the reactive species is not OPA as dialdehydic form but its (mono)hydrated form. At present the investigation continues with various aliphatic amino compounds, the relationship with hydration of OPA and the reaction products are presented and discussed. Acknowledgments The research was supported by GA CR (project No. 13-21704S) and by institutional support (RVO: 61388955).

Microwave-Assisted Synthesis of Benzothiazoleurea Derivatives

A simple and efficient method has been developed for the synthesis of 1-substituted-3-(4-chlorobenzo[d]thiazol-2-yl) ureas (5), from substituted aromatic or aliphatic amino compounds and phenyl 4-chlorobenzo[d]thiazol-2-yl carbamate 4 using microwave irradiation without phosgene in good yields. The title products were characterised by 1H NMR, ESIMS, and elemental analysis.

Oxide Radical Anion Reactivity with Aliphatic Amino Compounds in Aqueous Solution: Comparison of H−Atom Abstraction from C−H and N−H Groups by •O- and •OH Radicals

One-electron oxidants react with H2N−CHRR‘ amino compounds by electron transfer (ET), and direct H abstraction from N−H and C−H, giving respectively, aminium (+•NH2CHRR‘), aminyl (•NH−CHRR‘), and α-C-centered radicals (H2N-•CRR‘). The yields of these species from •O- reactions with the anions of glycine (Gly-), alanine (Ala-), and α-methylalanine (MeAla-) and with methylamine (MeNH2) have been investigated at pH ≥ 13. The results indicate an ET process is negligible. Aminyl and α-C-centered radicals appear to be formed only by direct H abstraction reactions. In line with this, the ratios of the overall rates of H abstraction from N−H and C−H, kN(-H•)/kC(-H•), for •O- reacting with different amino compounds decrease with C−H bond dissociation enthalpy (BDE) and thus follow the pattern expected for direct abstraction reactions. In contrast to •O-, the conjugate •OH radical produces significant yields of aminium radicals by ET, which evidently contribute to aminyl radical formation by subsequent proton loss from nitrogen. Thus, the kN(-H•)/kC(-H•) ratios for •OH are higher than those for •O- and do not decrease regularly with C−H BDE. Formation of α-C-centered radicals via ET and subsequent proton loss from a C−H group of the aminium radical is much less likely. The overall rates of H abstraction from C−H sites by both •OH and •O- are found to increase with the exothermicity of the reaction. Because of its spherical symmetry the steric factors for •O- reactions are larger than those for •OH, but in most cases this appears to be compensated by more favorable potential energy surfaces stemming from the 36 kJ mol-1 greater exothermicity of •OH reactions. •O- reactions with charged species are of course also susceptible to the effects of Coulombic interactions.

Reaction of the epoxide groups of the copolymer trimethylolpropane trimethacrylate‐glycidyl methacrylate with aliphatic amino compounds

AbstractFunctional macroporous polymers have been synthesized from copolymers of trimethylolpropane trimethacrylate (TRIM) and glycidyl methacrylate (GMA). The accessibility of the epoxy groups has been investigated by reaction with dialkylamines and diamines of different chain lengths. The obtained yield of reacted amine was approximately 80% for small molecules. The yield, and accessibility, decreased when the chain length or bulkiness of the reagent increased. The swelling ability in water of the functional polymers increased compared with the original copolymer.

Reactive polymers. VIII. Reaction of the epoxide groups of the copolymer glycidyl methacrylate – ethylenedimethacrylate with aliphatic amino compounds

AbstractThe reaction of macroporous copolymers glycidyl methacrylate – ethylenedimethacrylate with ammonia, primary and secondary amines, diamines and hydroxyalkyl amines leading to products with wide applicability was investigated. The reaction can be carried out without or with solvent, water being quite sufficient as the latter. The effects of amine concentration, substituents, temperature and type of the solvent on the reaction course were examined. The reaction product with dimethyl amine and 2‐hydroxyethyl amine was alkylated consecutively, and a strongly basic anion exchanger of second type was obtained.

Myeloperoxidase of human neutrophilic granulocytes as chlorinating enzyme.

Two pH‐dependent spectral forms of myeloperoxidase have been described. Their absorption maxima in the Soret region were at 432 nm and 426 nm for acid and neutral pH, respectively. Chloride exerts an influence on the spectrum of peroxidase, mainly in acidic medium. Dissociation constants for the myeloperoxidase chloride complex and Km values for chloride in the chlorination reaction catalyzed by myeloperoxidase were determined. It was found that the affinity of chloride ions to the enzyme decreases with an increase of pH.Catalytic activity of myeloperoxidase in the reaction of incorporation of 36Cl into aliphatic amino compounds such as taurine, β‐alanine, ethanolamine and diethanolamine was investigated. Primary amino groups were chlorinated to N‐mono‐ or dichloramines, depending on the pH of the medium. The method of determination of 36Cl‐labelled chlorocompounds in the presence of excess Na36Cl was described.The role of myeloperoxidase as chlorinating enzyme in the mechanism of the bactericidal effect on bacteria phagocytized by neutrophilic granulocytes is discussed.

Silver complexes of some aliphatic amino-compounds

Formation constants for the silver complexes of some aliphatic amino-compounds have been determined at 20° by use of a pH-titration technique in constant salt background medium, ionic strength 0·5. A weighted least-squares treatment of the ligand number experimental results, with the aid of a digital computor, was used to obtain these constants. The overall stability constants of the complexes were also obtained from independent silver–silver iodide electrode-potential measurements; and finally, the acid dissociation constants of the ligands were determined.

Aliphatic Amino Compounds as Inhibitors of Plasminogen Activation

ConclusionsSeveral aliphatic amino compounds are inhibitors of activation of plasminogen by streptokinase in vitro. The most potent of these are amino acids with a carbon chain length of 4 to 8 and with the amino group in the omega position. The significance of these findings is discussed.The technical assistance of Gunilla Martinsson is appreciated.

Coupling of Diazonium Complexes from an Aliphatic Base

THE formation of diazonium complexes from unsaturated amines is not a unique property of the aromatic series. Many, but not all, unsaturated heterocyclic amines respond similarly1. With aliphatic amino-compounds, nitrous acid, under certain conditions, may give a diazo-grouping but not an ionizable diazo-derivative. In the literature it would appear that aminoguanidine is the only straightchain compound so far recorded as being in line with the aromatic amines. Even in this example the tendency is to form an intermediate heterocyclic compound, and it is only under special conditions that a straight-chain diazonium derivative is obtained.