Alanine Complexes Research Articles

Development of optical sensor for the detection of alanine

• The fluorescent indole based organic sensor (IP) was synthesized by a simple condensation method with moderate yield. • The detection of alanine (ALN) by the IP probe using colorimetric and fluorimetric method. • Probe IP was selectively detects ALN with in the presence of interfering other biomolecules. Indole based organic compound represents the key for disease causing biomolecule and constitute the core of valuable compounds exhibiting biological activities. The synthesized indole based organic probe (IP) detects alanine selectively in aqueous medium at pH 7.2 in the presence of other biomolecules with an excellent lower detection limit of 0.3x10 -7 mol/L. The experimental observation was further studied using density functional theory and the results show the stability of IP…Alanine complex.

Synthesis, Characterization, and Non-Covalent Interactions of Palladium(II)-Amino Acid Complexes.

The reaction of palladium(II) acetate with acyclic amino acids in acetone/water yields square planar bis-chelated palladium amino acid complexes that exhibit interesting non-covalent interactions. In all cases, complexes were examined by multiple spectroscopic techniques, especially HRMS (high resolution mass spectrometry), IR (infrared spectroscopy), and 1H NMR (nuclear magnetic resonance) spectroscopy. In some cases, suitable crystals for single crystal X-ray diffraction were able to be grown and the molecular structure was obtained. The molecular geometries of the products are discussed. Except for the alanine complex, all complexes incorporate water molecules into the extended lattice and exhibit N-H···O and/or O···(HOH)···O hydrogen bonding interactions. The non-covalent interactions are discussed in terms of the extended lattice structures exhibited by the structures.

C2 symmetric copper (II) complexes of l-valine and l-phenyl alanine based chiral diimines for catalytic asymmetric Henry reaction

New C2 symmetric chiral diimines were synthesized from the amino acids l-valine and l-phenyl alanine. In situ copper (II) complexes of the chiral diimine ligands were found to catalyze asymmetric Henry reaction. The chiral nitro aldols were formed in excellent yield (99%) and ee (99%). The synthetic utility of the chiral catalysts were screened with various substituted prochiral aromatic and heteroaromatic aldehydes. Possible catalytic cycle for the chiral diimine copper complex catalyzed asymmetric Henry reaction has been proposed. The stereoselectivity of the asymmetric Henry reaction was discussed based on the transition state in the catalytic cycle.

Defect-Engineered 3D Cross-Network Co3O4–xNx Nanostructure for High-Performance Solid-State Asymmetric Supercapacitors

A 3D cross-network Co3O4–xNx nanostructure is obtained from the cobalt–alanine complex (Co(C3H5O2N)2) by amino acid self-assembly and subsequent pyrolysis. In this process, Co(C3H5O2N)2 forms a 2D ...

Synthesis, spectral characterization, thermal behavior and biological activities study of ternary metal complexes of alanine and 1,8-diaminonapthalene with Co(III), Ni(II), Cu(II), Zn(II) and Cd(II)

Ternary metal complexes derived from different amino acids and aromatic amines are widely employed as biologically active materials, such as antibacterial, antifungal and antioxidant agents. Considering the importance of metal complexes, some ternary complexes have been synthesized by the reaction of cobalt(III) nitrate, nickel(II) chloride, copper(II) chloride, zinc(II) chloride and cadmium(II) chloride with alanine (as a primary ligand) and 1,8-diaminonapthalene (as a supporting ligand) in water- ethanol mixed medium. This metal ligand complexes were characterized by using suitable instrumental techniques. Complexometric, gravimetric and iodometric methods were used to estimate the metal content of the complexes. The IR spectra demonstrated that interactions between the metal ions and ligands occurs through N and O of alaninato ion and N(1,8) of 1,8-diaminonapthalene. The magnetic moment values and characteristic absorption bands that appeared in UV–Vis spectrophotometry corresponds to the square planar geometry for all complexes. The metal complexes have been screened for antibacterial activity against some gram negative (such as- P. aeruginosa. E. coli) and some gram positive (such as- B. subtilis, B. cereus) bacteria and for antifungal activity against Saccharomyces cerevace, Candida albicans and Aspergillus niger. Nickel, zinc and cadmium complexes show antibacterial and antifungal activity whereas cobalt and copper complexes are almost insensitive towards microorganism. Beside this, all the complexes showed significant antioxidant activity.

Synthesis, Characterization, and Biological Evaluation of Chromium(III) Complexes of Alanine and Valine

Two metal-amino acid complexes, Cr(III)-alanine and Cr(III)-valine, were synthesized and characterized by IR spectroscopy, powder X-ray diffraction (XRD) analysis, magnetic susceptibility, and molar conductivity measurements. Molar conductivity measurements indicated that the composition of the metal complexes corresponds to a metal-amino acid ligand ratio of 1:3. The IR spectra indicated that the amino acids act as bidentate ligands with coordination involving the carboxyl oxygen and the nitrogen of the amino group. Magnetic susceptibility measurements revealed a six-coordinate local symmetry around the Cr(III) ions which depicted that the complexes were paramagnetic with magnetic moment values ranging from 5.10 to 6.00 BM. Powder XRD studies confirmed that the amino acid complexes were crystalline with monoclinic crystal structure. The in vitro biological activity of the investigated chromium(III) complexes with alanine and valine was tested against Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli. All the microorganisms were standardized using 0.5 McFarland standard. The antimicrobial studies showed that the ligands were biologically active with an inhibition zone range of 10-17 mm and their metal complexes showed significantly enhanced antimicrobial sensitivity with an inhibition zone range of 12-21 mm. The standard drug showed slightly better activity with an inhibition zone range of 24-38 mm.

Preparation, Investigation and Enzymatic Activity of Mixed Iigand Complexes of Mefenamic Acid and Phenyl Alanine with some Transition Metal

Preparation, Investigation and Enzymatic Activity of Mixed Iigand Complexes of Mefenamic Acid and Phenyl Alanine with some Transition Metal

Effect of Moisture Content on the Diverse Structure State of the Octanoyl Alanine Metal (Mg, Ca) Complexes

Octanoyl alanine ligands and metal ions (Mg2+, Ca2+) form metal complexes of octanoyl alanine through chemical coordination bonds [1]. According to the acid base reaction and the Lewis acid-base theory[2], the molecule or ion of the central atom or ion (collectively called the central atom) and the ligand (called ligand) around it, completely or partially by the coordination bond to form metal complex. These octanoyl alanine complexes are soluble in water and easily ionize into internal coordination ions and external ions, while the ligands and central atoms do not ionize in the inner boundary. The octanoyl alanine magnesium and calcium complexes belongs to the amino acid metal complexes, which can be widely used in daily life, industrial production and life science in the future application. Recently, with the rapid development of amino acid metal complexes [3-7], it is not only associated with inorganic compounds and organometallic compounds, but also overlaps with the chemistry, coordination catalysis and molecular biology of the current chemical frontiers [8-10]. In this paper, [C10H20NCO3]2M type metal complexes prepared by combining octanoyl alanine ligand with metal ions containing functional group COOH, the influence of water content on the DSC curve and surface morphology of metal complexes was studied, and the information of the diversified structure state of the materials complex can be obtained.

Nitrogen‐Doped Cobalt Oxide Nanostructures Derived from Cobalt–Alanine Complexes for High‐Performance Oxygen Evolution Reactions

AbstractTaking advantage of the self‐assembling function of amino acids, cobalt–alanine complexes are synthesized by straightforward process of chemical precipitation. Through a controllable calcination of the cobalt–alanine complexes, N‐doped Co3O4 nanostructures (N‐Co3O4) and N‐doped CoO composites with amorphous carbon (N‐CoO/C) are obtained. These N‐doped cobalt oxide materials with novel porous nanostructures and minimal oxygen vacancies show a high and stable activity for the oxygen evolution reaction. Moreover, the influence of calcination temperature, electrolyte concentration, and electrode substrate to the reaction are compared and analyzed. The results of experiments and density functional theory calculations demonstrate that N‐doping promotes the catalytic activity through improving electronic conductivity, increasing OH− adsorption strength, and accelerating reaction kinetics. Using a simple synthetic strategy, N‐Co3O4 reserves the structural advantages of micro/nanostructured complexes, showing exciting potential as a catalyst for the oxygen evolution reaction with good stability.

Arrangement and nature of intermolecular hydrogen bonding in complex biomolecular systems: modeling the vitamin C---L-alanine interaction

Vitamin C is known as an essential dietary supplement and implicated in diverse biological processes. We present here a theoretical study on the nature of hydrogen bonding of vitamin C in biological systems. For this reason, the complexes of vitamin C (VC) with neutral and zwitterionic L-alanine (as the simplest chiral amino acid) were studied at the MP2/6-311++G(d,p) level of theory. In the gas phase, neutral L-alanine leads to more stable complexes than the zwitterionic forms while the reverse is true in the aqueous phase. The complexes are formed via two hydrogen bond interactions, which result in a ring-like hydrogen-bonded networks. The nature of H-bonds was characterized in terms of natural bond orbital and quantum theory of atoms in molecule analyses (QTAIM). The H-bonds in the studied complexes were electrostatic in nature; however, in the case of shorter and directional H-bonds and ionic interactions, contributions of covalent character were also non-negligible. Natural energy decomposition analysis of hydrogen-bonded complexes reveals that the charge transfer and electrical components are the largest contributors for the interaction energies of complexes. Natural resonance theory analysis suggests higher resonance weight for charge-assisted interactions of vitamin C---alanine (zwitterionic) complexes, where the total interaction energy is considerably higher than that of neutral alanine.

Quantum Mechanics Approach to Hydration Energies and Structures of Alanine and Dialanine.

A systematic approach to the phenomena related to hydration of biomolecules is reported at the state of the art of electronic-structure methods. Large-scale CCSD(T), MP4-SDQ, MP2, and DFT(M06-2X) calculations for some hydrated complexes of alanine and dialanine (Ala⋅13 H2 O, Ala2 H+ ⋅18 H2 O, and Ala2 ⋅18 H2 O) are compared with experimental data and other elaborate modeling to assess the reliability of a simple bottom-up approach. The inclusion of a minimal number of water molecules for microhydration of the polar groups together with the polarizable continuum model is sufficient to reproduce the relative bulk thermodynamic functions of the considered biomolecules. These quantities depend on the adopted electronic-structure method, which should be chosen with great care. Nevertheless, the computationally feasible MP2 and M06-2X functionals with the aug-cc-pVTZ basis set satisfactorily reproduce values derived by high-level CCSD(T) and MP4-SDQ methods, and thus they are suitable for future developments of more elaborate and hence more biochemically significant peptides.

A non-covalent interaction of Schiff base copper alanine complex with green synthesized reduced graphene oxide for highly selective electrochemical detection of nitrite

A novel and selective nitrite sensor based on non-covalent interaction of Schiff base copper complex [Cu(sal-ala)(phen)] with reduced graphene oxide (RGO) was developed by simple eco-friendly approach.

Chemical deposition of CdS films by an ammonia-free process with amino acids as complexing agents

Highly crystalline CdS films were deposited by an ammonia-free chemical bath deposition process which uses amino acids as complexing agents. All films have shown the hexagonal (wurzite) structure with preferential orientation in the plane (002). As consequence of the difference in the stability between the Cd–glycine and Cd–alanine complexes, CdS films with different thicknesses were obtained. The band gap energy values of the resulting films were at the range of 2.43 to 2.52eV.

Low temperature synthesis of nanocrystalline scandia-stabilized zirconia by aqueous combustion method and its characterizations

Zirconia stabilized with 11 mol% scandia (11ScSZ) has been successfully synthesized by novel alanine-assisted soft chemical aqueous combustion method. The reaction kinetics during combustion synthesis has been studied in detail by analysing thermal behaviour of different metal–alanine complexes. A single phase 11ScSZ powder is achieved at significantly low calcination temperature of 500∘C. Field emission scanning electron micrograph reveals an agglomerated morphology with particle size ranging from 80 to 100 nm. The thermal expansion coefficient is found to be 11.03 × 10−6 ∘C−1 in the temperature range between room temperature and 1000∘C. Optical bandgap of 5.19 eV has been determined using UV–Vis spectroscopy and results are compared with the help of theoretical density of states. The total electrical conductivity of sintered pellet is found to be 7.3 × 10−3 S cm−1 at 700∘C as measured by impedance spectroscopy.

Crystal structure of Alanine‐Copper(II) complex to understand the mechanism of salt induced prebiotic oligomerization of amino acids

Oligomerization of amino acid monomers is the vital step in the formation of longer peptides and functional proteins. In spite of continuing efforts towards solving the puzzle of origin of life, the mystery of chemical evolution remains unsolved. Out of various pathways proposed for the formation of peptides under prebiotic conditions, salt induced peptides synthesis presents the most plausible scenario. In attempts to study mechanism of prebiotic oligomerization of amino acid on primitive earth the current study was aimed to determine the crystal structure of intermediate copper amino acid complex and its supra‐molecular assembly. The Structure of the copper alanine complex obtained from SIPF was studied by x‐ray crystallography. The self‐assembling properties of complex into supra‐molecular nanostructures were studied using Field‐emission electron microscopy (FE‐SEM). Results showed the occurrence of racemization of amino acids. This is the first structural study for copper alanine complex formed from prebiotic peptide synthesis pathway. The aggregational properties of intermediate complex showed the formation of rod like crystals and nanospheres. The findings from our study showed the possible mechanism of prebiotic oligomerization of amino acids on the primitive earth towards formation of longer peptides and functional proteins.

A green chemical method for synthesis of ZnO nanoparticles from solid-state decomposition of Schiff-bases derived from amino acid alanine complexes

As a part of the desire to save the environment via green chemistry practices, we report a novel method to synthesize ZnO nanoparticles from nontoxic and biocompatible chemicals where no pollutant or combustible side product is produced. In this recipe, a binary Zn(II) Schiff-base complex is obtained from alanine where water is used as solvent and a biologically compatible amino acid instead of toxic amines is used as a nitrogen source. The Schiff-base complex is subsequently heat treated to synthesize ZnO particles via a solid-state decomposition process. The effect of post heat treatment temperature (400, 500, and 600°C) on microstructure and defect content of ZnO nanoparticles is investigated. The formation of single phase ZnO particles is confirmed by XRD θ–2θ patterns and FTIR spectra. TEM and SEM micrographs indicate the formation of nanoparticles with a particle size of 50–110nm for different heat treatment temperatures. Combing XRD, FTIR, and PL results, it is revealed that the samples heat treated at intermediate temperatures (500°C) possess the lowest defect concentration and a favorable crystallinity. This study emphasizes on green chemistry and synthesis of nanomaterials through ecofriendly methods to save our planet and its reservoirs for future and next generations.

Photochemical redox reactions of copper(II)-alanine complexes in aqueous solutions.

The photochemical redox reactions of Cu(II)/alanine complexes have been studied in deaerated solutions over an extensive range of pH, Cu(II) concentration, and alanine concentration. Under irradiation, the ligand-to-metal charge transfer results in the reduction of Cu(II) to Cu(I) and the concomitant oxidation of alanine, which produces ammonia and acetaldehyde. Molar absorptivities and quantum yields of photoproducts for Cu(II)/alanine complexes at 313 nm are characterized mainly with the equilibrium Cu(II) speciation where the presence of simultaneously existing Cu(II) species is taken into account. By applying regression analysis, individual Cu(I) quantum yields are determined to be 0.094 ± 0.014 for the 1:1 complex (CuL) and 0.064 ± 0.012 for the 1:2 complex (CuL2). Individual quantum yields of ammonia are 0.055 ± 0.007 for CuL and 0.036 ± 0.005 for CuL2. Individual quantum yields of acetaldehyde are 0.030 ± 0.007 for CuL and 0.024 ± 0.007 for CuL2. CuL always has larger quantum yields than CuL2, which can be attributed to the Cu(II) stabilizing effect of the second ligand. For both CuL and CuL2, the individual quantum yields of Cu(I), ammonia, and acetaldehyde are in the ratio of 1.8:1:0.7. A reaction mechanism for the formation of the observed photoproducts is proposed.

Hydrophobic-Radical Influence on the Structure and Vibrational Spectra of Zwitterionic Glycine and Alanine in the Condensed State

The structure and vibrational spectra of zwitterionic glycine and alanine in aqueous solution and the solid state were calculated in the B3LYP/6-311++G(d,p) approximation. The environment infl uence was taken into account by two methods, i.e., the self-consistent reaction fi eld (SCRF) model and a clear accounting for the effects of hydrogenbonds (complexes with water molecules). The geometric, energetic, and spectral characteristics required to establish that a hydrophobic radical affected the ability of glycine and alanine to form H-bonds were determined. It was found by comparison with experiment that zwitterionic glycine and alanine in the condensed states had to be surrounded with three water molecules, one of which was situated between the N+H3 and COO– ions, in order to calculate their vibrational (IR and Raman) spectra. The formation energies of the alanine complexes with water were 56.47 kcal/ mol and 12.55 kcal/mol greater than those of glycine for formation of a complex with one water molecule situated between the ionized groups and with three water molecules, respectively.

Alanine Water Complexes

Two complexes of alanine with water, alanine-(H2O)n (n = 1,2), have been generated by laser ablation of the amino acid in a supersonic jet containing water vapor and characterized using Fourier transform microwave spectroscopy. In the observed complexes, water molecules bind to the carboxylic group of alanine acting as both proton donors and acceptors. In alanine-H2O, the water molecule establishes two intermolecular hydrogen bonds forming a six-membered cycle, while in alanine-(H2O)2 the two water molecules establish three hydrogen bonds forming an eight-membered ring. In both complexes, the amino acid moiety is in its neutral form and shows the conformation observed to be the most stable for the bare molecule. The microsolvation study of alanine-(H2O)n (n = 1,2) can be taken as a first step toward understanding bulk properties at a microscopic level.

Complex formation of FeIII, CuII, and ZnII with l-3-(3,4-dihydroxyphenyl)alanine in aqueous solutions

The states of the iron(iii), copper(ii), and zinc(ii) complexes with l-3-(3,4-dihydroxyphenyl)alanine in water were studied by spectrophotometry and nuclear magnetic relaxation. The spectral and magnetic relaxation parameters of the l-3-(3,4-dihydroxyphenyl)alanine complexes with iron(iii) ions were determined. The compositions and stability constants of the complexes were found by the mathematical simulation of the obtained data. The conclusions about the formation of a series of homo- and heterobinuclear complexes were made on the basis of an analysis of changes in the optical spectra and values of relaxation efficiency of solutions in systems iron(iii)-l-3-(3,4-dihydroxyphenyl)alanine-MII (MII = CuII, ZnII).