Presence Of 3-mercaptopropionic Acid Research Articles

Chromatographic and spectrophometric studies of vanadate (+V) reduction by 3–mercaptopropionic acid

The reduction of vanadate (+V) in the presence of 3-mercaptopropionic acid was studied using a chromatographic method for the determination of vanadate (+V) versus vanadyl (+IV) species. Ion chromatography was combined with spectrophotometric investigation of the absorption properties of the solution. The chromatographic method for the separation of vanadate (+V) and vanadyl (+IV) was carried out with an anion exchange column. In the initial reaction mixture containing vanadate (+V) and 3-mercaptopropionic acid, ethylenediaminetetraacetic acid – EDTA was added in an excessive amount relative to the concentration of reactants in the solution. After the ligand exchange reaction, the added EDTA terminates the reduction, allowing redox speciation in the solutions. A strong pH dependence of the reduction rates in the investigated solution was observed. The vanadate reduction seems to proceed in 2 steps: 1) formation of the intermediate vanadate (+V)-thioester; 2) reduction reaction and formation of the vanadyl (+IV)-thiol complex. The obtained results strongly suggest that the reaction of vanadate (+V)-thioester formation is proton catalyzed. It was observed that the overall reduction rates are pH dependent due to the complex vanadate (+V) solution speciation and changes in the ionic form of 3-mercaptopropionic acid.

Photoluminescence investigation of MPA–ZnS QDs interaction with selenite ion

The interaction between water-soluble zinc sulfide quantum dots (ZnS QDs) and selenite ion was investigated by photoluminescence method. The water-soluble ZnS QDs were synthesized using a simple and fast procedure based on the co-precipitation of nanoparticles in an aqueous solution in the presence of 3-mercaptopropionic acid (MPA), as the capping agent. Fluorescence intensity for MPA–ZnS QDs, with a strong fluorescent emission at about 430 nm, decreased in the presence of selenite. The influence of the effective parameters including pH and temperature was investigated. The results showed that under the optimum conditions, the fluorescence intensity change of QDs was linearly proportional to the selenite concentration in the range 4.0 × 10−5–7.2 × 10−4 mol L−1. Moreover, the quenching mechanism was discussed to be a static quenching procedure.

Synthesis, characterization and biomolecular interactions of Cu(II) and Ni(II) complexes of acyclic Schiff base ligand

Mononuclear copper(II) (1) and nickel(II) complexes (2) of acyclic Schiff base ligand, N,N′-bis(2-hydroxy-1-naphthyl)-1,4-bis(3-iminopropyl) piperazine (L) were synthesized and characterized. The molecular structure of the ligand was confirmed using single crystal X-ray diffraction analysis. The complexes displayed good binding abilities to bovine serum albumin protein (BSA). The binding interactions of complexes 1 and 2 with calf thymus DNA (CT-DNA) was investigated by absorption, fluorescence, circular dichroism spectral analysis and molecular docking studies. Complex 1 showed greater interaction with DNA than nickel(II) complex 2. The cleavage studies with pBR322 DNA showed efficient oxidative cleavage in the presence of 3-mercaptopropionicacid (MPA) and for hydrogen peroxide for complexes 1 and 2 respectively.

Cobalt(III) complexes as potential anticancer agents: Physicochemical, structural, cytotoxic activity and DNA/protein interactions

Cobalt(III) complexes (1–3) such as [Co(acac)(bpy)(N3)2·H2O] 1, [Co(acac)(en)(N3)2] 2, and [Co(acac)(2-pic)(N3)2] 3 (where, acac=acetylacetone, bpy=2.2′-bipyridine, en=ethylenediamine, 2-pic=2-picolylamine and NaN3=sodium azide) were synthesized and characterized. The structure of complexes (1–3) has been determined by single crystal X-ray diffraction studies and the configuration around cobalt(III) ion was distorted octahedral coordination geometry. Density functional theory calculations were performed to examine the molecular geometry and frontier molecular orbital properties of complexes (1–3). DNA binding properties of the cobalt(III) complexes with calf thymus DNA (CT-DNA) were investigated by UV–visible absorption, fluorescence, circular dichroism spectroscopy and viscosity measurements. The docking studies showed the preferred orientation of sterically acceptable Co(III) complexes (1, 2) inside the DNA through the mode of intercalation, whereas complex 3 exhibited minor groove binding modes. The intrinsic binding constants Kb of complexes (1–3) with CT-DNA were in the following order 1>3>2. Complexes (1–3) exhibit a good binding propensity to bovine serum albumin (BSA) and gel electrophoresis assay demonstrated that the complexes (1–3) promote the cleavage of the pBR322 DNA in the presence of 3-mercaptopropionic acid (MPA) and cleavage process was found to proceed by singlet oxygen cleavage mechanism. Further, the in vitro cytotoxicity studies of complexes (1–3) were tested on human breast cancer cell line (MCF-7).

Exploring the photochemosensitivity by novel cysteine-based mixed ligand complexes

A new series of cysteine-based metal(II) complexes with 2,2′-bipyridine or 1,10-phenanthroline as co-ligand have been prepared and characterized. Their DNA binding and cleavage properties have been studied. The analytical and spectroscopic data of complexes 1–18 reveal that the complexes adopt an octahedral geometry around the central metal ion in which the cysteine is coordinated through NS and NN atoms, respectively. Spectroscopic titration and viscosity measurements reveal that the complexes bind to DNA through an intercalative mode. Electrophoresis measurements exhibit that they cleave pBR322 DNA efficiently in the presence of 3-mercaptopropionic acid (MPA), probably via hydrolytic mechanism with the involvement of •OH. The in vitro anticancer activities indicate that the Cu(II) complexes are active against four selected human tumor cell lines. Furthermore, it is remarkable that all the complexes exhibit significant photocytotoxicity against human breast cancer cell lines (MCF-7) with a potency more than the widely used drugs photofrin and cisplatin indicating that they have the potential to act as effective anticancer drugs in a dose-dependent manner.

ChemInform Abstract: A Facile Route to Aqueous Ag:ZnCdS and Ag:ZnCdSeS Quantum Dots: Pure Emission Color Tunable over Entire Visible Spectrum.

AbstractAqueous Ag:ZnCdS quantum dots (QDs) are prepared based on a co‐nucleation doping strategy using aqueous solutions of Cd(OAc)2, Zn(OAc)2 (in presence of mercaptopropionic acid; Cd:Zn molar ratio of 1:1), and AgNO3 at pH 7 to which a reactive S (and Se) powder precursor (hydrothermal S (Se) solution in presence of NaBH4) is given (autoclave, 180 °C, 2 h).

Synthesis, Characterization and Evaluation of the Cytotoxicity of Ni-Doped Zn(Se,S) Quantum Dots

Quantum dots (QDs) are semiconductor nanocrystals with desirable optical properties for biological applications, such as bioimaging and drug delivery. However, the potential toxicity of these nanostructures in biological systems limits their application. The present work is focused on the synthesis, characterization, and evaluation of the toxicity of water-stable Ni-doped Zn(Se,S) QDs. Also, the study of nondoped nanostructures was included for comparison purposes. Ni-doped nanostructures were produced from zinc chloride and selenide aqueous solutions in presence of 3-mercaptopropionic acid and Ni molar concentration of 0.001 M. In order to evaluate the potential cytoxicity of these doped nanostructures, human pancreatic carcinoma cells (PANC-1) were used as model. The cell viability was monitored in presence of Ni-doped Zn(Se,S) QDs at concentrations ranging from 0 μg/mL to 500 μg/mL and light excited Ni-doped Zn(Se,S) nanostructures were evaluated at 50 μg/mL. Results suggested that Ni-doped Zn(Se,S) nanostructures were completely safe to PANC-1 when concentrations from 0 μg/mL to 500 μg/mL were used, whereas non-doped nanostructures evidenced toxicity at concentrations higher than 200 μg/mL. Also, Ni-doped Zn(Se,S) QDs under light excitation do not evidence toxicity to PANC-1. These findings suggest strongly that Zn(Se,S) nanostructures doped with nickel could be used in a safe manner in light-driving biological applications and drug delivery.

Structural, Compositional, and Biological Characterization of Fe3O4 Nanoparticles Synthesized by Hydrothermal Method

In this research, magnetite nanoparticles (MNPs) have been prepared at 200°C for 2 h by hydrothermal method in presence of 3-mercaptopropionic acid (3-MPA) as a capping agent. Morphological and structural studies carried out by scanning electron microscope (SEM), that results show nanoparticles have been constructed in cubic shape with medium size about 20–30 nm, can produce clusters in 50–200 nm. X-ray diffraction results show that MNPs are in cubic crystal phase. Investigation of thermochemical properties and changing state of Fe2O3 in higher temperature, carried out with analysis of STA (DTA/TGA) that shows MNPs have changed the phase in 280°C and converted to hematite (α-Fe2O3) with rhombohedral crystal phase. Investigation of anticancer properties of nanoparticles show that after 72 h excellent anti-tumor activity against two kinds of cancer cells that are LNCAP (human prostate carcinoma) cells and HeLa (human cervix carcinoma) cells. The results are completely new and provide new views for using of the mentioned compounds in chemotherapy. Antibacterial properties of MNPs also have been studied and good results obtained.

Synthesis, structural, electrochemical, DNA interaction, antimicrobial and molecular docking studies on dimeric copper(II) complexes involving some potential bidentate ligands

The dimeric copper(II) complexes [Cu2(bpy)2(L1)2(ClO4)2] (1), [Cu2(biim)2(L1)2(ClO4)2] (2), [Cu2(bpy)2(L2)2](ClO4)2 (3) and [Cu2(biim)2(L2)2](ClO4)2 (4) (where bpy=2,2′-bipyridine, biim=2,2′-biimidazole, L1=5-methylsalicylaldehyde and L2=5-bromosalicylic acid) have been synthesized and characterized by IR, UV–Vis, ESR and ESI-mass spectroscopy. The single crystal X-ray diffraction study of complexes 1 and 3 showed that the complexes crystallize in triclinic crystal system with the P1¯ space group. All the complexes showed one quasi-reversible redox wave in the cathodic region (E1pc=−0.83 to −0.90V), assignable to the Cu(II)/Cu(I) redox couple. The binding interaction of the complexes with calf thymus DNA (ctDNA) was investigated by absorption, fluorescence, circular dichroism spectral studies and molecular docking techniques. The copper(II) complexes showed good binding affinity to ctDNA and the intrinsic binding constants obtained from UV–Vis spectroscopic studies are 1.16×105, 3.19×105, 1.82×105 and 3.66×105M−1 for complexes 1–4, respectively. The apparent binding constant obtained from fluorescence spectroscopic studies are 1.37×105, 3.33×105, 2.2×105 and 4.7×105M−1 for the complexes 1–4, respectively. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid (MPA) and the cleavage process was found to proceed by a hydroxyl radical mechanism. The ligands and their Cu(II) complexes were screened for antimicrobial activities and the results indicated that the complexes exhibit significant antimicrobial activity compared to the free ligands.

Aqueous synthesis of highly luminescent CdSe quantum dots with narrow spectra using hydrazine hydrate reduction selenium

Highly luminescent CdSe quantum dots (QDs) with narrow spectra were synthesised by the reaction of CdCl2·2.5H2O, Se and hydrazine hydrate (N2H4·H2O), respectively, in water and in the presence of 3-mercaptopropionic acid as the stabiliser. The effects of the experimental conditions, including the refluxing time and the selenium to cadmium molar ratio, on the luminescent properties of the obtained QDs have been investigated. Furthermore, the obtained QDs were characterised by UV–vis absorption spectra, photoluminescence (PL) spectra, X-ray powder diffraction and transmission electron microscopy, respectively. The results showed that the proposed method led to the formation of the cubic CdSe QDs with a narrow fluorescence full-width at half-maximum (47 nm) and a high PL quantum yield (up to 16%), respectively.

One-pot synthesis and characterization of chalcopyrite CuInS2 nanoparticles

We synthesized tetragonal chalcopyrite CuInS2 (CIS) nanoparticles from molecular single source precursors, (Ph3P)2Cu-(μ-SEt)2In(SEt)2, by a one-pot reaction in the presence of 3-mercaptopropionic acid at reaction times of 3 hours or less with high yields.

Synthesis of mononuclear copper(II) complexes of acyclic Schiff’s base ligands: Spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity

The mononuclear copper(II) complexes (1&2) of ligands L1 [N,N′-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L2 [N,N′-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L1 and L2 crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (−0.77 to −0.85V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands.

μ-Oxamido binuclear copper (II) complexes: Synthesis, crystal structure, DNA interaction and antibacterial studies

Four binuclear copper (II) complexes [Cu(oxpn)Cu(B)]2+ (2–5) bridged by N, N′-bis[3-(methylamino) propyl] oxamide (oxpn), where, B is N, N-donor heterocyclic bases (viz. 2,2′-bipyridine (bpy, 2), 1,10-phenathroline (phen, 3), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 4) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 5) are synthesized, characterized by different spectroscopic and single crystal X-ray data technique. The phen (3) and dpq (4) complexes were structurally characterized by X-ray data analysis. Their DNA binding, oxidative cleavage and antibactirial activities were studied. The dpq (4) and dppz (5) complexes are avid binders to the Calf thymus DNA (CT-DNA). The phen (3), dpq (4) and dppz (5) complexes show efficient oxidative cleavage of supercoiled DNA (SC DNA) through hydroxyl radical (OH) pathway in the presence of Mercaptopropionic acid (MPA).

Microstructural and Potential Dependence Studies of Urease-Immobilized Gold Nanoparticles–Polypyrrole Composite Film for Urea Detection

Gold nanoparticle-polypyrrole nanocomposite film was electrochemically deposited in a single-step polymerization of pyrrole in the presence of 3-mercaptopropionic acid (MPA)-capped gold nanoparticles (GNPs) and p-toluenesulfonic acid (pTSA) on the surface of an indium tin oxide (ITO)-coated glass plate. The carboxyl functional groups surrounding the GNPs within the polymer matrix were utilized for the immobilization of urease enzyme through carbodiimide coupling reaction for the construction of a Urs/GNP(MPA)-PPy/ITO-glass bioelectrode for urea detection in Tris-HCl buffer. The resulting bioelectrode film was characterized by atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), contact angle measurement, Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The potentiometric response of the bioelectrode made of polymer nanocomposite films of two different thicknesses prepared at 100 and 250 mC cm(-2) charge densities, respectively, was studied towards the urea concentration in Tris-HCl buffer (pH7.4). The thin polymer nanocomposite film-based bioelectrode prepared at 100 mC cm(-2) charge density exhibited a comparatively good potentiometric response than a thick 250 mC cm(-2) charge density film with a linear range of urea detection from 0.01 to 10mM with a sensitivity of 29.7mV per decade.

Preparation and characterization of a new halo chromate nanoparticle: Triphenylphosphonium trifluoroiodochromate (III)[P(C6H5)3H]+[CrF3I

A new mixed halo chromate nanoparticle compound was synthesised and characterized. Triphenylphosphonium trifluoroiodochromate (III)[P(C6H5)3H]+[CrF3I]- nanoparticle was synthesized by using triphenylphosphonium iodide reaction with CrF3, in the presence of 3-mercaptopropionic acid. This method is a simple and direct method. The product was characterized by spectroscopic and analytical methods such as 31P-NMR, FT-IR, XRD, SEM. Theoretical calculations were used for the structural optimization of this compound. The structure of compound has been calculated and optimized by the density functional theory (DFT) based method at B3LYP/6-311G levels of theory, using the Gaussian 98 package of programs. The comparison between theory and experiment is made. On the base of application of scanning electron microscopy (SEM) is showed about 54 nm particle sizes.

Determination of gabapentin in human plasma using simultaneous cloud point extraction and precolumn derivatization by HPLC

A simultaneous cloud point extraction and precolumn derivatization method was developed for the determination of gabapentin in human plasma samples. o-Phthaldialdehyde in the presence of 3-mercaptopropionic acid and Triton X-100 were used as derivatization reagents and extraction solvent, respectively. Some parameters with an effect on the extraction, such as the concentration of Triton X-100, incubation time, equilibration temperature, ionic strength, and centrifuging time, were studied and optimized. Under the optimum conditions, average recovery of gabapentin was in the range of 94.5–98.7 %. The calibration curve was linear in the range of 0.01–50 μg/cm3. The limits of detection and quantification were 0.003 and 0.01 μg/cm3, respectively. The relative standard deviations were in the range of 0.9–5.2 %. The obtained results show that simultaneous derivatization and cloud point extraction combined with high-performance liquid chromatography is a sensitive and simple method for the determination of gabapentin in plasma samples.

DNA Binding and Oxidative Cleavage Activity of Ternary (α-Lipoic Acid) Copper(II) Complex of Heterocyclic Base

Ternary copper(II) complex [Cu(α-lipo)(phen)(Cl)](NO3) where α-lipo = α-lipoic acid, phen is N, N-donor heterocyclic base, 1,10-phenanthroline was synthesized, characterized, and its DNA binding and cleavage activity were studied. Binding interactions of the complex with calf thymus (CT) DNA has been investigated by emission, viscosity, and DNA melting studies. The complex shows efficient oxidative cleavage of SC-DNA in the presence of 3-mercaptopropionic acid involving hydroxyl radical species, and results of control experiments exhibit the inhibition of DNA cleavage in the presence of hydroxyl radical scavengers, viz. DMSO and KI.

Oxidative DNA cleavage, cytotoxicity and antimicrobial studies of l-ornithine copper (II) complexes

New ternary copper (II) complexes, [Cu(l-orn)(B)(Cl)](Cl·2H2O) (1–2) where l-orn is l-ornithine, B is an N,N-donor heterocyclic base, viz. 2,2′-bipyridine (bpy, 1) and 1,10-phenanthroline (phen, 2), were synthesized and characterized by various spectroscopic techniques. Complex 2 is characterized by the X-ray single crystallographic method. The complex shows a distorted square-pyramidal (4+1) CuN3OCl coordination sphere. Binding interactions of the complexes with calf thymus DNA (CT-DNA) were investigated by UV–Vis absorption titration, ethidium bromide displacement assay, viscometric titration experiment and DNA melting studies. Complex 2 shows appreciable chemical nuclease activity in the presence of 3-mercaptopropionic acid (MPA). The complexes were subjected to in vitro cytotoxicity studies against carcinomic human alveolar basal epithelial cells (A-549) and human epithelial (HEp-2) cells. The IC50 values of 1 and 2 are less than that of cisplatin against HEp-2 cell lines. MIC values for 1 against the bacterial strains Streptococcus mutans and Pseudomonas aeruginosa are 0.5mM.

A copper(II) complex of the Schiff base from l-valine and 2-hydroxy-1-naphthalidene plus 1,10-phenanthroline: synthesis, crystal structure, and DNA interaction

A new Cu(II) complex, [Cu(naph-val)phen] (naph-val = Schiff base derived from 2-hydroxy-1-naphthaldehyde and l-valine, phen = 1,10-phenanthroline), has been synthesized and characterized by physicochemical methods. The crystal structure of the complex showed that there are four independent molecular structures in the crystallographic asymmetric unit, and each of them shows a distorted square-pyramidal CuN3O2 coordination geometry. In the crystal, the π − π stacking and intermolecular hydrogen bonds form a 2D network. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by spectroscopic methods, as well as viscosity and thermal denaturation measurements. The results indicate that the Cu(II) complex binds to CT-DNA in an intercalative mode. The cleavage reaction on pBR322 plasmid DNA has been investigated by agarose gel electrophoresis in the absence and presence of mercaptopropionic acid. The Cu(II) complex exhibits an efficient DNA cleavage activity.

Preparation of rhenium nanoparticles via pulsed-laser decomposition and catalytic studies

Rhenium (Re) nanoparticles have been synthesized by pulsed-laser decomposition of ammonium perrhenate (NH4ReO4) or dirhenium decacarbonyl (Re2(CO)10) in the presence of 3-mercaptopropionic acid (MPA) as capping agent, in both aqueous and organic media. Preliminary studies showed that the MPA-capped Re nanoparticles are capable of catalyzing the isomerization of 10-undecen-1-ol to internal alkenols via long chain migration of the CC double bond at ca. 200°C. A one-pot synthesis of graphite-coated Re nanoparticles has also been achieved by pulsed-laser decomposition of Re2(CO)10, due to photo-induced catalytic graphitization of the phenyl groups of PPh3 on the surface of rhenium nanoparticles.