			Home About us Contact

Malachite Green (malachite + green)

Distribution by Scientific Domains

Chemistry	90%

Selected Abstracts

Electrochemical Preparation of Poly(Malachite Green) Film Modified Nafion-Coated Glassy Carbon Electrode and Its Electrocatalytic Behavior Towards NADH, Dopamine and Ascorbic Acid

ELECTROANALYSIS, Issue 14 2007
Shen-Ming Chen
Abstract Poly(malachite green) film modified Nafion-coated glassy carbon electrodes have been prepared by potentiodynamic cycling in malachite green solution. The pH of polymerisation solution has only minor effect on film formation. Electrochemical quartz crystal microbalance (EQCM) was used to monitor the growth of the poly(malachite green) film. Cyclic voltammogram of the poly(malachite green) film shows a redox couple with well-defined peaks. The redox response of the modified electrode was found to be depending on the pH of the contacting solution. The peak potentials were shifted to a less positive region with increasing pH and the dependence of the peak potential was found to be 56,mV per pH unit. The electrocatalytic behavior of poly(malachite green) film modified Nafion-coated glassy carbon electrodes was tested towards oxidation of NADH, dopamine, and ascorbic acid. The oxidation of dopamine and ascorbic acid occurred at less positive potential on poly(malachite green) film compared to bare glassy carbon electrode. In the case of NADH, the overpotential was reduced substantially on modified electrode. Finally, the feasibility of utilizing poly(malachite green) film electrode in analytical estimation of ascorbic acid was demonstrated in flow injection analysis. [source]

Study on Preconcentration of Trace Copper Using Microcrystalline Triphenylmethane Loaded with Malachite Green

CHINESE JOURNAL OF CHEMISTRY, Issue 4 2007
Yong Liang
Abstract The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry (FAAS). Under the optimum conditions, Cu(II) can be totally adsorbed on the surface of microcrystalline triphenylmethane, and completely separated from Pb(II), Cd(II), Co(II), Cr(III), Ni(II), Mn(II), Fe(III) and Al(III) by controlling acidity. The preconcentration factor of this proposed method is 200. The recovery is in a range of 97.5%,105%. The relative standard deviation (RSD) is not beyond 3.0%. The proposed method has been successfully applied to the determination of trace copper in various water samples with satisfactory results. [source]

Electrochemical Preparation of Poly(Malachite Green) Film Modified Nafion-Coated Glassy Carbon Electrode and Its Electrocatalytic Behavior Towards NADH, Dopamine and Ascorbic Acid

Comparison of antifungal therapeutic indices of formalin, malachite green, and potassium permanganate in treating Persian Sturgeon eggs

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2006
Behrooz Abtahi
No abstract is available for this article. [source]

Adduct-forming tendencies of cationic triarylmethane dyes with proteins: Metabolic and toxicological implications

JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2004
Özden Tacal
Abstract The formation of colorless adducts by four cationic triarylmethane dyes (TAM+s), methyl green (MeG+), malachite green (MG+), pararosaniline (PR+), and crystal violet (CV+) was studied spectrophotometrically at 25°C, in 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) buffer (pH 8), by monitoring the loss in TAM+ color in the absence and presence of human serum proteins as potential addends. Unfractionated serum caused a rapid bleaching of MeG+ and MG+, while PR+ and CV+ were unaffected. Sephacryl S200 HR chromatographic screening of the serum revealed two composite peaks of MeG+ -bleaching activity. The major peak (Mr range, 40,000,130,000) overlapped with and extended on either side of the albumin peak. The minor peak corresponding to ca. 10% of the total MeG+ -bleaching capacity had Mr > 230,000. MG+ -bleaching activity dominated the entire chromatographic profile and implicated a multitude of minority proteins with a high capacity to form colorless MG adducts. It is concluded that highly electrophilic TAM+s such as MeG+ and MG+ must be quantitatively trapped in the form of dye,protein adducts in biological fluids and that the primary in vivo effects (e.g. toxicity) of such dyes most likely arise from ligand-type effects on multiple protein targets. Mechanisms that call for unmodified TAM+ structure (radical-mediated redox changes, DNA intercalation) may be more relevant to the in vivo impact of dyes such as PR+ and CV+ that have a lower tendency to form adducts. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:253,256, 2004 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20034 [source]

Engineered 5S ribosomal RNAs displaying aptamers recognizing vascular endothelial growth factor and malachite green

JOURNAL OF MOLECULAR RECOGNITION, Issue 2 2009
Xing Zhang
Abstract In previous work, Vibrio proteolyticus 5S rRNA was shown to stabilize 13,50 nucleotide "guest" RNA sequences for expression in Escherichia coli. The expressed chimeric RNAs accumulated to high levels in E. coli without being incorporated into ribosomes and without obvious effects on the host cells. In this work, we inserted sequences encoding known aptamers recognizing a protein and an organic dye into the 5S rRNA carrier and showed that aptamer function is preserved in the chimeras. A surface plasmon resonance competitive binding assay demonstrated that a vascular endothelial growth factor (VEGF) aptamer/5S rRNA chimera produced in vitro by transcriptional runoff could compete with a DNA aptamer for VEGF, implying binding of the growth factor by the VEGF "ribosomal RNA aptamer." Separately, a 5S rRNA chimera displaying an aptamer known to increase the fluorescence of malachite green (MG) also enhanced MG fluorescence. Closely related control rRNA molecules showed neither activity. The MG aptamer/5S rRNA chimera, like the original MG aptamer, also increased the fluorescence of other triphenyl methane (TPM) dyes such as crystal violet, methyl violet, and brilliant green, although less effectively than with MG. These results indicate that the molecular recognition properties of aptamers are not lost when they are expressed in the context of a stable 5S rRNA carrier. Inclusion of the aptamer in a carrier may facilitate production of large quantities of RNA aptamers, and may open an approach to screening aptamer libraries in vivo. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Equilibrium and kinetic study for the removal of malachite green using activated carbon prepared from Borassus flabellofer male flower

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2010
P. E. Jagadeesh Babu
Abstract Activated carbon was prepared from dried Borassus flabellofer male flower and batch adsorption experiments were conducted to study its potential to remove malachite green (MG) dye. The process was further optimized by studying the operating variables like initial pH of the stock solution, activation temperature, initial dye concentration, adsorbent loading and contact time. The optimized pH and activation temperatures were found to be 7.55 and 450 °C respectively, where further analysis was made using these optimal variables. Linear, Freundlich and Langmuir isotherms were studied and it was found that the Langmuir isotherms have the highest correlation coefficients compared to the others. Further, the sorption kinetics were analysed using pseudo-first-order and pseudo-second-order kinetic models. The data showed that the second-order equation was the more appropriate, which indicate that the intra-particle diffusion is the rate limiting factor. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Discrimination of G-Quadruplexes from Duplex and Single-Stranded DNAs with Fluorescence and Energy-Transfer Fluorescence Spectra of Crystal Violet

CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2009
De-Ming Kong Dr.
Abstract G-rich nucleic acid sequences with the potential to form G-quadruplex structures are common in biologically important regions. Most of these sequences are present with their complementary strands, so the development of a sensitive biosensor to distinguish G-quadruplex and duplex structures and to determine the competitive ability of quadruplex to duplex structures has received a great deal of attention. In this work, the interactions between two triphenylmethane dyes (malachite green (MG) and crystal violet (CV)) and G-quadruplex, duplex, or single-stranded DNAs were studied by fluorescence spectroscopy and energy-transfer fluorescence spectroscopy. Good discrimination between quadruplexes and duplex or single-stranded DNAs can be achieved by using the fluorescence spectrum of CV or the energy-transfer fluorescence spectra of CV and MG. In addition, by using energy-transfer fluorescence titrations of CV with G-quadruplexes, the binding-stoichiometry ratios of CV to G-quadruplexes can be determined. By using the fluorescence titrations of G-quadruplex,CV complexes with C-rich complementary strands, the fraction of G-rich oligonucleotide that engages in G-quadruplex structures in the presence of the complementary sequence can be measured. This study may provide a simple method for discrimination between quadruplexes and duplex or single-stranded DNAs and for measuring G-quadruplex percentages in the presence of the complementary C-rich sequences. [source]