carbocyanines and quinaldine-blue

Residual Dipolar Couplings (RDCs) are integral to the refinement of membrane protein structures by NMR since they accurately define the orientation of helices and other structural units. Only a small set of liquid crystals used for RDC measurements are compatible with the detergents needed in membrane protein studies. The available detergent-compatible liquid crystals are negatively charged, thus offering effectively only one of five orthogonal components of the alignment Saupe matrix. In this communication, we present a robust liquid crystalline medium that is positively charged, pinacyanol acetate (PNA), for the determination of orthogonal sets of RDCs in membrane proteins. This new medium promises to enhance the accuracy of membrane protein structures and the measurement of dynamics based on RDCs.

Topics: Carbocyanines; Hydrogen-Ion Concentration; Liquid Crystals; Magnetic Resonance Spectroscopy; Membrane Proteins; Models, Molecular; Protein Structure, Secondary

The synthesis of a geometrically constrained and near-planar hexacyclic acridinium cyanine dye 9 is reported. When compared to its unlocked and non-fluorescent monomethine cyanine dye analogue 3, this photostable dye emits in the green area of the spectrum with a remarkable quantum yield close to unity in organic solvents and above 0.5 in water. A detailed steady-state and time-resolved spectroscopic study revealed that dye 9 forms emissive aggregates in water, which are responsible for a red-shifted and broadened emission band and longer emission lifetime, τ≈33 compared to 6.5-7.0 ns for the monomeric dye. Dye 9 also binds strongly to DNA (both duplex and quadruplex) in its monomeric form and is very efficiently taken up by cells, in which it accumulates primarily into the nucleus.

Topics: Acridines; Carbocyanines; DNA; Fluorescent Dyes; Light; Molecular Structure; Solvents; Water

In this work we analyze how nuclear coherences modulate diagonal and off-diagonal peaks in two-dimensional electronic spectroscopy. 2D electronic spectra of pinacyanol chloride are measured with 8 fs pulses, which allows coherent excitation of the 1300 cm(-1) vibrational mode. The 2D spectrum reveals both diagonal and off-diagonal peaks related to the vibrational mode. On early time scales, up to 30 fs, coherent dynamics give rise to oscillations in the amplitudes, positions, and shapes of the peaks in the 2D spectrum. We find an anticorrelation between the amplitude and the diagonal width of the two diagonal peaks. The measured data are reproduced with a model incorporating a high frequency mode coupled to an electronic two-level-system. Our results show that these anticorrelated oscillations occur for vibrational wavepackets and not exclusively for electronic coherences as has been assumed previously.

Topics: Carbocyanines; Electrons; Quantum Theory; Time Factors; Vibration

The interactions of Acridine Orange with Sodium Alginate and Pinacyanol Chloride with Heparin have been investigated by spectrophotometric method. The polymers induce metachromasy in the dye as evidenced from the considerable blue shift in the absorption maxima of the corresponding dyes. The interaction constant and thermodynamic parameters of polymer-dye interactions have been determined. The effect of additives such as alcohols, and urea on the reversal of metachromasy has been studied. The data has been used to determine the stability of the metachromatic complex and the nature of binding. The thermodynamic parameters of interaction revealed that binding between Acridine Orange and Sodium Alginate involved only electrostatic forces while that between Pinacyanol Chloride involved both electrostatic and hydrophobic forces. The reversal studies using surfactants indicated the involvement of both electrostatic and hydrophobic forces in binding. Based on the results it can be concluded that Pinacyanol Chloride is more effective inducing metachromasy than Acridine Orange.

Topics: Acridine Orange; Alcohols; Alginates; Anions; Anticoagulants; Carbocyanines; Cations; Electrolytes; Fluorescent Dyes; Glucuronic Acid; Heparin; Hexuronic Acids; Polymers; Static Electricity; Thermodynamics; Urea

Liposomes incorporating sodium deoxycholate (NaDC) were prepared by the method of reverse phase evaporation and used for drug delivery by the oral route. Hexamethylmelamine (HMM), an anti-tumor agent, was chosen as a model drug and encapsulated into liposomes incorporating NaDC (NaDC-Lip). Several properties of NaDC-Lip containing HMM (HMM NaDC-Lip), such as particle size, entrapment efficiency, pinacyanol chloride (PIN) spectral characteristics with various molar ratio of NaDC/PC, as well as the vesicle stability measurements with calcein were evaluated. In vivo, the area under the plasma concentration-time curve obtained from the pharmacokinetics study of HMM NaDC-Lip was found to be approximately 9.76- and 1.21-fold higher than that of HMM solution and HMM Lip, respectively, indicating that NaDC-Lip can be used as a potential carrier for oral drug administration.

Topics: Administration, Oral; Altretamine; Animals; Antineoplastic Agents, Alkylating; Carbocyanines; Cholesterol; Chromatography, High Pressure Liquid; Deoxycholic Acid; Drug Carriers; Drug Compounding; Drug Stability; Female; Fluoresceins; Lipids; Liposomes; Particle Size; Rats; Rats, Wistar; Spectrophotometry, Ultraviolet

Capsular polysaccharides (SPS) are an integral component of gram-negative bacteria, and also have potential use as vaccine. In this paper, interactions of SPS isolated from Klebsiella strains K20 and K51 with cationic dyes pinacyanol chloride (PCYN) and acridine orange (AO) were studied by absorbance and fluorescence measurements. Both the polysaccharides having glucuronic acid as the potential anionic site induced strong metachromasy (blue shift approximately 100 nm) in the PCYN. The spectral changes were studied at different polymer/dye molar ratios (P/D = 0-40). A complete reversal of metachromasy was observed upon addition of co-solvents, suggesting the breakaway of dye molecules from the biopolymer matrix. Binding constant, changes in free energy, enthalpy and entropy of the dye polymer complex were also computed from the spectral data at different temperatures to reveal the nature of the interaction. Quenching of fluorescence of AO by the polymers and the incorporated mechanisms were also explored.

Topics: Absorption; Acridine Orange; Carbocyanines; Coloring Agents; Ethanol; Klebsiella; Polysaccharides, Bacterial; Spectrum Analysis; Temperature; Thermodynamics

The interaction between pinacyanol chloride and sodium alginate or guluronate-rich alginate is found to effect profound changes in the visible absorbance and circular dichroism spectra. Two different types of aggregates are observed depending on the relative dye/alginate concentrations. With a dye/alginate ratio at 1:1, a complex is deduced based on an analysis of Job's method and conductometric titrations. Another complex forms at 1:10 dye/alginate ratio and only in the presence of alginate or guluronate-rich alginate. The two aggregates are in dynamic equilibrium according to the presence of isosbestic points in the visible spectra. The effects of pH and divalent cations on the spectra are studied. The 1:10 complex is damaged by addition of hydrochloric acid and divalent cations; however, at low concentration of these agents the spectra indicate conversion of the complex into the 1:1 aggregate. Models for the two complexes are proposed taking into account the preference of guluronate binding sites for chelating ions.

Topics: Alginates; Carbocyanines; Carbohydrate Conformation; Carbohydrate Sequence; Cations, Divalent; Circular Dichroism; Eukaryota; Hexuronic Acids; Hydrogen-Ion Concentration; Molecular Sequence Data; Spectrophotometry, Ultraviolet

Interaction of pinacyanol chloride (PIN) with pure and binary mixtures of cetyltrimethylammonium bromide (CTAB) and sodium deoxycholate (NaDC) was spectroscopically studied. Interaction of PIN with pure NaDC produced a blue shifted metachromatic band (at approximately 502 nm), which gradually shifted to higher wavelength region as the concentration of NaDC increased in the pre-micellar stage. For CTAB only intensity of both the bands increased without any shift. Mixed surfactant systems behaved differently than the pure components. Absorbance of monomeric band with a slight red-shift, and a simultaneous decrease in the absorbance of dimeric band of PIN, were observed for all the combinations in the post-micellar region. PIN-micelle binding constant (K(b)) for pure as well as mixed was determined from spectral data using Benesi-Hildebrand equation. Using the idea of Regular Solution Theory, micellar aggregates were assumed to be predominant than other aggregated state, like vesicles. Aggregation number was determined by fluorescence quenching method. Spectral analyses were also done to evaluate CMC values. Rubinigh's model for Regular Solution Theory was employed to evaluate the interaction parameters and micellar composition. Strong synergistic interaction between the oppositely charged surfactants was noted. Bulkier nature of NaDC lowered down its access in mixed micellar system.

Topics: Absorption; Carbocyanines; Kinetics; Micelles; Spectrum Analysis; Surface-Active Agents; Water

Exceptionally high peroxidase-like and catalase-like activities of iron(III)-TAML activators of H 2O 2 ( 1: Tetra-Amidato-Macrocyclic-Ligand Fe (III) complexes [ F e{1,2-X 2C 6H 2-4,5-( NCOCMe 2 NCO) 2CR 2}(OH 2)] (-)) are reported from pH 6-12.4 and 25-45 degrees C. Oxidation of the cyclometalated 2-phenylpyridine organometallic complex, [Ru (II)( o-C 6H 4py)(phen) 2]PF 6 ( 2) or "ruthenium dye", occurs via the equation [ Ru II ] + 1/2 H 2 O 2 + H +-->(Fe III - TAML) [ Ru III ] + H 2 O, following a simple rate law rate = k obs (per)[ 1][H 2O 2], that is, the rate is independent of the concentration of 2 at all pHs and temperatures studied. The kinetics of the catalase-like activity (H 2 O 2 -->(Fe III - TAML) H 2 O + 1/2 O 2) obeys a similar rate law: rate = k obs (cat)[ 1][H 2O 2]). The rate constants, k obs (per) and k obs (cat), are strongly and similarly pH dependent, with a maximum around pH 10. Both bell-shaped pH profiles are quantitatively accounted for in terms of a common mechanism based on the known speciation of 1 and H 2O 2 in this pH range. Complexes 1 exist as axial diaqua species [FeL(H 2O) 2] (-) ( 1 aqua) which are deprotonated to afford [FeL(OH)(H 2O)] (2-) ( 1 OH) at pH 9-10. The pathways 1 aqua + H 2O 2 ( k 1), 1 OH + H 2O 2 ( k 2), and 1 OH + HO 2 (-) ( k 4) afford one or more oxidized Fe-TAML species that further rapidly oxidize the dye (peroxidase-like activity) or a second H 2O 2 molecule (catalase-like activity). This mechanism is supported by the observations that (i) the catalase-like activity of 1 is controllably retarded by addition of reducing agents into solution and (ii) second order kinetics in H 2O 2 has been observed when the rate of O 2 evolution was monitored in the presence of added reducing agents. The performances of the 1 complexes in catalyzing H 2O 2 oxidations are shown to compare favorably with the peroxidases further establishing Fe (III)-TAML activators as miniaturized enzyme replicas with the potential to greatly expand the technological utility of hydrogen peroxide.

Topics: Carbocyanines; Catalase; Ferric Compounds; Hydrogen Peroxide; Hydrogen-Ion Concentration; Iron Compounds; Kinetics; Macrocyclic Compounds; Metalloporphyrins; Oxidation-Reduction; Peroxidase; Ruthenium

Pinacyanol (PIN), as other cyanine dyes, has demonstrated a unique ability to form associates such as dimers, and H- and J-aggregates. This association is strongly favoured in water, and even at low dye concentrations, dimers and superior order aggregates are present. As a consequence, the determination of the dimerization constant involves sometimes a significant error when these aggregates are neglected. As an increase in temperature shifts the equilibrium among the different species towards the lowest order aggregates, we have obtained the spectra of PIN at several temperatures. By extrapolating some spectral characteristics at high temperatures, a spectrum of the dimer without any contribution of other aggregates was obtained. From this spectrum and that of the monomer, the dimerization constant was calculated, as well as the Gibbs energy change associated to the reaction. The enthalpy and entropy changes of the dimerization were determined from the dependence of the dimerization constants on the temperature. From these results it can be inferred that the driving force of the dimerization is of enthalpic origin.

Topics: Carbocyanines; Coloring Agents; Dimerization; Solutions; Spectrophotometry; Thermodynamics

The binding of pinacyanol (PIN), a cationic cyanine dye, to beta-amyloid fibrils (Abeta), which are associated with Alzheimer disease, was quantified by absorption spectrophotometry to measure the concentration of PIN bound to Abeta as a function of the Abeta concentration or by means of the separation of free PIN from bound PIN by centrifugation and subsequent analysis of the supernatant by visible-absorption spectrophotometry. Both methods gave equivalent results. The stoichiometry of PIN binding to Abeta was 1, and the curve representing the concentration effect of Abeta on the concentration of a dye-Abeta complex showed a biphasic curve instead of the hyperbolic curve that is characteristic of weak ligand-macromolecule interactions [e.g., as shown by Congo Red (CR)]). This and the fact that a Scatchard plot could not be fitted to the experimental data suggested that PIN binds tightly to Abeta. A comparison to the interaction of CR with Abeta led us to conclude that PIN is more sensitive than CR.

Topics: Amyloid beta-Peptides; Carbocyanines; Coloring Agents; Congo Red; Molecular Probes; Protein Structure, Secondary; Spectrophotometry

Liposome is one of the major areas of interest in recent years because of its many potential applications. In this paper, three phase states of liposome (micelle, lamellar and reversed hexagonal) were prepared by thin-film hydration method and their structures were observed with electron microscope. We studied the interaction between these phase states and various dyes by UV-visible spectra. As a result, the phase states of liposome can be detected by the color change or the spectroscopic change. Through careful selection, 4 kinds of useful dyes were found to detect different liposome structures, that is 2,6-dichloroindophenol sodium, congred, pinacyanol chloride and calcein. The possible mechanism of the interaction between the phases of liposome and dyes was discussed. The liposome undertakes hydrolysis and forms mixed micelle. The hydrolysis rate of lamellar is faster than that of reversed hexagonal, which makes pH of the solution to decrease and causes a color change of the dyes in a short time. This method can be applied to the separation of natural phosphatides and monitor in the production of liposome.

Topics: 2,6-Dichloroindophenol; Absorption; Carbocyanines; Coloring Agents; Drug Interactions; Fluoresceins; Liposomes; Phase Transition; Spectrophotometry, Ultraviolet

A variety of lariat ethers were employed to solubilize water-soluble cytochrome c in methanol, in which alcohol, ether, ester, amine, and amide functionalities were attached as cation-ligating side arms to 18-crown-6, 15-crown-5, and 12-crown-4 rings. Among these lariat ethers, the alcohol-armed 18-crown-6 derivative offered the highest solubilization efficiency for cytochrome c via supramolecular complexation. The resulting cytochrome c-lariat ether complexes were electrochemically and spectroscopically characterized and confirmed to have redox-active heme structures of 6-coordinate low-spin population in methanol. Some of them catalyzed the oxidation of pinacyanol chloride with hydrogen peroxide in methanol and exhibited higher activities than unmodified cytochrome c and its poly(ethylene glycolated) derivative. Since the supramolecular complexation between lariat ether and cytochrome c includes extremely simple procedures, it provides a facile preparation method of effective biocatalysts working in organic solvents from metalloproteins.

Topics: Carbocyanines; Catalysis; Cytochrome c Group; Electrochemistry; Ethers; Methanol; Oxidation-Reduction; Solubility; Spectrum Analysis

Interaction of Klebsiella K14 capsular polysaccharide with cationic dyes pinacyanol chloride, acridine orange and phenosafranin has been studied by spectrophotometric and spectrofluorometric techniques. The polymer containing both glucuronic acid and pyruvic acid in its repeating unit behaved as a unique polyelectrolyte. It induced blue shift of the absorption band of pinacyanol chloride indicating strong metachromasy. Stoichiometry of the polyanion and the dye cations in the polymer-dye compound (1:2) indicated that both glucuronic acid and pyruvic acid acted as potential anionic sites for interaction with the cationic dye molecules. The stoichiometry of anionic site (of polyanion): cationic site (of dye) in the polymer dye compound was calculated as 1:1. Interaction of the polymer with acridine orange and phenosafranin dyes studied by fluorescence measurements demonstrated Stern-Volmer type of quenching. Equivalent weight of the polymer was determined by spectrophotometric and spectrofluorometric titrations. From the present studies chromotropic property of the polymer was established.

Topics: Acridine Orange; Binding Sites; Carbocyanines; Coloring Agents; Klebsiella; Phenazines; Polysaccharides, Bacterial; Spectrometry, Fluorescence; Spectrophotometry

The effect of five water-miscible organic solvents (tetrahydrofuran, N,N-dimethylformamide, acetonitrile, 2-propanol, and methanol) on the oxidation of pinacyanol chloride (Quinaldine Blue) by horse heart cytochrome c was determined. Hydrogen peroxide was used as the oxidant, and a change in catalytic property of the dissolved protein was observed after a certain threshold concentration of the organic solvent had been reached. The maximum specific activity was correlated with the Dimroth-Reichardt parameter for the solvents, which is directly related to the free energy of the solvation process. The kinetic constants for the oxidation of pinacyanol chloride were determined in systems containing different proportions of tetrahydrofuran. The best catalytic efficiency (kcat/KM,app) was obtained in a system containing 50% tetrahydrofuran in phosphate buffer. In a mixture containing 90% tetrahydrofuran, cytochrome c showed 18% of its maximum activity. The inactivation of cytochrome c was mainly due to the presence of hydrogen peroxide, and a direct correlation was found between the inactivation constant and the concentration of hydrogen peroxide in the system. The chemical modifications and immobilization of cytochrome c were able to change its biocatalytic activity and stability in the organic solvent system. The kinetic constants and the inactivation of three other type c cytochromes, from Saccharomyces cerevisiae, Pseudomonas aeruginosa, and Desulfovibrio vulgaris Hildenborough in a system containing 90% tetrahydrofuran were compared with those of cytochrome c from horse heart. Cytochrome c551 from P. aeruginosa showed the best stability against hydrogen peroxide and a higher catalytic efficiency than that of horse heart cytochrome c.

Topics: Animals; Carbocyanines; Catalysis; Cytochrome c Group; Horses; Hydrogen-Ion Concentration; Kinetics; Solvents; Water

The acidic capsular polysaccharide isolated from Klebsiella K7 induced metachromasy in the cationic dye pinacyanol chloride indicating its chromotropic character. Interaction of the biopolymer with the cationic dye was studied by visible absorption spectrophotometry, and thermodynamic parameters of the interaction evaluated. The polymer induced a metachromatic blue shift in the spectrum from 600 nm to 495 nm. The spectral changes were studied during interaction of the dye with the polymer at different polymer/dye molar ratios (P/D = 0 approximately 50). Effects of co-solvents on the stability of the dye-polymer compound were studied. A complete reversal of metachromasy was observed upon addition of different alcohols and urea solution. Thermodynamic parameters obtained from the spectral data indicated chromotropic character of the polymer in interacting with the cationic dye molecules in solution.

Topics: Carbocyanines; Coloring Agents; Klebsiella; Polysaccharides, Bacterial; Spectrophotometry; Thermodynamics

In the brains of 7 patients with multiple sclerosis, mast cells were observed within the demyelinated plaques, in the border zone of the plaques as well as in seemingly normal white matter. The cells were mostly located in close connection with small vessels. The routine staining with toluidine blue for the demonstration of mast cells is not adequate as compared with staining of similar sections in pinacyanol erythrosine. Mast cells may be a hitherto underestimated contributor to the demyelinating process of multiple sclerosis.

Topics: Brain; Carbocyanines; Erythrosine; Fluoresceins; Histological Techniques; Humans; Mast Cells; Microscopy, Electron; Multiple Sclerosis; Quinolines; Staining and Labeling

Interaction of cationic dye pinacyanol chloride with the acidic capsular polysaccharide isolated from Klebsiella serotype K15 has been investigated by spectral measurements. Klebsiella K15 polysaccharide consists of hexasaccharide repeating units containing one residue each of glucuronic acid and glucose, and four residues of galactose. Glucuronic acid acts as the potential anionic site and the biopolymer interacts with the dye cations. It induces metachromasy in the dye and a blue shift of about 100 nm is observed in the visible absorption spectrum of the dye. Spectral measurements have been carried out at different polymer/dye molar ratios. Stoichiometry of polymer and dye in the polyanion-dye compound (1:1) indicates that every potential anionic site of the polyanion is associated with the dye cation, and stacking conformation is thus suggested. Effect of different non-aqueous solvents in reversing metachromasy has also been studied. Interaction studies exhibit chromotropic character of the biopolymer.

Topics: Bacterial Capsules; Carbocyanines; Coloring Agents; Klebsiella; Polysaccharides, Bacterial; Spectrophotometry

Photobiological activities of pinacyanol chloride (PC), which is known as a non-intercalating dye, were investigated. Irradiation of PC-sensitized yeast cells in the dark brought about marked decrease of survival and induction of "petites" which are respiration-deficient mutants caused by partial loss of mitochondrial deoxyribonucleic acid. Nuclear mutation represented by reversion from Trp- to Trp+ was also induced by photodynamic action of PC. This fact suggested photoactive dyes are not necessarily intercalated for inducing mitochondrial and nuclear mutation. Singlet oxygen production was determined in the photoirradiated PC solution by electron spin resonance spectrometry. Photobiological effects of PC might be brought about mainly by a type II photodynamic mechanism.

Topics: Carbocyanines; Cell Nucleus; Electron Spin Resonance Spectroscopy; Free Radicals; Genes; Mutation; Oxygen; Photochemistry; Saccharomyces cerevisiae; Spectrophotometry

The acidic capsular polysaccharide isolated from Klebsiella K10 exhibited chromotropic character with respect to induction of metachromasy in the cationic dye pinacyanol chloride (1-ethyl-2-[3-(1-ethyl-2(1H)-quinolylidene)propenyl]quinolinium chloride). Klebsiella K10 polymer consists of hexasaccharide repeating units containing one residue of glucuronic acid along with other neutral sugars in each repeating unit. It induces a metachromatic blue shift in the visible absorption spectrum of the dye from 600 nm to 500 nm. The spectral changes have been studied during interaction of the dye cations with the polyanions at different polymer/dye molar ratios. The polyanion-dye compounds are formed with polymer/dye stoichiometry of 1:1, indicating formation of stacking conformation. The complete reversal of polymer-induced metachromasy has also been observed by the addition of ethanol and urea.

Topics: Carbocyanines; Cations; Coloring Agents; Drug Interactions; Hydrogen-Ion Concentration; Klebsiella; Polysaccharides, Bacterial; Quinolines

The polarization optical analysis of human blood platelets was carried out by means of topo-optical staining reactions. Similar studies have not been performed so far. With this approach we were able to demonstrate the spatially oriented nature of glycoprotein components in the platelet membrane. Using a sialic acid specific topo-optical reaction the sialic acid component of human platelet membrane was selectively demonstrated and the even distribution of sialic acid residues on the membrane surface was also suggested. Polarization optical analysis has shown a membrane-parallel orientation of oligosaccharide chains carrying sialic acids.

Topics: Blood Platelets; Carbocyanines; Cell Membrane; Glycoproteins; Histocytochemistry; Humans; Hydrolysis; Methylene Blue; Neuraminidase; Staining and Labeling; Tolonium Chloride

A technique is presented for rapid C-banding of eukaryotic chromosomes with pinacyanol chloride. This technique has given excellent definition and clarity to chromosome bands in plant and animal chromosomes. In permanent mounts the chromosomes did not fade after storage for up to two years.

Topics: Carbocyanines; Chromosome Banding; Chromosomes; Chromosomes, Human; Drug Stability; Humans; Plants; Quinolines; Quinolinium Compounds

The paper reports on the use of a quinoline dye, pinacyanol, towards staining of acid hydrolysed DNA. The dye as an aqueous solution can be used after treatment of mammalian tissue sections in concentrated phosphoric acid at 5 degrees C for 20 min followed by hydrolysis in 6N HCl at room temperature for 15 min, for staining DNA-aldehyde molecules. It has also been observed that staining of DNA-phosphate groups is also possible in sections treated with cold concentrated phosphoric acid after selective extraction of RNA. Both in situ absorption characteristics of stained nuclei as well as in vitro absorption data of an aqueous solution of the dye have been presented. It has been suggested that staining DNA-aldehydes with pinacyanol, without any primary amino group in its molecules is due to a modified Feulgen reaction.

Topics: Animals; Carbocyanines; DNA; Female; Hydrochloric Acid; Hydrogen-Ion Concentration; Hydrolysis; Kidney; Liver; Male; Ovary; Phosphoric Acids; Quinolinium Compounds; Rats; Staining and Labeling; Testis

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Bacteria; Carbocyanines; Coloring Agents; Drug Resistance, Microbial; Microbial Sensitivity Tests; Staining and Labeling

Topics: Carbocyanines; Coloring Agents; Humans; Mast Cells; Staining and Labeling