-
Analytica Chimica Acta Oct 2013The effectiveness of a novel binary matrix composed of 1,8-bis(dimethylamino)naphthalene (DMAN; proton sponge) and 9-aminoacridine (9AA) for the direct lipid analysis of...
1,8-bis(dimethylamino)naphthalene/9-aminoacridine: a new binary matrix for lipid fingerprinting of intact bacteria by matrix assisted laser desorption ionization mass spectrometry.
The effectiveness of a novel binary matrix composed of 1,8-bis(dimethylamino)naphthalene (DMAN; proton sponge) and 9-aminoacridine (9AA) for the direct lipid analysis of whole bacterial cells by matrix assisted laser desorption ionization mass spectrometry (MALDI MS) is demonstrated. Deprotonated analyte signals nearly free of matrix-related ions were observed in negative ion mode. The effect of the most important factors (laser energy, pulse voltage, DMAN/9AA ratio, analyte/matrix ratio) was investigated using a Box-Behnken response surface design followed by multi-response optimization in order to simultaneously maximize signal-to-noise (S/N) ratio and resolution. The chemical surface composition of single or mixed matrices was explored by X-ray photoelectron spectroscopy (XPS). Moreover, XPS imaging was used to map the spatial distribution of a model phospholipid in single or binary matrices. The DMAN/9AA binary matrix was then successfully applied to the analysis of intact Gram positive (Lactobacillus sanfranciscensis) or Gram negative (Escherichia coli) microorganisms. About fifty major membrane components (free fatty acids, mono-, di- and tri-glycerides, phospholipids, glycolipids and cardiolipins) were quickly and easily detected over a mass range spanning from ca. 200 to ca. 1600 m/z. Moreover, mass spectra with improved S/N ratio (compared to single matrices), reduced chemical noise and no formation of matrix-clusters were invariably obtained demonstrating the potential of this binary matrix to improve sensitivity.
Topics: 1-Naphthylamine; Aminacrine; Escherichia coli; Lactobacillus; Lipids; Photoelectron Spectroscopy; Signal-To-Noise Ratio; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 24070484
DOI: 10.1016/j.aca.2013.08.050 -
Chemical Communications (Cambridge,... Oct 2013We describe a gold nanoparticle based assay that can rapidly determine the crosslinking of DNA duplexes by ligands. Such compounds have potential in targeting highly...
We describe a gold nanoparticle based assay that can rapidly determine the crosslinking of DNA duplexes by ligands. Such compounds have potential in targeting highly compacted DNA such as that found in the nucleosome.
Topics: Aminacrine; DNA; Gold; Hydrogen-Ion Concentration; Ligands; Metal Nanoparticles; Nucleosomes; Spectrophotometry, Ultraviolet
PubMed: 23995794
DOI: 10.1039/c3cc45600e -
European Journal of Mass Spectrometry... 2013Matrix-assisted laser desorption/ionization (MALDI) has been shown to be highly sensitive for analyzing low-mass compounds such as metabolites if the right matrix is...
Matrix-assisted laser desorption/ionization (MALDI) has been shown to be highly sensitive for analyzing low-mass compounds such as metabolites if the right matrix is used. 9-aminoacridine (9AA) is the most commonly employed matrix for negative mode MALDI-MS in metabolomics. However, matrix interferences and the strongly varying sensitivity for different metabolites make a search for alternative matrices desirable, in order to identify compounds with a different chemical background and/or favoring a different range of analytes. We tested the performance of a series of potential negative mode MALDI matrices with a mix of 29 metabolites containing amino acids, nucleotide phosphates and Krebs cycle intermediates. While ethacridine lactate was found to provide limits of detection (LODs) in the low femtomole range for nucleotide phosphates, amino acids and Krebs cycle intermediates in the low picomole range, 4-amino-2-methylquinoline showed LODs in the picomole range for most metabolites, but is capable of ionizing a broader range of analytes than both 9AA and ethacridine.
Topics: Aminacrine; Amino Acids; Aminoquinolines; Ethacridine; Limit of Detection; Metabolomics; Nucleotides; Quinaldines; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 23841224
DOI: 10.1255/ejms.1209 -
Organic & Biomolecular Chemistry Jun 2013On deprotonation, 1-arylindazolium salts form 1-arylindazol-3-ylidenes which rearrange spontaneously via ring cleavage, ring closure and subsequent proton transfer to...
On deprotonation, 1-arylindazolium salts form 1-arylindazol-3-ylidenes which rearrange spontaneously via ring cleavage, ring closure and subsequent proton transfer to substituted 9-aminoacridines. By contrast, the N-heterocyclic carbene of 2-phenylindazolium cannot rearrange similarly and was trapped by sulfur.
Topics: Aminacrine; Cyclization; Indazoles; Methane; Molecular Structure; Palladium
PubMed: 23613125
DOI: 10.1039/c3ob40379c -
Bioorganic & Medicinal Chemistry Jun 2013Caffeine (CAF) and other methylxanthines (MTX) may interact directly with several aromatic, intercalating ligands through mixed stacking aggregation. Formation of such...
Caffeine (CAF) and other methylxanthines (MTX) may interact directly with several aromatic, intercalating ligands through mixed stacking aggregation. Formation of such stacking hetero-complexes may decrease their free form concentration and, in consequence, diminish their biological activity, which is often related to their direct interaction with DNA. In this paper interactions of acridine mutagen (ICR191) with DNA in the presence of three MTX: caffeine (CAF), pentoxifylline (PTX) and theophylline (TH) are investigated. Several mathematical models are used to calculate all association constant values and every component concentration in each analyzed mixture. Model McGhee-von Hippel is used to analyze ligand-DNA interaction, and model Zdunek et al.--to analyze ligand-MTX interactions. Finally, two distinct mathematical models are employed to analyze three-component mixture containing ligand, MTX and DNA molecules. The first model describes possible interactions of ligand with DNA and MTX, and rejects direct MTX interactions with DNA. The second model describes all interactions mentioned above and, additionally, allows MTX to interact directly with DNA. Results obtained using these models are similar. However, correspondence of theoretical results to experimental data is better for the first model than the second one. In this paper possible interactions of ICR191 with eukaryotic cell chromatin are also analyzed, showing that CAF reduces acridine mutagen potential to interact directly with cell chromatin. Additionally, it is demonstrated that MTX inhibit mutagenic activity of ICR191 in a dose-dependent manner. Furthermore, biological activity of ICR191-MTX mixtures corresponds with concentration of free mutagen form calculated using appropriate mathematical model.
Topics: Aminacrine; Animals; Caffeine; Cattle; DNA; Drug Antagonism; Epithelial Cells; Intercalating Agents; Kidney; Kinetics; Models, Chemical; Mutagens; Nitrogen Mustard Compounds; Pentoxifylline; Salmonella typhimurium; Theophylline; Thermodynamics
PubMed: 23601817
DOI: 10.1016/j.bmc.2013.03.043 -
Analytica Chimica Acta Mar 2013This report focuses on the heterogeneous distribution of small molecules (e.g. metabolites) within dry deposits of suspensions and solutions of inorganic and organic...
This report focuses on the heterogeneous distribution of small molecules (e.g. metabolites) within dry deposits of suspensions and solutions of inorganic and organic compounds with implications for chemical analysis of small molecules by laser desorption/ionization (LDI) mass spectrometry (MS). Taking advantage of the imaging capabilities of a modern mass spectrometer, we have investigated the occurrence of "coffee rings" in matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) sample spots. It is seen that the "coffee-ring effect" in MALDI/SALDI samples can be both beneficial and disadvantageous. For example, formation of the coffee rings gives rise to heterogeneous distribution of analytes and matrices, thus compromising analytical performance and reproducibility of the mass spectrometric analysis. On the other hand, the coffee-ring effect can also be advantageous because it enables partial separation of analytes from some of the interfering molecules present in the sample. We report a "hidden coffee-ring effect" where under certain conditions the sample/matrix deposit appears relatively homogeneous when inspected by optical microscopy. Even in such cases, hidden coffee rings can still be found by implementing the MALDI-MS imaging technique. We have also found that to some extent, the coffee-ring effect can be suppressed during SALDI sample preparation.
Topics: Aminacrine; Coffee; Graphite; Metal Nanoparticles; Platinum; Spectrometry, Fluorescence; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tin Compounds
PubMed: 23427803
DOI: 10.1016/j.aca.2012.12.044 -
Methods in Molecular Biology (Clifton,... 2013Capillary electrophoresis is a common technique used for glycosaminoglycan-derived disaccharide analysis because of its high resolving power, high separation efficiency,...
Capillary electrophoresis is a common technique used for glycosaminoglycan-derived disaccharide analysis because of its high resolving power, high separation efficiency, high sensitivity, short analysis time, and straightforward operation. CE coupled to laser-induced fluorescence (LIF) detection shows an approximately 100 times higher sensitivity than traditional UV detection at 232 nm. 2-Aminoacridone (AMAC) is a widely used fluorophore for labeling unsaturated disaccharides by deductive amination, which is one of the most important method of derivatization of disaccharides for CE-LIF detection. Outlined in this chapter is a protocol of analyzing glycosaminoglycan-derived disaccharides by CE-LIF with AMAC derivatization.
Topics: Aminacrine; Calibration; Carbohydrate Conformation; Carbohydrate Sequence; Disaccharides; Electrophoresis, Capillary; Glycosaminoglycans; Reference Standards
PubMed: 23386338
DOI: 10.1007/978-1-62703-296-4_7 -
The Journal of Physical Chemistry. A Feb 2013We aim to find out the extent of stability of the excimer of 9-aminoacridine hydrochloride hydrate (9AA), a prospective PDT drug, in different confined media with...
We aim to find out the extent of stability of the excimer of 9-aminoacridine hydrochloride hydrate (9AA), a prospective PDT drug, in different confined media with varying cavity size. When confined in cetyltrimethyl ammonium bromide micelles, although at low concentration of 9AA, only a single distinct peak (λ(max) at 460 nm) with a shoulder at 485 nm is observed in steady-state fluorescence spectrum, yet with increase in concentration the peak and the shoulder merge with simultaneous emergence of another peak at 535 nm, which is assigned to excimer. Similar behavior is also observed in Triton-X, crown ether, α-cyclodextrin, β-cyclodextrin, and homogeneous aqueous medium. The formation of excimer, which reflects the extent of confinement of 9AA, is maximum in β-cyclodextrin followed by others. Steady-state and time-resolved fluorescence studies along with TRES and TRANES analyses coupled with anisotropy data and transient absorption studies reveal the presence of monomer-dimer equilibrium of 9AA in the excited state. Molecular modeling indicates that the structure of excimer is stabilized by locking of the two monomeric species via four hydrogen bonds formed between the amino-H and imino-N of 9AA monomers, whereas the dimer in the ground state has only two such hydrogen bonds.
Topics: Aminacrine; Computer Simulation; Dimerization; Hydrogen Bonding; Models, Molecular; Spectrum Analysis; Water
PubMed: 23346864
DOI: 10.1021/jp3103639 -
TSitologiia I Genetika 2012All the methanol extracts did not show mutagenic activity in Ames/Salmonella and Z. mays MI test systems. Furthermore, some extracts showed significant antimutagenic...
All the methanol extracts did not show mutagenic activity in Ames/Salmonella and Z. mays MI test systems. Furthermore, some extracts showed significant antimutagenic activity against 9-AA in Ames test system. Inhibition rates for 9-AA mutagenicity ranged from 25.51% (P. furfuracea - 0.05 microg/plate) to 66.14% (C. islandica - 0.05 microg/plate). In addition, all of the extracts showed significant antimutagenic activity against sodium azide (NaN3) mutagenicity on MI values of Z. mays.
Topics: Aminacrine; Antimutagenic Agents; Complex Mixtures; Lichens; Methanol; Mitosis; Mitotic Index; Mutagenicity Tests; Mutagens; Plant Roots; Salmonella typhimurium; Sodium Azide; Solvents; Turkey; Zea mays
PubMed: 23342647
DOI: No ID Found -
Genetika Oct 2012We studied the influence of three derivatives of pyrido[1,2alpha]benzimidazoles (PBIs), which have DNA-intercalating properties, on plant mitotic chromosome...
We studied the influence of three derivatives of pyrido[1,2alpha]benzimidazoles (PBIs), which have DNA-intercalating properties, on plant mitotic chromosome condensation, in order to increase the resolution of chromosome analysis. The efficiency of the influence of these agents was assessed using the median chromosome length on chromosome slides, as well as by the number and size of chromosome DAPI bands. We used the third chromosome of Linum grandiflorum Desf. in these experiments. The chromosome was identified on the slides using its DAPI band pattern and a molecular marker, viz., the 5S rDNA site, which is located in the proximal region of the long arm of the chromosome. The influence of the well-known 9-aminoacridine (9-AMA) DNA intercalator, which is widely used in karyotype studies of short-chromosome organisms, was used as a control in all of the experiments. It was found that the influence of each of the three PBIs in the study on the root meristem of L. grandiflorum resulted in an increase in the median length of the third chromosome, the linear centromeric DAPI band size, and the number ofintercalary DAPI bands. All three PBIs acted more efficiently than 9-AMA. The median chromosome length was increased by 15-40% and the number of intercalary bands increased by 1.5-3 times after PBI treatment, as compared to 9-AMA treatment. At the same time, 7-CF3-PBI, in a similar manner to 9-AMA, did not change the relative size of the centromeric DAPI band, while 7-NH2-PBI and 7-CF3-9-NH2-PBI gradually increased this parameter. It is concluded that these substances can be used as intercalating agents in cytogenetic studies in order to increase the resolution of chromosome analysis.
Topics: Aminacrine; Benzimidazoles; Chromosome Banding; Chromosomes, Plant; DNA, Ribosomal; Flax; Indoles; Intercalating Agents; Karyotyping
PubMed: 23270272
DOI: No ID Found