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PubMed1984

Comparison of Na+/H+ and Cl-/OH- exchange in rat jejunal brush border membrane vesicles: studies with acridine orange.

Vesicles can accumulate the fluorescent dye acridine orange if their intravesicular space is acidic compared with the external one. The quenching of the acridine orange fluorescence was used to monitor the formation and the dissipation of a delta pH in brush border vesicles isolated from rat kidney cortex or rat jejunum. Similar findings were obtained with both brush border membrane vesicles preparations. Under condition of potassium efflux, acridine orange fluorescence was quenched only in the presence of valinomycin showing a H+ greater than K+ conductance. Under condition of sodium efflux, an acidification of the intravesicular space occurred due to: a) indirect (electrical) coupling of sodium and proton fluxes; b) directly coupled Na+/H+ exchange. It is possible to preseta delta pH across the vesicles (pHin less than pHout) and to monitor the rate of the delta pH dissipation. The initial rate of dissipation of a preset delta pH was accelerated in a saturable manner by pulse-injections of sodium, this phenomenon is sensitive to the inhibition of Amiloride; Lithium can partially replace sodium. An inwardly directed chloride gradient did not induce an appreciable intravesicular acidification. On the other hand a Na-gluconate (in greater than out) gradient and a similar NaCl gradient produced the same intravesicular acidification. Furthermore the initial rate of dissipation of a preset delta pH was accelerated for the same extent by pulse injections of Na-gluconate and NaCl. These findings clearly confirm the existence of the Na+/H+ exchange. In contrast the Cl-/OH- exchange, if at all present, operates, in these brush border membrane preparation, at a much lower rate than Na+/H+ exchange.

Acridine Orange↗
PubMedDate not supplied

[Protonation of acridine in a hydrated protein matrix].

Fluorescence of polycrystaline acridine in the matrix of solid alpha-chymotrypsin was studied at different humidities of the atmosphere. The fluorescence was not changed when the mixture was extensively dried. At intermediate and high humidities two consecutive processes proceed: 1) the solid-state dissolution of acridine crystals in the protein matrix and 2) the capture of protons by dispersed acridine molecules due to the proton transport through H-bound chains of water molecules from the protein proton-donor groups.

Acridines↗
PubMed1980

Lysosomal acridine orange uptake in fibroblasts transformed by SV40 or human cytomegalovirus.

Lysosomes of living human fibroblasts, SV40-transformed rat fibroblasts and human CMV-transformed hamster fibroblasts were examined by fluorescence microscopy after pretreatment with acridine orange at a supravital concentrations (5 x 10(6) M). Dye uptake by human primary fibroblast lysosomes was considerable and independent of the age of the cultures. In the transformed cultures, cytoplasmic granular red fluorescence indicating lysosomal acridine orange uptake could not be observed in part of the cells; cells showing no cytoplasmic granular fluorescence appeared as early as after 48 hr incubation and were growing in dependence on the age of the culture. Staining of living cells by acridine orange solutions at supravital concentration is a practicable method for the examination of functional changes of lysosomes.

Acridine Orange↗
PubMed1981

[Action of acridine dyes on antibiotic, pigment and aerial mycelium formation in streptomycete producers of multicomponent antibiotics].

The ability of 5 streptomycetous species synthesizing multicomponent antibiotic to produce the antibiotic and water-soluble pigment and to form the aerial mycelium in the presence of acridine dyes was studied. It was found that the character of the produced complex changed, when acridine dyes were added to the medium under conditions not affecting the culture growth and the temperature was elevated. Colonies deficient with respect to formation of the aerial mycelium and with changed pigment and antibiotic production were detected in the monospore cultures of the streptomycetes treated with acridine dyes, when the spore survival was equal to 100 percent, the frequency of the colonies being about 40 per cent.

Acridines↗
PubMed1995

Immunomodulating effect of acridine tautomers on eukaryotic cells.

The immunomodulating effect of some new amino- and imino-acridine derivatives, were investigated on antibody dependent cellular cytotoxicity (ADCC) and induced-blast transformation of lymphocytes. In different concentrations (2.0 x 10(-6) M, 4.0 x 10(-8) M and 2.0 x 10(-5) M) the drugs produced a suppression of PHA and ConA induced cell proliferative response except in the case of 2b, 2d and 2g amino-acridines. The suppressive effects were dose dependent and exhibited a higher inhibitory level in the case of imino-acridines. Some drugs at low concentration exerted a little enhancing effect on ADCC reaction.

Acridines↗
PubMed1995

Activity and structure relationship of acridine derivatives against African trypanosomes.

48 newly synthesized acridine derivatives of different classes were screened for antitrypanosomal activity. They showed a dose dependent effect on Trypanosoma rhodesiense and T. brucei bloodstream forms measured by the inhibition of esterase activity in a fluorescence based in vitro assay. After analysis of the IC50 and MIC values of the investigated acridines it was obvious that no new compound reached the level of the trypanocidal drugs in use (50 ng/ml). Most of the derivatives had IC50 values in the range of 1 to 10 micrograms/ml. 9 derivatives from different classes of acridines were in vitro active below 1 microgram/ml. Correlations between structure and effect on trypanosomes have been elucidated by comparing the IC50 and MIC values of these compounds, in the course of which no significant differences in the drug susceptibility between T. brucei und T. rhodesiense was noticed. The dialkylaminoalkyl derivatives among the group of the 9-thioacridines were slightly more potent than the mono-alkylated ones. 1,2,3,4-tetrahydro-9-thioacridines showed the influence of higher substituted side chains on the trypanocidal activity in the same way as 9-thioacridines. The corresponding ketones of 9-thioacridines confirmed the tendency of increasing toxicity due to the derivatisation of the dialkylaminoalkyl side chain. Within the series of the 9-aminoacridines the elongation of the side chain did not markedly change the activity, however the IC50 values are generally low between 0.13 and 1.2 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Acridines↗
PubMed1964

ACRIDINE ORANGE BINDING BY MICROCOCCUS LYSODEIKTICUS.

Beers, Roland F., Jr. (Johns Hopkins University, Baltimore, Md). Acridine orange binding by Micrococcus lysodeikticus. J. Bacteriol. 88:1249-1256. 1964.-Micrococcus lysodeikticus cells bind acridine orange (AO) reversibly. The adsorption isotherm is consistent with a highly cooperative-type binding similar to that observed with polyadenylic acid. The cells exhibit a strong buffering action on the concentration of free AO which remains constant (1 mug/ml) over a range from 5 to 95% saturation of the cells by AO. The cells stain either fluorescent orange or green. The fraction stained orange is directly proportional to the quantity of dye adsorbed, indicating that these cells bind a fixed amount of AO (10% of dry weight). The green-stained cells contain less than 1% of the AO bound to orange-stained cells. The results suggest that the abrupt increase in amount of AO bound by the orange-stained cells occurs when the concentration of free AO reaches a threshold concentration. Similar results were obtained with Bacillus cereus. Mg increases the free AO concentration and the extent of binding capacity of the cells.

Acridine Orange↗
PubMed1990

Molecular recognition between oligopeptides and nucleic acids. DNA sequence specificity and binding properties of an acridine-linked netropsin hybrid ligand.

The binding to DNA of a mixed function ligand (NETGA) is described, in which a potential intercalating group, an acridine moiety, is incorporated at the carboxyl terminus of the minor groove binding oligopeptide netropsin skeleton. Scatchard analysis of absorption data provided evidence of two modes of binding to DNA with K1 = 9.1 x 10(5) M-1 at low r values (0.003-0.1), and a binding site size n = 10, indicative of binding of both moeities. At high binding ratios (greater than 0.1), K2 = 0.9 x 10(5) M-1 and n = 5 corresponding to external binding. Complementary strand MPE footprinting on a pBR322 restriction fragment showed NETGA binds to 5'-AAAT like netropsin. It causes enhanced cleavage by MPE, particularly at G-C rich sequences and remote from the preferred binding sites. Viscometry measurements provided evidence for biphasic modes of the two binding portions of NETGA. Fluorescence polarization and linear dichroism measurements were in accord with distinct modes of interaction of the acridine (intercalation) and oligopeptide (minor groove binding) portions of NETGA. LD measurements on NETGA indicate that the oligopeptide moiety (netropsin-like) has an orientation typical of minor groove binders, whereas the degree of intercalation of the acridine group is decreased by association of the oligopeptide moiety.

Aminoacridines↗
PubMed1989

On the glucose effect in acridine-induced frameshift mutagenesis in Escherichia coli.

Log-phase cells of E. coli growing in defined minimal media were washed, exposed to acridines in the same minimal salts solution, and plated to select for Nad+ revertants. At low mutagen concentration, treatment in the presence of the carbon source to which the cells were adapted resulted in a decrease in revertant yield of several orders of magnitude compared with the yield in the absence of a carbon source. At high mutagen concentration, however, a carbon source present during treatment caused a 2- to 150-fold increase in revertant yield (depending on the mutagen, the carbon source, and on the genetic background of the strain). In a strain lacking adenylate cyclase, acridine mutagenesis was not abolished under the experimental conditions used in this study, and the addition of cAMP during mutagenic treatment had no effect. In mismatch repair-deficient strains, the presence of glucose during treatment with low mutagen concentration did not cause a decrease in revertant yield as drastic as in the wild type. From the results reported here, we conclude that the glucose effect in acridine mutagenesis is due to an enhancement of mismatch repair.

Aminacrine↗
PubMed2004

Reactivity of pyrido[4,3,2-kl]acridines: regioselective formation of 6-substituted derivatives.

Pyrido[4,3,2-kl]acridines represent a new class of heterocycles, isomers of marine alkaloids. The 7H-pyrido[4,3,2-kl]acridine reacts as an electron rich heterocycle, and in particular via electrophilic substitution such as H/D exchange and the Vilsmeier-Haack reaction. The reaction is fully regioselective and gives the corresponding 6-substituted derivatives. The pyrido[4,3,2-kl]acridin-4-one reacts with amines and thiol, via 1,4-Michael addition to give the 6-amino or 6-thio analogues in a very efficient way. Molecular calculations account for the observed regioselectivity.

Journal Article↗
PubMed2000

Bis(acridine-N)(nitrato-O,O')silver(I).

The title complex, [Ag(NO(3))(C(13)H(9)N)(2)], is the first complex of silver and acridine to be reported. The silver coordination is distorted trigonal. The N-Ag-N angle involving the N atoms of the acridine ligands is 145.84 (6) degrees. The nitrate ion coordinates to silver as an asymmetrically chelating bidentate ligand. The crystal structure consists of neutral complex molecules linked into chains by means of attractive pi-pi interactions among the parallel acridine ligands.

Journal Article↗
PubMed2005

9-(2,6-Difluorophenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonate and its precursor 2,6-difluorophenyl acridine-9-carboxylate: C-H...O, C-F...pi, S-O...pi and pi-pi stacking interactions.

The title compounds, C21H14F2NO2+.CF3SO3-, (I), and C20H11F2NO2, (II), form monoclinic and triclinic crystals, respectively. Adjacent cations of (I) are oriented in a ;head-to-tail' manner and are linked to one another via networks of C-H...O, C-F...pi, S-O...pi and multidirectional pi-pi interactions. Adjacent molecules of (II) are also arranged in a ;head-to-tail' manner and are linked via networks of C-H...O and multidirectional pi-pi interactions. The mean planes of the acridine moieties lie parallel in the lattices of both compounds. The benzene rings are also parallel. However, the acridine and difluorophenyl rings are mutually oriented at an angle of 17.3 (2) degrees in (I) and 5.8 (2) degrees in (II). This mutual orientation in various phenyl acridine-9-carboxylates and related compounds is strongly influenced by the nature of the substituents on the phenyl fragment.

Journal Article↗
PubMed1983

Characterization of five commercially available samples of acridine yellow.

Commercial samples of acridine yellow, all labeled C.I. 46025, have been analyzed by thin layer chromatography, UV and visible light spectroscopy, mass spectrometry, and photodynamic efficiency in the inactivation of bacteriophage phi X174. Three types of sample were clearly delineated: i) true acridine yellow (3,6-diamino-2,7-dimethylacridine) whose spectral and chromatographic properties are very close to those of proflavine (3,6-diaminoacridine); ii) a pure but different dye tentatively identified as euchrysine (3,6-diamino-2,7,9-trimethylacridine), since on the basis of mass spectral data, it contains an additional methyl group not fixed on the amino groups; and iii) a complex dye with its own special properties and whose main yellow component has a molecular weight and a mass spectrum compatible with an overall formula of C16H16N2S. The three types of dye could be distinguished on the basis of simple tests. Acridine yellow is photodynamically almost as efficient as proflavine, but the two other dyes are very poor sensitizers.

Aminoacridines↗
PubMed1995

Comparison of Giemsa and acridine orange stains for the diagnosis of Leishmania donovani in biopsies of infected hamsters.

Identical impression smears of spleen, liver and bone marrow biopsy materials from Leishmania donovani-infected hamsters were stained using either acridine orange or Giemsa. Spleen parasite-loads calculated from the two stains for identical biopsy material were significantly different from each other. However, liver and bone marrow parasite- loads calculated from either Giemsa-stained or acridine orange-stained biopsies were not significantly different from each other. This study has shown that acridine orange, which is a quick and simple technique, has great potential in the diagnosis of kala-azar when liver and bone marrow biopsies are used.

Journal Article↗
PubMed2001

[Spectrophotometric determination of nitrite ion with acridine red based on the nitrosation reaction].

A new spectrophotometric method for the determination of nitrite ion was studied. The method is based on the nitrosation reaction of acridine red with nitrite ion in hydrochloric acid medium. The decolorization of acridine red by the reaction with nitrite was used to spectrophotometric determination at 525 nm. The optimum experimental conditions have been confirmed and 6 mol.L-1 hydrochloric acid is 1.5 mL; 5 x 10(-4) mol.L-1 acridine red is 2.0 mL, the reaction time is 20 min. On the selected conditions, Beer's law is obeyed and the linear range for the determination is 0.025-0.5 microgram.mL-1 NO2-.28 coexistent ions were examined and no serious interference for most of ions was observed. The method has been applied to determine nitrite ion in four water samples with satisfactory results. The relative standard deviation was less than 2.6% for 5 measurements in each water sample. A preliminary relation mechanism is supposed.

Hydrochloric Acid↗
PubMed2001

[Study on the energy transfer fluorescence quenching among combination of acridine yellow-PAR determination of trace iron].

An energy transfers technique between 4-(2-Pyridylazo) resorcinol(PAR) and acridine yellow is studied, and optimum experimental conditions of energy transfer is done as well. It is found that in the aqueous solution of sodium lauryl sulfate, NH3.H2O-NH4Cl buffer solution at pH = 9.2, the energy transfers from acridine yellow to iron(II)-PAR complexes. So a new method of fluorometric energy transfers determination of trace iron(II) by acridine yellow--PAR was described. The range of determination of iron is 0-10 micrograms.L-1. The detection limit for iron is 0.06 microgram.L-1. The method has been applied to the determination of iron in water sample and hair with satisfactory results.

Aminoacridines↗
PubMed1979

Pharmacological studies on new oncostatic acridine derivatives. II. Chronic action.

Encouraging results of preclinical pharmacologic analysis prompted the following study on the chronic action of N10-oxide 1-nitro-9-/3-dimethylaminopropylamino/-acridine (C-666) and 1-nitro-9- [/2-dimethylamino/ -1-methylethylamino] -acridine (C-829). Toxic influence of both compounds on liver, kidneys, gonads and intestine epithelium was observed. These histological changes were not, however, followed by any disorders in functions of liver and gonads. Only administration of compound C-666 was followed by the decrease of filtration of renals glomuses. A slight involutional influence of acridine derivatives on lymphopoetic reproductive center of thymus and lymph nodes was observed. At the same time there were no disorders in the value of circular leukocyte system. It was stated that the investigated compounds had no effect on the system of the red cells of the blood; only blood clotting time was prolonged. Compounds C-666 and C-829 did not inhibit the growth of tested animals.

Aminoacridines↗