Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “NAPHTHALENE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources
PubMed2001

4-(Phenyldiazenyl)naphthalen-1-amine and its hydrochloride.

The crystal structures of 4-(phenyldiazenyl)naphthalen-1-amine, C(16)H(13)N(3), (I), and its hydrochloride, (4-aminonaphthalen-1-yl)phenyldiazenium chloride, C(16)H(14)N(3)(+) x Cl(-), (II), have been determined from X-ray single-crystal and powder data, respectively. The effect of the crystal environment on the molecular electronic structure was analysed on the AM1 level. One of the two symmetry-independent molecules in (I) is involved in intermolecular hydrogen bonding, so that its dipole moment is twice as large as that of the other molecule. The cations in (II) form stacks along [100], with the Cl(-) anions forming hydrogen bonds to all three H atoms attached to N atoms.

Journal Article↗
PubMed2001

Diaquabis(ethylenediamine)copper(II) bis[tris(ethylenediamine)nickel(II)] tris(naphthalene-2,6-disulfonate) tetrahydrate.

The title mixed-metal compound, [Cu(C(2)H(8)N(2))(2)(H(2)O)(2)][Ni(C(2)H(8)N(2))(3)](2)(C(10)H(6)O(6)S(2))(3).4H(2)O, was obtained during investigations of the porous frameworks constructed by amino-coordinated metal complex cations and large organic anions. All three naphthalene-2,6-disulfonate anions and the [Cu(en)(2)(H(2)O)(2)](2+) cation are located on crystallographic inversion centers and assemble into an extended two-dimensional network through intermolecular hydrogen bonds, creating cavities in which the [Ni(en)(3)](2+) cations and water molecules are included.

Journal Article↗
PubMed2001

Di-mu-chloro-bis([2-[N,N-bis(2-aminoethyl)amino-kappa3N]ethylaminium]-copper(II)) bis(naphthalene-1,5-disulfonate) pentahydrate.

The title compound, [Cu2(C6H19N4)2Cl2](C10H6O6S2)2*5H2O, is comprised of discrete [Cu2(tren)2Cl2]2+ dimers [tren is 2-[N,N-bis(2-aminoethyl)amino]ethylaminium] and naphthalene-1,5-disulfonate anions. Two Cl- anions bridge two Cu(II) ions, each of which is also coordinated by two of the primary and the tertiary amino N atoms of the tren ligand, giving each metal atom a distorted square-pyramidal coordination geometry. The cation lies about an inversion centre and the asymmetric unit also has two independent anions lying about inversion centres.

Journal Article↗
PubMed2005

Bis{1-[N-(2-methoxyphenyl)iminomethyl]naphthalen-2(1H)-onato-kappa3O,N,O'}zinc(II) ethanol solvate.

In the crystal structure of the title compound, [Zn(C18H14NO2)2].C2H6O, the Zn atom displays a highly distorted octahedral coordination involving the O and N atoms of two molecules of the Schiff base 1-[N-(2-methoxyphenyl)iminomethyl]naphthalen-2(1H)-one, which acts as an O,N,O'-tridentate ligand. The ethanol molecule is bound to the methoxy group of one ligand molecule via a hydrogen bond.

Journal Article↗
PubMed2006

N,N'-bis(2-methoxyphenyl)naphthalene-1,4-dicarboxamide.

The title compound, C26H22N2O4, crystallizes in an anti-C=O orientation, with the two N-substituted benzene rings in different conformations relative to the naphthalene ring. These conformations allow two strong N-H...O hydrogen bonds and one C-H...pi interaction to generate molecular chains in the cell.

Journal Article↗
PubMed2006

Poly[[di-mu3-acetato-di-mu2-aqua-diaqua-di-mu3-hydroxo-tricopper(II)] naphthalene-1,5-disulfonate].

The crystal structure of the title complex, {[Cu3(C2H3O2)2(OH)2(H2O)4](C10H6O6S2)}n, is built of infinite polymeric cationic {[Cu3(C2H3O2)2(H2O)4(OH)2]2+}n chains stretching along the a axis, with naphthalene-1,5-disulfonate (1,5-nds) anions in between. One independent Cu(II) cation and the 1,5-nds anion occupy special positions on crystallographic inversion centres. Each Cu(II) cation has an octahedral coordination environment formed by two carboxyl O atoms, two hydroxo O atoms and two water molecules. The carboxylate and hydroxo groups perform a bridging function, linking adjacent Cu atoms in the chain, with a shortest Cu...Cu distance of 2.990 (3) A. The chains are further linked into a three-dimensional supramolecular framework via hydrogen-bonding interactions involving the sulfonate groups of the 1,5-nds dianions.

Journal Article↗
PubMed2006

Exploration of the high-pressure behaviour of polycyclic aromatic hydrocarbons: naphthalene, phenanthrene and pyrene.

The structural response of three members of the family of polycyclic aromatic hydrocarbons (PAHs) to high-pressure recrystallization from dichloromethane solutions is presented. Recrystallization of naphthalene in the 0.2-0.6 GPa pressure range does not result in the formation of a new polymorph. Furthermore, direct compression of a single crystal to 2.1 GPa does not result in a phase transition. A density decrease of 18.2% over the 0.0-2.1 GPa pressure range is observed and the principal effect of pressure is to ;tighten' the herringbone structural motif and decrease the size of void regions. A new polymorph of pyrene, form III, has been crystallized at 0.3 and at 0.5 GPa. Structural investigation of this new polymorph by means of topological analysis and comparison of Hirshfeld surfaces and fingerprint plots shows that intermolecular interactions are substantially different from those found in the ambient-pressure structures, and do not fit a previously established packing model for PAHs. Similar discrepancies are found for the high-pressure polymorph of phenanthrene, which is here re-investigated in greater detail. The structures of these high-pressure polymorphs are dominated by pi...pi stacking with a limited contribution from C-H...pi (peripheral) interactions. It is perhaps not surprising that high-pressure polymorphs deviate from a model that has been devised for ambient-pressure structures, and this may be a direct consequence of the ability of pressure to modify and combine intermolecular interactions in ways that are not usually found at ambient pressure. This is achieved by modifying the relative orientations of molecules and by encouraging the formation of denser structures in which molecules pack together more efficiently.

Journal Article↗
PubMed2000

Pseudo-symmetry characterization and refinement of a trigonal crystal form of naphthalene 1,2-dioxygenase.

Two trigonal crystal structures of naphthalene 1,2-dioxygenase from Pseudomonas sp. NCIB 9816-4 have been refined at 2.6 A resolution. The space group is R3, with four heterodimers in the asymmetric unit. The crystallographic threefold axis coincides with the symmetry axis of the active molecule, a mushroom-shaped alpha(3)beta(3) hexamer. The crystal is formed by symmetrical contacts between the hexamers on three different interaction surfaces, one on the beta-subunit and the other two on the alpha--subunits. Nickel ions mediate one of the alpha-subunit interactions. The two other types of packing contacts sustain two interlaced and almost independent crystal patterns with significantly different temperature factors. The space group of the individual crystal patterns is R32, with the corresponding twofold axes parallel to each other. The interactions between the crystal patterns separate the two parallel twofolds, eliminating the twofold symmetry for the whole crystal. The differences in temperature factors among the molecules in the asymmetric unit have been refined and are different for the two refined structures. An analysis of the structure factors of the pseudo-equivalent reflections showed that their differences lie in their phases and not in their amplitudes, suggesting that R(merge) is not an appropriate indicator for revealing the correct point group.

Bacterial Proteins↗
PubMed1979

The binding of 1-anilino-8-naphthalene sulfonate to the hemocyanin of Octopus vulgaris.

The binding of 1-anilino-8-naphthalene sulfonate (ansyl) to native and copper-free hemocyanin of Octopus vulgaris has been studied in different conditions by measuring the fluorescence properties of the probe in the presence of hemocyanin. Native hemocyanin, either in the oxygenated or in the deoxygenated state, does not bind ansyl. The binding of ansyl with apohemocyanin induces a strong increase (from 0.004 to 0.6 -- 0.7) of the quantum yield and a blue shift from 520 nm to 460 nm of the emission maximum indicating the presence of ansyl binding sites in the protein. Experimental evidence is reported that the binding occurs at the copper-binding site of the protein. The dissociation constants of the ansyl-hemocyanin complexes are equal to about 10(-4) M, i.e. they are of the same order of those obtained with other proteins. The number of binding sites (n) of apohemocyanin for ansyl depends on the conformational state of the protein and ranges from 0.15 -- 0.80 mol/mol protein (Mr 50,000), depending on pH, ionic strength, and urea concentration. A negative interaction between the ansyl binding sites has been suggested.

Anilino Naphthalenesulfonates↗
PubMed1982

5-Isothiocyanato-1-naphthalene azide and rho-azidophenylisothiocyanate. Synthesis and application in hydrophobic heterobifunctional photoactive cross-linking of membrane proteins.

Two hydrophobic, heterobifunctional azidoarylisothiocyanates have been synthesized. The reagents are applicable for group-directed modification of membrane-integrated protein segments and subsequent photo-induced cross-linking with neighbouring membrane constituents. Both 5-isothiocyanato-1-naphthalene azide and p-azidophenylisothiocyanate are chemically characterized with respect to structure and photosensitivity. The reagents compete for the documented phenylisothiocyanate binding site(s) in bacteriorhodopsin and to the anion-exchange protein (band 3) of human erythrocytes. Photoactivation of azidoarylisothiocyanate-labeled membrane proteins leads to homopolymers when cross-linked in purple membranes or in vesicles enriched in the anion-exchange protein.

Anion Exchange Protein 1, Erythrocyte↗
PubMed2006

p-hydroxylation reactions catalyzed by naphthalene dioxygenase.

In this study, naphthalene dioxygenase is shown to catalyze the oxidation of methylphenols and chlorophenols by p- and/or o-hydroxylation reactions. For instance, m-cresol was oxidized to methylhydroquinone with formation of 3- and 4-methylcatechol as minor products. 2-Chlorophenol was exclusively oxidized to chlorohydroquinone, which is an important building block for pharmaceutical products and other organic compounds. The oxygen incorporated in the p-hydroxylation reaction from m-cresol is derived from water with consumption of O2.

Chlorophenols↗
PubMed2003

The aminotetraline derivative (+/-)-(R,S)-5,6-dihydroxy-2-methylamino-1,2,3,4-tetrahydro-naphthalene hydrochloride (CHF-1024) displays cardioprotection in postischemic ventricular dysfunction of the rat heart.

To analyze the protective effects of the aminotetraline derivative (+/-)-(R,S)-5,6-dihydroxy-2-methylamino-1,2,3,4-tetrahydro-naphthalene hydrochloride (CHF-1024), a compound endowed with DA2-dopaminergic/alpha2-adrenergic receptor agonistic activity, in myocardial ischemia/reperfusion damage. A model of isolated and perfused (15 ml/min) electrically driven (300 beats/min) rat heart subjected to global ischemia (1 ml/min for 20 min) and reperfusion (15 ml/min for 30 min) was followed. Cardiac mechanics changes were evaluated together with biochemical markers of cardiac ischemia in perfusate and tissue tumor necrosis factor-alpha (TNF-alpha). CHF-1024, perfused through the heart for 15 min before ischemia at different molar concentrations (1-100 nM), significantly improved left ventricle developed pressure during reperfusion, and normalized left ventricular end-diastolic pressure and coronary perfusion pressure. This anti-ischemic effect of CHF-1024 was associated to a decrease in creatine kinase and lactate dehydrogenase, both released during heart reperfusion. These events were concomitant with maintenance of a higher production of 6-keto-prostaglandin F1alpha The ability of CHF-1024 to improve postischemic ventricular dysfunction was correlated with a dose-dependent inhibition of the release of both norepinephrine (NE), from sympathetic nerve endings, and TNF-alpha from cardiac tissue. The effect of CHF-1024 on NE release was almost completely antagonized by specific antagonists of presynaptic inhibitory receptors domperidone and rauwolscine. The finding that this new aminotetraline derivative possesses anti-ischemic properties and limits NE release from cardiac nerve endings may bear some therapeutic potential in cardiovascular diseases.

Animals↗
PubMed2004

BL-1249 [(5,6,7,8-tetrahydro-naphthalen-1-yl)-[2-(1H-tetrazol-5-yl)-phenyl]-amine]: a putative potassium channel opener with bladder-relaxant properties.

BL-1249 [(5,6,7,8-tetrahydro-naphthalen-1-yl)-[2-(1H-tetrazol-5-yl)-phenyl]-amine] produced a concentration-dependent membrane hyperpolarization of cultured human bladder myocytes, assessed as either a reduction in fluorescence of the voltage-sensitive dye bis-(1,2-dibutylbarbituric acid)trimethine oxonol (EC50 = 1.26 +/- 0.6 microM) or by direct electrophysiological measurement (EC50 = 1.49 +/- 0.08 microM). BL-1249 also produced a membrane hyperpolarization of acutely dissociated rat bladder myocytes. Voltage-clamp studies in human bladder cells revealed that BL-1249 activated an instantaneous, noninactivating current that reversed near E(K). The BL-1249-evoked outward K+ current was insensitive to blockade by glyburide, tetraethylammonium, iberiotoxin, 4-aminopyridine, apamin, or Mg2+. However, the current was inhibited by extracellular Ba2+ (10 mM). In in vitro organ bath experiments, BL-1249 produced a concentration-dependent relaxation of 30 mM KCl-induced contractions in rat bladder strips (EC50 = 1.12 +/- 0.37 microM), yet had no effect on aortic strips up to the highest concentration tested (10 microM). The bladder relaxation produced by BL-1249 was partially blocked by Ba2+ (1 and 10 mM) but not by apamin, iberiotoxin, 4-aminopyridine, glyburide, or tetraethylammonium. In an anesthetized rat model, BL-1249 (1 mg/kg i.v.) decreased the number of isovolumic contractions, without significantly affecting blood pressure. Thus, BL-1249 behaves as a potassium channel activator that exhibits bladder versus vascular selectivity both in vitro and in vivo. A survey of potassium channels exhibiting sensitivity to extracellular Ba2+ at millimolar concentration revealed that the expression of the K2P2.1 (TREK-1) channel was relatively high in human bladder cells versus human aortic cells, suggesting this channel as a possible candidate target for BL-1249.

Anesthesia↗
PubMed2006

Antitumor activity of the retinoid-related molecules (E)-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid (ST1926) and 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) in F9 teratocarcinoma: Role of retinoic acid receptor gamma and retinoid-independent pathways.

The retinoid-related molecules (RRMs) ST1926 [(E)-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid] and CD437 (6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid) are promising anticancer agents. We compared the retinoic acid receptor (RAR) trans-activating properties of the two RRMs and all-trans-retinoic acid (ATRA). ST1926 and CD437 are better RARgamma agonists than ATRA. We used three teratocarcinoma cell lines to evaluate the significance of RARgamma in the activity of RRMs: F9-wild type (WT); F9gamma-/-, lacking the RARgamma gene; F9gamma51, aF9gamma-/-derivative, complemented for the RARgamma deficit. Similar to ATRA, ST1926 and CD437 activate cytodifferentiation only in F9-WT cells. Unlike ATRA, ST1926 and CD437 arrest cells in the G2/M phase of the cell cycle and induce apoptosis in all F9 cell lines. Our data indicate that RARgamma and the classic retinoid pathway are not relevant for the antiproliferative and apoptotic activities of RRMs in vitro. Increases in cytosolic calcium are fundamental for apoptosis, in that intracellular calcium chelators abrogate the process. Comparison of the gene expression profiles associated with ST1926 and ATRA in F9-WT and F9gamma-/-indicates that the RRM activates a conspicuous nonretinoid response in addition to the classic and RAR-dependent pathway. The pattern of genes regulated by ST1926 selectively, in a RARgamma-independent manner, provides novel insights into the possible molecular determinants underlying the activity of RRMs in vitro. Furthermore, it suggests that RARgamma-dependent responses are relevant to the activity of RRMs in vivo. Indeed, the receptor hinders the antitumor activity in vivo, in that both syngeneic and immunosuppressed SCID mice bearing F9gamma-/- tumors have increased life spans after treatment with ST1926 and CD437 relative to their F9-WT counterparts.

Adamantane↗
PubMed1996

Naphthalene sulfonate polymers with CD4-blocking and anti-human immunodeficiency virus type 1 activities.

PIC 024-4 and PRO 2000 are naphthalene sulfonate polymers that bind to CD4 with nanomolar affinity and block binding of gp120. Both have activity against human immunodeficiency virus type 1 in H9 cells, peripheral blood mononuclear cells, and primary monocyte/macrophages, are synergistic with zidovudine, and do not inhibit tetanus toxoid-stimulated T-cell proliferation at anti-human immunodeficiency virus type 1 concentrations.

Animals↗
PubMed1993

Polymerase chain reaction amplification of naphthalene-catabolic and 16S rRNA gene sequences from indigenous sediment bacteria.

We report the amplification of bacterial genes from uninoculated surface and subsurface sediments by the polymerase chain reaction (PCR). PCR amplification of indigenous bacterial 16S ribosomal DNA genes was unsuccessful when subsurface sediment containing approximately 10(7) cells.g-1 was added directly to a PCR mixture. However, when 10 mg of sediment was inoculated with approximately 10(5) cells of Pseudomonas putida G7, the nahAc naphthalene dioxygenase gene characteristic of the P. putida G7 NAH7 plasmid was detected by PCR amplification. Southern blotting of the PCR amplification product improved sensitivity to 10(3) to 10(4) cells from samples inoculated with P. putida G7, but controls with no sediment added showed that the PCR was partially inhibited by the sediments. Lysozyme-sodium dodecyl sulfate-freeze-thaw DNA extraction was combined with gel electrophoretic partial purification in the presence of polyvinylpyrrolidone to render DNA from indigenous bacteria in surface or subsurface sediment samples amplifiable by PCR using eubacterial 16S ribosomal DNA primers. The nahAc gene could also be amplified from indigenous bacteria by using nahAc-specific primers when PCR conditions were modified by increasing Taq and primer concentrations. Restriction digests of the nahAc amplification products from surface and subsurface sediments revealed polymorphism relative to P. putida G7. The procedures for DNA extraction, purification, and PCR amplification described here demonstrate that the PCR is a potentially useful tool in studies of function- and taxon-specific DNA from indigenous microbial communities in sediment and groundwater environments.

Base Sequence↗
PubMed1994

Regiospecific and stereoselective hydroxylation of 1-indanone and 2-indanone by naphthalene dioxygenase and toluene dioxygenase.

The biotransformation of 1-indanone and 2-indanone to hydroxyindanones was examined with bacterial strains expressing naphthalene dioxygenase (NDO) and toluene dioxygenase (TDO) as well as with purified enzyme components. Pseudomonas sp. strain 9816/11 cells, expressing NDO, oxidized 1-indanone to a mixture of 3-hydroxy-1-indanone (91%) and 2-hydroxy-1-indanone (9%). The (R)-3-hydroxy-1-indanone was formed in 62% enantiomeric excess (ee) (R:S, 81:19), while the 2-hydroxy-1-indanone was racemic. The same cells also formed 2-hydroxy-1-indanone from 2-indanone. Purified NDO components oxidized 1-indanone and 2-indanone to the same products produced by strain 9816/11. P. putida F39/D cells, expressing TDO, oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 76% ee (R:S, 12:88) but did not oxidize 1-indanone efficiently. Purified TDO components also oxidized 2-indanone to (S)-2-hydroxy-1-indanone of 90% ee (R:S, 5:95) and failed to oxidize 1-indanone. Oxidation of 1- and 2-indanone in the presence of [18O]oxygen indicated that the hydroxyindanones were formed by the incorporation of a single atom of molecular oxygen (monooxygenation) rather than by the dioxygenation of enol tautomers of the ketone substrates. As alternatives to chemical synthesis, these biotransformations represent direct routes to 3-hydroxy-1-indanone and 2-hydroxy-1-indanone as the major products from 1-indanone and 2-indanone, respectively.

Biotransformation↗
PubMed1996

Toluene and ethylbenzene oxidation by purified naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

Purified naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized toluene to benzyl alcohol and benzaldehyde by reactions involving benzylic monooxygenation and dioxygen-dependent alcohol oxidation, respectively. Xylene and nitrotoluene isomers were also oxidized to substituted benzyl alcohol and benzaldehyde derivatives. NDO oxidized ethylbenzene sequentially through (S)-1-phenethyl alcohol (77% enantiomeric excess) and acetophenone to 2-hydroxyacetophenone. In addition, NDO also oxidized ethylbenzene through styrene to (R)-1-phenyl-1,2-ethanediol (74% enantiomeric excess) by reactions involving desaturation and dihydroxylation, respectively. Isotope experiments with 18O2, H2 18O, and D2O suggest that 1-phenethyl alcohol is oxidized to acetophenone by a minor reaction involving desaturation followed by tautomerization. The major reaction in the conversion of 1-phenethyl alcohol and benzyl alcohol to acetophenone and benzaldehyde, respectively, probably involves monohydroxylation to form a gem-diol intermediate which stereospecifically loses the incoming hydroxyl group to leave the carbonyl product. These results are compared with similar reactions catalyzed by cytochrome P-450.

Benzene Derivatives↗