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At least 109 records · Page 6Linked to original sources
PubMed2004

catena-Poly[[di-mu-benzoato-kappa4O:O'-disilver(I)]-mu-N,N'-bis(2-fluorobenzylidene)butane-1,4-diamine-kappa2N:N'].

The title complex, [Ag(2)(C(7)H(5)O(2))(2)(C(18)H(18)F(2)N(2))](n), is a dinuclear silver(I) compound with one inversion centre between pairs of Ag atoms and another at the mid-point of the central C-C bond in the butane-1,4-diamine moiety. Each of the smallest repeat units consists of two silver(I) cations, two benzoate anions and one N,N'-bis(2-fluorobenzylidene)butane-1,4-diamine Schiff base ligand. Each Ag(I) ion is three-coordinated in a trigonal configuration by two O atoms from two benzoate anions and one N atom from a Schiff base ligand. The di-mu-benzoato-disilver(I) moieties are linked by the bridging Schiff base ligand, giving zigzag polymeric chains with an [-Ag...Ag-N-C-C-C-C-N-](n) backbone running along the b axis.

Journal Article↗
PubMed2004

Butane-1,4-diamine zinc(II) hydrogen phosphite.

The title compound, poly[zinc(II)-mu-butane-1,4-diamine-mu-(hydrogen phosphito)] (C(4)H(12)N(2))(0.5)[ZnHPO(3)], is a hybrid organic-inorganic solid built up from 1,4-diaminobutane molecules, Zn(2+) cations (coordinated by three O atoms and one N atom) and HPO(3)(2-) hydrogen phosphite groups. The organic species bonds to the Zn atom as an unprotonated ligand, resulting in it acting as a bridge between infinite ZnHPO(3) layers, which propagate in (100). The complete butane-1,4-diamine species is generated from a H(2)N(CH(2))(2)- half molecule by inversion symmetry. The zincophosphite sheets contain polyhedral four- and eight-membered rings in a 4.8(2) topology.

Journal Article↗
PubMed2005

A novel two-dimensional network cadmium(II) coordination polymer containing one 1,4-bis(1,2,4-triazol-1-yl)butane and double dicyanamide bridges.

In the crystal structure of the title complex, poly[mu-1,4-bis(1,2,4-triazol-1-yl)butane-di-mu-1,5-dicyanamido-cadmium(II)], [Cd(C2N3)2(C8H12N6)]n or [Cd(dca)2(btb)]n, where dca is dicyanamide and btb is 1,4-bis(1,2,4-triazol-1-yl)butane, each Cd(II) atom occupies a center of symmetry and is in a six-coordinated distorted octahedral environment. Four N atoms from four dca ligands fill the equatorial positions, and two N atoms from two btb ligands occupy the axial positions. The dca ligands adopt an end-to-end coordination mode and link the Cd(II) atoms to form a 12-membered Cd(dca)2Cd ring, and neighboring rings extend along the b axis to form a [Cd(dca)2]n chain. The btb ligands, acting as bridging bidentate ligands, link the Cd(II) atoms of adjacent one-dimensional [Cd(dca)2]n chains, forming a rhombic two-dimensional network.

Journal Article↗
PubMed2006

Two-dimensional square-grid frameworks formed by self-associating copper(II) complexes with 1-(3-pyridyl)- and 1-(4-pyridyl)-substituted butane-1,3-diones.

In bis[1-(3-pyridyl)butane-1,3-dionato]copper(II) (the Cu atom occupies a centre of inversion), [Cu(C9H8NO2)2], (I), and bis[1-(4-pyridyl)butane-1,3-dionato]copper(II) methanol solvate, [Cu(C9H8NO2)2].CH3OH, (II), the O,O'-chelating diketonate ligands support square-planar coordination of the metal ions [Cu-O=1.948 (1)-1.965 (1) A]. Weaker Cu...N interactions [2.405 (2)-2.499 (2) A], at both axial sides, occur between symmetry-related bis(1-pyridylbutane-1,3-dionato)copper(II) molecules. This causes their self-organization into two-dimensional square-grid frameworks, with uniform [6.48 A for (I)] or alternating [4.72 and 6.66 A for (II)] interlayer separations. Guest methanol molecules in (II) reside between the distal layers and form weak hydrogen bonds to coordinated O atoms [O...O=3.018 (4) A].

Journal Article↗
PubMed1993

32P-postlabelling analysis of DNA-adducts formed by 4-(N-carbethoxy-N-nitrosamino)-(3-pyridyl)-1-butanone and 4-oxo-4-(3-pyridyl)- butanal.

The tobacco-specific nitrosamine, 4-(N-nitrosomethylamino)-1-(3-pyridyl)- 1-butanone (NNK) can be activated to DNA-binding species by two pathways: methylene hydroxylation leads to an equimolar formation of methyldiazohydroxide and 4-oxo-4-(3-pyridyl)-butanal followed by DNA methylation, while methyl hydroxylation leads to DNA pyridyloxobutylation via the 4-(3-pyridyl)-4-oxobutyldiazohydroxide (Hecht et al., 1988; Spratt et al., 1989). We report here that the ketoaldehyde, 4-oxo-4-(3-pyridyl)-butanal, as well as 4-(N-carbethoxy-N-nitrosamino)-1-(3- pyridyl)-1-butanone (NNC), a model compound for pyridyloxobutylation, form DNA adducts in vitro, as detected by 32P-postlabelling assays. The two major adduct spots of both compounds were chromatographically indistinguishable, suggesting structurally similar DNA adducts.

Animals↗
PubMed2004

Enantiomerically pure [1, 2-diamino-1-(4-fluorophenyl)butane]platinum(II) complexes: synthesis and antitumor activity against MCF-7 and MDA-MB 231 breast cancer and LnCaP/FGC prostate cancer cell lines.

Enantiomerically pure 1, 2-diamino-1-(4-fluorophenyl)butanes were synthesized by stereoselective procedures. The enantiomeric purity was determined by (1)H NMR spectroscopy after derivatization with (1R)-myrtenal. For the coordination to platinum, the diamines were reacted with K(2)PtI(4). Reaction with Ag(2)SO(4) yielded the respective sulfatoplatinum(II) complexes, which were converted into the dichloroplatinum(II) complexes by treatment with 2 N HCl. The influence of the configuration and the kind of leaving group on the antitumor activity was studied on the MCF-7 and MDA-MB 231 breast cancer cell lines, as well as on the LnCaP/FGC prostate cancer cell line. It was demonstrated that the dichloroplatinum(II) complexes were more active than the respective diiodoplatinum(II) derivatives. Conversion into the sulfatoplatinum(II) complexes further enhanced the antiproliferative effects. The configuration determined the antitumor effects, dependent on the cell line used: MCF-7: (R, R) > (S, S) > (R, S) > (S, R); MDA-MB 231: (S, S) > (R, R) > (R, S) = (S, R); LnCaP/FGC: (S, S) > (R, R) > (R, S) > (S, R).

Antineoplastic Agents↗
PubMed2003

A definitive synthesis of D-myo-inositol 1,4,5,6-tetrakisphosphate and its enantiomer D-myo-inositol 3,4,5,6-tetrakisphosphate from a novel butane-2,3-diacetal-protected inositol.

New and rapid syntheses of the enantiomeric intracellular signalling molecules d-myo-inositol 1,4,5,6-tetrakisphosphate (1 a) and D-myo-inositol 3,4,5,6-tetrakisphosphate (1 b) are described. The synthetic strategy employs the novel butane-2,3-diacetal-protected (BDA-protected) myo-inositol (+/-)-3 ab, directly accessible from myo-inositol on a large scale, and an optical resolution with diastereoisomeric (R)-(-)-acetylmandelate esters. The X-ray crystal structure of (+/-)-4, an unusual side product of acid-catalysed reaction of myo-inositol with butanedione is also presented, and the absolute configurations of 1 a and 1 b are definitively assigned by conversion of key precursors into (+)-bornesitol and L-iditol hexaacetate, respectively. Biological activity of synthetic 1 b was confirmed in comparison with the natural polyphosphate.

Acetals↗
PubMed1985

Burn injuries from portable butane camping stoves.

Admissions to the Wessex Regional Burns Unit for injuries sustained whilst using portable butane camping stoves are reviewed. There have been 31 cases of such injuries in the past 10 years with one fatal outcome. Most accidents occurred while changing the canister. The number of accidents occurring suggests that these stoves must be regarded as intrinsically very hazardous and that a greater awareness of the dangers by users is necessary.

Blast Injuries↗
PubMed2005

Uncatalyzed synthesis, thermal and mechanical properties of polyurethanes based on poly(epsilon-caprolactone) and 1,4-butane diisocyanate with uniform hard segment.

Polyurethanes based on poly(epsilon-caprolactone) (PCL) (750-2800 g/mol) and 1,4-butane diisocyanate (BDI) with different soft segment lengths and constant uniform hard segment length were synthesized in absence of catalysts for the production of a degradable meniscus scaffold. First the polyesterdiols were endcapped with BDI yielding a macrodiisocyanate with a minimal amount of side reactions and a functionality of 2.0. Subsequently, the macrodiisocyanates were extended with 1,4-butanediol in order to obtain the corresponding polyurethane. The polyurethanes had molecular weights between 78 and 160 kg/mol. Above molar masses of 1900 g/mol of the polyesterdiol crystalline PCL was found while the hard segment showed an increase in melting point from 78 to 122 degrees C with increasing hard segment content. It was estimated that the percentage crystallinity of the hard segment varied between 92 and 26%. The Young's modulus varied between 30 and 264 MPa, the strain at break varied between 870 and 1200% and tear strengths varied between 97 and 237 kJ/m2.

Absorbable Implants↗
PubMed2004

Molecular docking and 3D QSAR studies on 1-amino-2-phenyl-4-(piperidin-1-yl)-butanes based on the structural modeling of human CCR5 receptor.

In the present study, we have used an approach combining protein structure modeling, molecular dynamics (MD) simulation, automated docking, and 3D QSAR analyses to investigate the detailed interactions of CCR5 with their antagonists. Homology modeling and MD simulation were used to build the 3D model of CCR5 receptor based on the high-resolution X-ray structure of bovine rhodopsin. A series of 64 CCR5 antagonists, 1-amino-2-phenyl-4-(piperidin-1-yl)-butanes, were docked into the putative binding site of the 3D model of CCR5 using the docking method, and the probable interaction model between CCR5 and the antagonists were obtained. The predicted binding affinities of the antagonists to CCR5 correlate well with the antagonist activities, and the interaction model could be used to explain many mutagenesis results. All these indicate that the 3D model of antagonist-CCR5 interaction is reliable. Based on the binding conformations and their alignment inside the binding pocket of CCR5, three-dimensional structure-activity relationship (3D QSAR) analyses were performed on these antagonists using comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) methods. Both CoMFA and CoMSIA provide statistically valid models with good correlation and predictive power. The q(2)(r(cross)(2)) values are 0.568 and 0.587 for CoMFA and CoMSIA, respectively. The predictive ability of these models was validated by six compounds that were not included in the training set. Mapping these models back to the topology of the active site of CCR5 leads to a better understanding of antagonist-CCR5 interaction. These results suggest that the 3D model of CCR5 can be used in structure-based drug design and the 3D QSAR models provide clear guidelines and accurate activity predictions for novel antagonist design.

Binding Sites↗
PubMed2005

Steric and electronic effects on the conformations of n-butane derivatives with trichlorosilyl, silyl and trichloromethyl groups.

The molecular structure and conformation of 1,1,1,4,4,4-hexachloro-1,4-disilabutane in the gas-phase have been determined by electron diffraction and computational methods. The lowest-energy conformation has the trichlorosilyl groups anti to one another. The gauche conformation also has a shallow potential minimum, but lies about 19 kJ mol-1 above the anti form. Calculations on related butane derivatives, in which terminal methyl groups have been replaced by CCl3, SiH3 and SiCl3 groups, reveal that the conformational preferences are primarily caused by steric interactions between the terminal groups, and that it is the presence of chlorine atoms that destabilises gauche conformations. The electronegativity of the chlorine atoms has only small effects, mainly limited to the SiCl bond lengths.

Butanes↗
PubMed1984

Butane firebreathing in adolescents: a potentially dangerous practice.

Firebreathing is sometimes seen in magic acts. This is, potentially, a very dangerous practice without the proper precautions. What follows is a report of an adolescent who became a habitual butane firebreather after imitating this act. He developed hemorrhagic esophagitis and gastritis. The type of adolescent who may experiment with dangerous practices is discussed.

Adolescent↗
PubMed2001

Antagonists of the human CCR5 receptor as anti-HIV-1 agents. Part 2: structure-activity relationships for substituted 2-Aryl-1-[N-(methyl)-N-(phenylsulfonyl)amino]-4-(piperidin-1-yl)butanes.

(2S)-2-(3,4-Dichlorophenyl)-1-[N-(methyl)-N-(phenylsulfonyl)amino]-4-[spiro(2,3-dihydrobenzthiophene-3,4'-piperidin-1'-yl)]butane S-oxide (3) has been identified as a potent CCR5 antagonist lead structure having an IC50 = 35 nM. Herein, we describe the structure-activity relationship studies directed toward the requirement for and optimization of the C-2 phenyl fragment. The phenyl was found to be important for CCR5 antagonism and substitution was limited to small moieties at the 3-position (13 and 16: X= H, 3-F, 3-Cl, 3-Me).

Animals↗
PubMed2001

Antagonists of the human CCR5 receptor as anti-HIV-1 agents. Part 3: a proposed pharmacophore model for 1-[N-(methyl)-N-(phenylsulfonyl)amino]-2-(phenyl)-4-[4-(substituted)piperidin-1-yl]butanes.

Structure-activity relationship studies directed toward the optimization of (2S)-2-(3-chlorophenyl)-1-[N-(methyl)-N-(phenylsulfonyl)amino]-4-[4-(substituted)piperidin-1-yl]butanes as CCR5 antagonists resulted in the synthesis of the spiro-indanone derivative 8c (IC50=5 nM). These and previous results are summarized in a proposed pharmacophore model for this class of CCR5 antagonist.

Animals↗
PubMed2001

Antagonists of the human CCR5 receptor as anti-HIV-1 agents. Part 4: synthesis and structure-activity relationships for 1-[N-(methyl)-N-(phenylsulfonyl)amino]-2-(phenyl)-4-(4-(N-(alkyl)-N-(benzyloxycarbonyl)amino)piperidin-1-yl)butanes.

(2S)-2-(3-Chlorophenyl)-1-[N-(methyl)-N-(phenylsulfonyl)amino]-4-[spiro(2,3-dihydrobenzthiophene-3,4'-piperidin-1'-yl)]butane S-oxide (1b) has been identified as a potent CCR5 antagonist having an IC50=10 nM. Herein, structure-activity relationship studies of non-spiro piperidines are described, which led to the discovery of 4-(N-(alkyl)-N-(benzyloxycarbonyl)amino)piperidine derivatives (3-5) as potent CCR5 antagonists.

Animals↗
PubMed2005

Synthesis of some new 1,3/ or 1,4-bis(glucopyranosyl-1,2,4-triazol-5-ylthio)propanes/ or butanes as potential antimicrobial agents.

Glucosidation of the appropriate 1,3 or 1,4-bis(4-amino or arylideneamino-2,4-dihydro-3-thioxo-3H-1,2,4-triazol-5-ylthio)propanes or butanes with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide followed by chromatographic separation gave the corresponding N-, S-, and N,S-bis(glucosides). Chemical transformation leading to new functionalities has been achieved. Antimicrobial screening of 10 selected compounds resulted in their activity against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli.

Anti-Infective Agents↗
PubMed1997

Complications following butane inhalation and flash fire.

Solvent inhalation is a well-documented form of drug abuse that can cause euphoria and hallucinations. Sudden death involving a volatile substance is most commonly caused by cardiac arrythmias, asphyxia, direct drug effects, and trauma. The victim in this paper suffered superficial partial thickness (12% total body surface area) burns from a flash fire that occurred when lighting a match after inhaling butane in an enclosed vehicle. The victim was admitted to the hospital for 2 days of observation but did not develop any respiratory symptoms under 2 days following her release. The victim died during her readmission, 9 days after the flash fire. Postmortem examination showed extensive epithelial injury from the upper airway and trachea to the terminal bronchioles, most likely due in part to both the initial inhalation injury and the resulting adult respiratory distress syndrome (ARDS) and staphylococcal infection. Many victims with superficial burn injuries may not seek medical attention owing to either embarrassment or fear of legal prosecution. Even those who do seek medical assistance may not reveal solvent abuse as the cause of their injuries. It is possible that delayed death may occur at home following volatile substance abuse but may remain unrecognized even with a thorough scene investigation.

Adolescent↗