111 research outputs found
1H NMR Study of the Enantioselective Binding of λ- and Δ-[Ru(bpy)2(m-bpy-GHK)]Cl2 to the Deoxynucleotide Duplex d(5'-C1G2C3G4A5A6T7T8C9G10C11G12-3')2
The interaction of the diastereomeric complexes Λ- and Δ - [Ru(bpy)2(m - GHK)]Cl2, (GHK = glycine-histidine-lysine) to the deoxynucleotide duplex d(5'-CGCGAATTCGCG-3')2 was studied by means of 1H NMR spectroscopy. The diastereomers interact with the oligonucleotide duplex differently. The Δ - [Ru(bpy)2 (m - GHK)]Cl2 is characterized by major groove binding close to the central part of the oligonucleotide, with both the peptide and the bipyridine ligand of the complex involved in the binding. The λ - [Ru(bpy)2 (m - bpy - GHK)]C2 binds loosely, approaching the helix from the minor groove. The NMR analysis shows that the peptide (GHK) binding has a determinative role in the interactions of both diastereomers with the oligonucleotide
Interpenetrated networks from a novel nanometer-sized pseudopeptidic ligand, bridging water, and transition metal ions with CdSO4 topology.
The combination of a new pseudopeptidic ligand, transition
metal ions, and bridging water molecules results in the
formation of [M(m-TBG)(m-H2O)(H2O)2]?2H2O (M: Cu, Co
and H2TBG: terephthaloylbisglycine); both compounds show
rare two-fold interpenetrated three-dimensional cds-nets and
reversible loss of coordinated and lattice water molecule
Communication: Synthesis of a Novel Triphenyltin(IV) Derivative of 2- Mercaptonicotinic Acid with Potent Cytotoxicity in vitro
A novel triphenyltin(IV) derivative of 2-mercaptonicotinic acid (H2mna) of formula
{[(C6H5)3Sn]2(mna).[(CH3)2CO]} (1) has been synthesized and characterized by elemental analysis and 1H, 13C-NMR, and FT-IR spectroscopic techniques. The crystal structure of complex (1) has been determined by single crystal X-ray diffraction analysis at 173(1) K. Compound (1) contains two triphenyltin moieties linked
by a doubly de-protonated 2,mercaptonicotinic acid (H>2mna). It is an example of a pentacoordinated
Ph3SnXY system with an axial-equatorial arrangement of the phenyl groups at Sn(1). Compound (1), exhibits
potent, in vitro, cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat,
polycyclic aromatic hydrocarbons (PAH, benzo[a]pyrene) carcinogenesis
Bacteremia in Lung Transplant Recipients in the Current Era
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71409/1/j.1600-6143.2006.01565.x.pd
S-alkyl and S-alkylaryl cysteine complexes with platinum(II) and their interactions with nucleosides
The reactions of K2PtCl4 with the aminoacids, S-methyl-L-cysteine, S-ethyl-L-cysteine, S-benzyl-L-cysteine, S-para-nitro-benzyl-L-cysteine, S-diphenyl-methyl-L-cysteine, S-tribenzyl-L-cysteine and S-4′,4′-dimethoxy-diphenylmethyl-L-cysteine were studied in neutral or acidic aqueous solutions. Complexes of the formulae PtLCl2, [PtL2]Cl2 and Pt(L-H+)2, where L = aminoacid, were isolated in the solid state and their structures investigated with elemental analysis, conductivity measurements, IR, 1H NMR and 13CNMR spectra. The results show that the coordination sites of Pt(II) with the amino-acids are the N and S atoms, producing two diastereoisomers around the chiral sulphur atom, which were identified in the 1H NMR and 13CNMR spectra. The complexes PtLCl2 further react with the nucleosides guanosine and inosine. The complexes [PtL(nucl)2]Cl2 were isolated from these reactions and studied with the same methods. They showed a PtN7 bonding with the nucleosides and retained the N, S bondings with the aminoacids. As a result of the higher trans influence of S than N, the nucleoside molecule coordinated to the metal through N7 and trans to S has a weaker bond strength than the other, as it is revealed from the 1H NMR and 13C NMR spectra of these complexes. © 1985
S-alkyl and S-alkylaryl cysteine complexes with platinum(II) and their interactions with nucleosides
The reactions of K2PtCl4 with the aminoacids, S-methyl-L-cysteine, S-ethyl-L-cysteine, S-benzyl-L-cysteine, S-para-nitro-benzyl-L-cysteine, S-diphenyl-methyl-L-cysteine, S-tribenzyl-L-cysteine and S-4′,4′-dimethoxy-diphenylmethyl-L-cysteine were studied in neutral or acidic aqueous solutions. Complexes of the formulae PtLCl2, [PtL2]Cl2 and Pt(L-H+)2, where L = aminoacid, were isolated in the solid state and their structures investigated with elemental analysis, conductivity measurements, IR, 1H NMR and 13CNMR spectra. The results show that the coordination sites of Pt(II) with the amino-acids are the N and S atoms, producing two diastereoisomers around the chiral sulphur atom, which were identified in the 1H NMR and 13CNMR spectra. The complexes PtLCl2 further react with the nucleosides guanosine and inosine. The complexes [PtL(nucl)2]Cl2 were isolated from these reactions and studied with the same methods. They showed a PtN7 bonding with the nucleosides and retained the N, S bondings with the aminoacids. As a result of the higher trans influence of S than N, the nucleoside molecule coordinated to the metal through N7 and trans to S has a weaker bond strength than the other, as it is revealed from the 1H NMR and 13C NMR spectra of these complexes. © 1985
Reactions of hydrogenated thiamine derivatives with K2[MX4], where M is PdII or PtII and X is Cl or Br
The reactions of K2[MX4], where M is PdII or PtII and X is Cl or Br, with the hydrogenated thiamine derivatives L, 3-[(4′-amino-2′-methyl-5′-pyrimidinyl)methyl]-5-(β- hydroxyethyl)-4-methylthiazolidine (L1), 3-[(4′-amino-2′-methyl-5′-pyrimidinyl)methyl]-5-(β- hydroxyethyl)-4-methylthiazoline (L2), 3-[(4′-amino-2′-methyl-5′-pyrimidinyl)methyl]-4-methyl-5- (β-monophosphatoethyl)thiazolidine (L3), 3-[(4′-amino-2′-methyl-5′;-pyrimidinyl)methyl]-4-methyl-5- (β-pyrophosphatoethyl)thiazolidine (L4) and their deuteriated derivatives, have been studied in aqueous solutions at pH ca. 1 and 5.5. The products, [ML2X2].2HX and [ML2X2], have been isolated from these studies and characterized by elemental analyses, conductivity measurements, pH-metric titrations, i.r., 1H n.m.r., and 13C n.m.r. spectra. A complete assignment of the 1H and 13C n.m.r. spectral resonances is presented for both the ligands and the complexes. The results show that the ligands are protonated primarily at the N1′ atom of the pyrimidine moiety, while the metallation site is either the N3 or the S atom of the thiazoline or thiazolidine ring
A study of the reactions of cysteinatomethylester platinum(II)-μ-dichloro cysteinatomethylester platinum(II) with nucleosides
The reactions of the dinuclear complex cysteinatomethylester platinum(II)-μ-dichlorocysteinatomethylester platinum(II),[Pt(O-MeCys)Cl]2, with nucleosides have been studied in aqueous solutions. The isolated complexes correspond to the general formulae [Pt(O-MeCys)(nucl)Cl], where nucl = cytidine (cyd), inosine (ino),guanosine (guo), adenosine (ado), tri- and tetraacetyladenosine (trado, tetado) and triacetylinosine and guanosine (trino,trguo). The complexes were characterized by elemental analyses, conductivity measurements, IR, 1H NMR and 13C NMR spectra. The results indicate that the purine bases coordinate through both N(7) and N(1) with Pt(II), whenenver these are available, while cytidine does so through N(3). The PtN bond in this case is found weaker as compared to other similar bonds, due to the high trans influence of the opposite PtS bond. © 1980
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