Search results for "Pyridine"
showing 10 items of 2516 documents
CCDC 907992: Experimental Crystal Structure Determination
2014
Related Article: Inguna Goba, Baiba Turovska, Sergey Belyakov, Edvards Liepinsh|2014|J.Mol.Struct.|1074|549|doi:10.1016/j.molstruc.2014.06.044
CCDC 885313: Experimental Crystal Structure Determination
2013
Related Article: I.Goba,B.Turovska,S.Belyakov,E.Liepinsh|2013|Khim.Get.Soedin.,SSSR||778|
Heterocyclic and Phenyl Double-Bond-Locked Combretastatin Analogues Possessing Potent Apoptosis-inducing activity in HL60 and in MDR Cell lines
2005
Two new series of combretastatin (CA-4) analogues have been prepared. The alkenyl motif of CA-4 was replaced either by a five-membered heterocyclic (isoxazoline or isoxazole) or by a six-membered ring (pyridine or benzene). The new compounds have been evaluated for their effects on tubulin assembly and for cytotoxic and apoptotic activities. Five compounds (18b, 20a, 21a, 34b, and 35b) demonstrated an attractive profile of cytotoxicity (IC501 microM) and apoptosis-inducing activity but poor antitubulin activity. The isoxazoline derivatives 18b, 20a, and 21a, demonstrated potent apoptotic activity different from that of natural CA-4. Their ability to block most cells in the G2 phase suggests…
Intermolecular binding modes in a novel [1 + 1] condensation 1H-pyrazole azamacrocycle: a solution and solid state study with evidence for CO2 fixati…
2013
The synthesis of a novel cyclophane (L1) consisting of a 1H-pyrazole moiety linked through methylene groups to a 1,5,9,13-tetraazadecane chain is described. As far as we know, this is one of the first reported syntheses of a [1 + 1] condensation 1H-pyrazole azamacrocyclic ligand. The crystal structures of the complexes [Cu2(H(H(-1)L1))(H(-1)L1)](ClO4)3·3.75H2O (1) and ([Cu2(H(H(-1)L1))(0.5)(H(-1)L1)(1.5)]2(ClO4)3Br2·4.2H2O (2) show that Cu(2+) coordination leads to formation of 2:2 Cu(2+):L dinuclear dimeric complexes in which the 1H-pyrazole units lose a proton behaving as bis(monodentate) bridging ligands. Unlike previously reported complexes of [2 + 2] pyrazole azamacrocycles, the pyrazo…
Coordination Polymers Containing Manganese(II)-Azido Layers Connected by Dipyridyl-tetrazine and 4,4′-Azobis(pyridine) Linkers
2013
Two new polynuclear manganese(II) complexes [Mn(dptz)(N(3))(2)](n) (1) and [Mn(azpy)(N(3))(2)](n) (2) (where dptz = dipyridyl-tetrazine and azpy = 4,4'-azobis(pyridine)) have been synthesized by self-assembly of the ligand azide, together with dptz and azpy as secondary spacers. The compounds are characterized by single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that in complex 1, which is the first reported Mn(II) complex with the ligand dptz, two μ(1,3) bridging azides connect neighboring manganese ions in a zigzag manner to generate a neutral two-dimensional (2D) sheet which is further connected by the dptz ligands to…
From Five- to Six-Membered Rings: 3,4-Diarylquinolinone as Lead for Novel p38MAP Kinase Inhibitors
2007
In this study we describe the design, synthesis, and biological evaluation of 3-(4-fluorophenyl)-4-pyridin-4-ylquinoline-2(1H)-one (5) as a new inhibitor of MAPK with a p38alphaMAPK IC50 of 1.8 muM. By keeping the common vicinal pyridine/4-F-phenyl pharmacophore, such as in prototypical imidazole 20 or isoxazole 13 but in 5 connected to the six-membered quinoline core, we were particularly interested in comparing biological activity, details of molecular geometry, and different binding modes of these compounds. Compounds 20 and 13 were active both in the p38alpha- and JNK3-assay, whereas 5 was selective for p38alpha, with no JNK3 inhibition. By comparing the X-ray structures of the compound…
Ferromagnetic Cu(II)4, Co(II)4, and Ni(II)6 azido complexes derived from metal-assisted methanolysis of di-2,6-(2-pyridylcarbonyl)pyridine.
2009
Reaction of copper(II) perchlorate with di-2,6-(2-pyridylcarbonyl)pyridine (pyCOpyCOpy, dpcp) in the presence of sodium azide yields complex [Cu(4)(N(3))(2){pyC(OMe)(O)pyC(OMe)(O)py}(2)(MeOH)(2)](ClO(4)) x 2 MeOH (1 x 2 MeOH), which crystallizes in the monoclinic P2(1)/c space group. Similar reaction of cobalt(II) nitrate yields complex [Co(4)(N(3))(2)(NO(3))(2){pyC(OMe)(O)pyC(OMe)(O)py}(2)] x 0.5 MeOH (2 x 0.5 MeOH) which crystallizes in the monoclinic I2/m space group. Reaction of nickel(II) perchlorate yields complex [Ni(6)(CO(3))(N(3))(6){pyCOpyC(O)(OMe)py}(3)(MeOH)(2)(H(2)O)][Ni(6)(CO(3))(N(3))(6){pyCOpyC(O)(OMe)py}(3) (MeOH)(3)](ClO(4))(2) x 1.8 MeOH (3 x 1.8 MeOH), which crystallizes…
Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex
2010
The copper(II) complex of 3,5-bis(2'-pyridyl)-1,2,4-oxadiazole was synthesized and characterized. X-Ray crystallography revealed that the complex consists of a discrete [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) cation and two ClO(4)(-) anions. The Cu(II) coordination sphere has a distorted octahedral geometry and each ligand chelates the copper ion through the N(4) nitrogen of the oxadiazole ring and the nitrogen of one pyridine moiety. The coordinated water molecules are in cis position and each of them is H-bonded to the 5-pyridyl nitrogen of the oxadiazole ligand and to an oxygen of the perchlorate anion. Biological assays showed that, despite the free ligand not being …
A simple helical macrocyclic polyazapyridinophane as a stereoselective receptor of biologically important dicarboxylates under physiological conditio…
2007
The interaction of a synthetic enantiopure azamacrocyclic receptor (L) with biologically important chiral dicarboxylates (A, 1-7) has been studied by means of potentiometric titrations in 0.15 M NaCl aqueous solution in a wide pH range. This macrocycle forms strong complexes of the type [HnLA](n-2) (with n = 0-5). As a general trend, the binding is much tighter at basic or neutral pH than in acidic medium. Interestingly, nonprotected excitatory amino acids (Asp and Glu) are strongly bound even at acidic pH. Regarding selectivity, the receptor showed stereoselective binding toward those substrates bearing an H-bonding donor at Calpha, being S-selective in most of the cases, except for glutam…
Coordination Diversity in Mono- and Oligonuclear Copper(II) Complexes of Pyridine-2-Hydroxamic and Pyridine-2,6-Dihydroxamic Acids
2013
Solution and solid state studies on Cu(II) complexes of pyridine-2-hydroxamic acid (HPicHA) and pyridine-2,6-dihydroxamic acid (H2PyDHA) were carried out. The use of methanol/water solvent allowed us to investigate the Cu(II)-HPicHA equilibria under homogeneous conditions between pH 1 and 11. In agreement with ESI-MS indication, the potentiometric data fitted very well with the model usually reported for copper(II) complexes of α-aminohydroxamate complexes ([CuL](+), [Cu5(LH-1)4](2+), [CuL2], [CuL2H-1](-)), however with much higher stability of the 12-MC-4 species. A series of copper(II) complexes has been isolated in the solid state and characterized by a variety of spectroscopic methods, …