Search results for "Cyclam"
showing 10 items of 72 documents
1,8-Bis[3-(triethoxysilyl)propyl]-1,8-diazoniatricyclo[9.3.1.14,8]hexadecane diiodide
2009
The organic molecule of title compound, C30H66N4O6Si22+·2I−, is located around a centre of symmetry. The structure exhibits disorder of the triethoxy groups with the ratios 0.78 (1)/0.22 (1), 0.67 (1)/0.33 (1) and 0.58 (1)/0.42 (1).
Triterpene Saponins from Cyclamen trocopteranthum
2010
Two new triterpene saponins ( 1- 2) together with three known saponins, deglucocyclamin I ( 3), cyclamin ( 4), and mirabilin ( 5), were isolated from the tubers of Cyclamen trocopteranthum. They were elucidated as 3 beta- O-{4- O-[3-hydroxyl-3-methylglutaryl]- beta-D-xylopyranosyl-(1 --> 2)- beta-D-glucopyranosyl-(1 --> 4)-[ beta-D-glucopyranosyl-(1 --> 2)]- alpha-L-arabinopyranosyl}-16 alpha-hydroxy-13 beta,28-epoxy-oleanan-30-al ( 1) and 3 beta- O-{4- O-[3-hydroxyl-3-methylglutaryl]- beta-D-xylopyranosyl-(1 --> 2)-[ beta-D-glucopyranosyl-(1 --> 6)]- beta-D-glucopyranosyl-(1 --> 4)-[ beta-D-glucopyranosyl-(1 --> 2)]- alpha-L-arabinopyranosyl}-16 alpha-hydroxy-20,30-lactone-olean-12-ene ( 2…
Conformations and coordination schemes of carboxylate and carbamoyl derivatives of the tetraazamacrocycles cyclen and cyclam, and the relation to the…
1998
Abstract This paper discusses and rationalizes the metal coordination pattern of 12- and 14-membered tetraazamacrocyclic carboxylate and carbamoyl ligands based on the cyclen and cyclam framework in light of their acido–basic properties. Structural and protonation data are reviewed in order to illustrate the influence of the free ligand's protonation state and of the pH conditions during the complexation reaction on the final coordination mode of the metallic cations.
Synthesis and characterization of a 1,8-difunctionalized dissymmetrical cyclam copper(II) complex bearing pyridylmethyl and N,N-dimethylcarbamoylmeth…
2001
The new dissymmetrical ligand 1-(N,N-dimethylcarbamoylmethyl)-8-(2-pyridylmethyl)-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane, 5, was synthesized and the physicochemical properties of its copper(II) complex, [CuII(5)](ClO4)2·CH3CN, were determined. UV–Vis, IR, ESR experiments, and X-ray analysis of [CuII(5)](ClO4)2·CH3CN were carried out. The X-ray structure of [CuII(5)](ClO4)2·CH3CN revealed a distorted square pyramid with the four coordinating nitrogen atoms of the macrocycle lying in the basal position. Curiously, the fifth ligand is the N,N-dimethylcarbamoylmethyl group through the oxygen atom and not the pyridylmethyl moiety.
Novel Ni(II) Mixed Ligand Complex Modified Electrode: Catalytic Effect on Anodic Oxidation of Phenol
2004
Cyclic voltammetry, using graphite paste electrode (GPE) and chemically modified GPE with Ni(II) mixed ligand complex (MGPE), is described for sensing and detoxification of phenol. A novel mixed ligand complex of nickel with 1,4,8,11-tetraaza cyclotetradecane (cyclam) and thiocyanate in the molar ratio of 1 : 2 : 5 is synthesized and characterized by spectroscopic and electrochemical studies. The Ni(II)-cyclam-thiocyanate complex behaves as a fast electron-transfer mediator, as nickel ions exist in higher oxidation state of Ni(III) on applying a potential of 1.25 V (vs. Ag/AgCl), which catalyses the oxidation of the target species. The mixed ligand complex, when incorporated in the graphite…
Etude des propriétés de coordination de nouveaux ligands macrocycliques vis-à-vis de cations métalliques en vue de l'utilisation de leurs complexes p…
2011
Noninvasive medical imaging techniques such as single-photon emission computed tomography (SPECT) or positron emission tomography (PET), are valuable tools for the development and validation of new therapeutic molecules. That approach requires the conjugation of a radioactive source emitting either y-rays or positrons with a biological tracer (e.g. DOTATOC). Among the potentially useful radionuclides available, 111In3+ (SPECT), 64Cu2+, and 68Ga3+ (PET) have attracted increasing attention over the last years for medical applications. To minimize the in vivo release of the radioactive cation by transmetalation or transchelation with biological ligands, it is essential to trap selectively the …
A Study Using X-ray Absorption and Emission Spectroscopy of Dioxygen-Binding Xerogels Incorporating Cyclam Units Complexed with Copper Salts.
2005
X-ray absorption spectroscopy was used to elucidate how hybrid xerogels complexed with CuCl2 could reversibly bind molecular dioxygen. Difference EXAFS analyses at the Cu K-edge suggest that dioxygen could bridge two Cu atoms in a μ-η1:η1 peroxo-like conformation with unequal Cu···O distances. Only the short distance (RCu–O1 = 1.86 ± 0.01 A) was unambiguously determined and looks typical of a CuII site. The Cu···Cu internuclear distances would be rather long: RCu–Cu ≈ 4.0 A (3.9 A) for the oxygenated (oxygen-free) xerogels. Cl K-edge EXAFS spectra revealed the pre-existence in the oxygen-free xerogels of CuI sites with short Cl–Cu bonds (2.11 ± 0.03 A). Pentacoordinate CuII sites with a lon…
Fusariose du cyclamen : travaux sur la lutte biologique. Phytoma-La défense des végétaux
2016
SPEIPM; Fusariose du cyclamen : travaux sur la lutte biologique. Phytoma-La défense des végétaux
Diversité génétique au sein de la forme spéciale cyclaminis de Fusarium oxysporum et recherche d’un marqueur spécifique
2014
Le cyclamen est la 3e plante fleurie la plus vendue en France. Une des maladies dommageables de cette culture est la fusariose, causée par Fusarium oxysporum f. sp. cyclaminis (FoCy). Cette forme spéciale, inféodée au cyclamen n’est pas différenciable des autres formes spéciales et souches saprophytes. En se développant dans le xylème, FoCy entraîne la mort de la plante. Quand les symptômes externes apparaissent, la plante est condamnée. La lutte chimique est inefficace, la lutte variétale est inexistante, et les mesures prophylactiques sont difficilement applicables. Pour détecter le pathogène précocement et améliorer la lutte, nous nous sommes intéressés à sa diversité génétique. Pour cel…