Search results for "macrocyclic compound"

Polyfunctional recognition of pyridinedicarboxylate anions with macrocyclic polyamine receptors containing heteroaromatic groups.

2008

The interaction of the biologically relevant anions deriving from the six pyridinedicarboxylic acids (H2PDC) with two macrocyclic receptors containing a pentamine chain and a bipyridine (1) or a phenanthroline (2) moiety, as well as with the aliphatic analogue [21]aneN7 (3), was studied by means of spectroscopic methods (UV-vis, NMR) and potentiometric titrations affording the stability constants of the adducts formed. All three receptors form stable complexes with the substrates thanks to the formation of several salt bridges and hydrogen bond contacts, as observed in the crystal structure of the H8[3(2,6-PDC)4] x H2O x 0.5 EtOH solid compound. Additional pi-stacking interactions between t…

Electrochemistry of copper complexes with macrocyclic polyamines containing pyrazole units.

2006

The voltammetric behaviour of bi- and mono-nuclear complexes formed in solution by Cu(2+) with three polyazacyclophanes containing pyrazole units in aqueous solution is described. Cyclic and square wave voltammetric responses at glassy carbon electrodes indicate that the reduction of copper-macrocycle complexes in solution takes place in two successive one-electron per Cu transfer processes coupled with preorganization and protonation reactions that mimic the behaviour of superoxide dismutase. The electrochemistry of ternary Cu(2+)-receptor-dopamine complexes exhibits significant differences with respect to the protection of the neurotransmitter from post-electron transfer cyclization react…

A Ferromagnetic [Cu3(OH)2]4+Cluster Formed inside a Tritopic Nonaazapyridinophane: Crystal Structure and Solution Studies

2009

Manganese(II) complexes of scorpiand-like azamacrocycles as MnSOD mimics.

2011

Mn(II) complexes of scorpiand-type azamacrocycles constituted by a tretrazapyridinophane core appended with an ethylamino tail including 2- or 4-quinoline functionalities show very appealing in vitro SOD activity. The observed behaviour is related to structural and electrochemical parameters.

One-Pot Synthesis and AFM Imaging of a Triangular Aramide Macrocycle

2014

Macrocyclizations in exceptionally good yields were observed during the self-condensation of N-benzylated phenyl p-aminobenzoates in the presence of LiHMDS to yield three-membered cyclic aramides that adopt a triangular shape. An ortho-alkyloxy side chain on the N-benzyl protecting group is necessary for the macrocyclization to occur. Linear polymers are formed exclusively in the absence of this Li-chelating group. A model that explains the lack of formation of other cyclic congeners and the demand for an N-(o-alkoxybenzyl) protecting group is providedon the basis of DFT calculations.High-resolution AFM imaging of the prepared molecular triangles on a calcite(10.4) surface shows individual …

Cation binding resorcinarene bis-crowns: the effect of lower rim alkyl chain length on crystal packing and solid lipid nanoparticles

2012

A group of seven resorcinarene bis-crown ethers (CNBC5) with two polyether bridges at the upper rim and either propyl, butyl, pentyl, heptyl, nonyl, decyl or undecyl groups at the lower rim were synthesized and their binding properties with Cs+ were investigated by NMR titration. The bis-crowns form 1:2 complexes with Cs+ with binding constants of logK 4–5. Crystal structures of bis-crowns and their Cs+ and K+ complexes were studied and different packing motifs were found depending on the alkyl chain length. Short ethyl, propyl and butyl alkyl chains gave a layer or pillar packing where the polar and non-polar regions cannot be distinguished, whereas longer pentyl and decyl chains formed bi…

Scorpiand-like azamacrocycles prevent the chronic establishment of Trypanosoma cruzi in a murine model.

2013

Chagas disease is today one of the most important neglected diseases for its upcoming expansion to non-endemic areas and has become a threat to blood recipients in many countries. In this study, the trypanocidal activity of ten derivatives of a family of aza-scorpiand like macrocycles is evaluated against Trypanosoma cruzi in vitro and in vivo murine model in which the acute and chronic phases of Chagas disease were analyzed. The compounds 4, 3 and 1 were found to be more active against the parasite and less toxic against Vero cells than the reference drug benznidazole, 4 being the most active compound, particularly in the chronic phase. While all these compounds showed a remarkable degree …

The fungal lactone oxacyclododecindione is a potential new therapeutic substance in the treatment of lupus-associated kidney disease.

2013

Recently oxacyclododecindione (Oxa), a macrocyclic lactone isolated from the imperfect fungus Exserohilum rostratum, has been described as a potent transcription inhibitor of inducible proinflammatory and profibrotic genes in cell culture models. As kidney disease in systemic lupus erythematosus is characterized by aberrant expression of inflammatory mediators and infiltration of immune cells, we investigated the effect of Oxa in MRL-Fas(lpr) mice, a model of systemic lupus erythematosus. These mice develop a spontaneous T-cell and macrophage-dependent autoimmune disease including severe glomerulonephritis that shares features with human lupus. Comparable to the results of in vitro models, …

Ombitasvir, paritaprevir, and ritonavir, with or without dasabuvir, plus ribavirin for patients with hepatitis C virus genotype 1 or 4 infection with…

2017

Summary Background We ran a compassionate use nationwide programme (ABACUS) to provide access to ombitasvir, paritaprevir, and ritonavir, with dasabuvir, plus ribavirin for hepatitis C virus (HCV) genotype 1 infection and ombitasvir, paritaprevir, and ritonavir, plus ribavirin for HCV genotype 4 infection in patients with cirrhosis at high risk of decompensation while approval of these regimens was pending in Italy. Methods In this prospective observational study, we collected data from a compassionate use nationwide programme from March 17, 2014, to May 28, 2015. Patients with HCV genotype 1 infection and cirrhosis at high risk of decompensation were given coformulated ombitasvir (25 mg), …

Safety and efficacy of ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in patients over 65 years with HCV genotype 1 cirrhosis

2018

Purpose: To analyse safety and efficacy of treatment based on ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in the sub-group of GT1 patients older than 65 years. Methods: We collected data extracted from the ABACUS compassionate-use nationwide Italian programme, in patients with cirrhosis due to hepatitis C virus (HCV) Genotype-1 (GT1) or 4 and at high risk of decompensation. GT1-HCV-infected patients received once-daily ombitasvir/paritaprevir, with the pharmacokinetic enhancer ritonavir (25/150/100 mg) and twice-daily dasabuvir (250 mg) plus Ribavirin (RBV) (OBV/PTV/r + DSV + RBV) for 12 (GT1b) or 24 (GT1a) weeks. Endpoints were to evaluate safety and efficacy, the latter def…