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31.
Puglisi A Spencer J Oliveri V Vecchio G Kong X Clarke J Milton J 《Dalton transactions (Cambridge, England : 2003)》2012,41(10):2877-2883
3-Hydroxy-1,2-dimethylpyridin-4(1H)-one (deferiprone) is a successful iron chelator, which has been widely investigated for its activity in mitigating iron overload and in protecting against oxidative stress due to Reactive Oxygen Species (ROS). Herein, we present the synthesis, characterisation, physicochemical properties and antioxidant activity of two novel bioconjugates of β-cyclodextrin bearing the deferiprone moiety either on the upper rim (1) or on the lower rim (2) of the cyclodextrin and their iron(III) complexes. Protonation and iron stability constants were measured by spectrophotometric titration for the two systems and antioxidant activity studied for both the ligands and the iron(III) complexes. 相似文献
32.
Lo Nigro R Malandrino G Toro RG Losurdo M Bruno G Fragalà IL 《Journal of the American Chemical Society》2005,127(40):13772-13773
CaCu3Ti4O12 (CCTO) thin films were successfully grown on LaAlO3(100) and Pt/TiO2/SiO2/Si(100) substrates by a novel MOCVD approach. Epitaxial CCTO(001) thin films have been obtained on LaAlO3(100) substrates, while polycrystalline CCTO films have been grown on Pt/TiO2/SiO2/Si(100) substrates. Surface morphology and grain size of the different nanostructured deposited films were examined by AFM, and spectroscopic ellipsometry has been used to investigate the electronic part of the dielectric constant (epsilon2). Looking at the epsilon2 curves, it can be seen that by increasing the film structural order, a greater dielectric response has been obtained. The measured dielectric properties accounted for the ratio between grain volumes and grain boundary areas, which is very different in the different structured films. 相似文献
33.
Carlo Costa Antonella Bertazzo Graziella Allegri Ornella Curcuruto Pietro Traldi 《Journal of heterocyclic chemistry》1992,29(6):1641-1647
The extraction and the isolation of some alkaloids from the roots of an African plant (Securidaca Longipedunculata Fres) are reported. The structural characterization was performed by mass spectrometry. Alternative ionization methods (FAB and EI), collisionally-induced decomposition experiments and accurate mass measurements revealed the presence of elymoclavine and dehydroelymoclavine and the presence of a new ergoline alkaloid. 相似文献
34.
Dr. Denise Lovison Dr. Dario Alessi Dr. Lorenzo Allegri Dr. Federica Baldan Dr. Maurizio Ballico Prof. Giuseppe Damante Dr. Marilisa Galasso Prof. Daniele Guardavaccaro Dr. Silvia Ruggieri Prof. Andrea Melchior Dr. Daniele Veclani Dr. Chiara Nardon Prof. Walter Baratta 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(33):e202200200
The chiral cationic complex [Ru(η1-OAc)(CO)((R,R)-Skewphos)(phen)]OAc ( 2 R ), isolated from reaction of [Ru(η1-OAc)(η2-OAc)(R,R)-Skewphos)(CO)] ( 1 R ) with phen, reacts with NaOPiv and KSAc affording [RuX(CO)((R,R)-Skewphos)(phen)]Y (X=Y=OPiv 3 R ; X=SAc, Y=OAc 4 R ). The corresponding enantiomers 2 S - 4 S have been obtained from 1 S containing (S,S)-Skewphos. Reaction of 2 R and 2 S with (S)-cysteine and NaPF6 at pH=9 gives the diastereoisomers [Ru((S)-Cys)(CO)(PP)(phen)]PF6 (PP=(R,R)-Skewphos 2 R -Cys; (S,S)-Skewphos 2 S -Cys). The DFT energetic profile for 2 R with (S)-cysteine in H2O indicates that aquo and hydroxo species are involved in formation of 2 R -Cys. The stability of the ruthenium complexes in 0.9 % w/v NaCl solution, PBS and complete DMEM medium, as well as their n-octanol/water partition coefficient (logP), have been evaluated. The chiral complexes show high cytotoxic activity against SW1736, 8505 C, HCT-116 and A549 cell lines with EC50 values of 2.8–0.04 μM. The (R,R)-Skewphos derivatives show higher cytotoxicity compared to their enantiomers, 4 R (EC50=0.04 μM) being 14 times more cytotoxic than 4 S against the anaplastic thyroid cancer 8505 C cell line. 相似文献
35.
A new ligand, N,N,N′,N′-tetramethylethylenediamine, has been used to grow ZnO nanorods on silicon substrates via a two steps approach. A preliminary seeding on silicon substrates has been combined with chemical bath deposition using a Zinc acetate–N,N,N′,N′-tetramethylethylenediamine aqueous solution. The used diamino ligand has been selected as Zn2+ complexing agent and the related hydrolysis generates the reacting ions (Zn2+ and OH−) responsible for the ZnO growth. The seed layer has been annealed at low temperature (<200 °C) and the ZnO nanorods have been grown on this ZnO amorphous layer. There is experimental evidence that the ligand concentration (ranging from 5 to 50 mM) strongly affects the alignment of ZnO nanorods on the substrate, their lateral dimension and the related surface density. Length and diameter of ZnO nanorods increase upon increasing the ligand concentration, while the nanorod density decreases. Even more important, it has been demonstrated, as proof of concept, that chemical bath deposition can be usefully combined with colloidal lithography for selective ZnO nanorod deposition. Thus, by patterning the ZnO seeded substrate with polystyrene microsphere colloidal lithography, regular Si hole arrays, spatially defined by hexagonal ZnO nanorods, have been successfully obtained. 相似文献
36.
Filippi A Fraschetti C Renzi G Roselli G Speranza M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(30):7913-7919
The mechanism and stereochemistry of the intracomplex solvolysis of proton-bound complexes [Y...H...M]+ between M = CH3 (18)OH and Y = 1-arylethanol [(S)-1-(para-tolyl)ethanol (1S), (S)-1-(para-chlorophenyl)ethanol (2S), (S)-1-(meta-alpha,alpha,alpha-trifluoromethylphenyl)ethanol (3S), (S)-1-(para-alpha,alpha,alpha-trifluoromethylphenyl)ethanol (4S), (R)-1-(pentafluorophenyl)ethanol (5R), (R)-alpha-(trifluoromethyl)benzyl alcohol (6R), and (R)-1-phenylethanol (7R)] have been investigated in the gas phase (CH3F; 720 Torr) in the 25-140 degrees C temperature range. Gas-phase solvolysis of [Y...H...M]+ (Y=2S, 3S, 4S, and 7R) leads to extensive racemization above a characteristic temperature t(#) (e.g. at t(#)>60 degrees C for 7R), whereas below that temperature the reaction displays a preferential retention of configuration. Predominant retention of configuration is instead observed in the intracomplex solvolysis of [Y...H...M]+ (Y=1S, 4S, 5R, and 6R) with the temperature range investigated (25 相似文献
37.
Surface plasmon resonance imaging is used to demonstrate the recognition by the Ricinus communis agglutinin of a new SOD mimic, a bioconjugate of the manganese(II) complex of 1,4,7,10,13-pentaazacyclopentadecane with galactose. 相似文献
38.
A study was undertaken to evaluate whether the fairy shrimpChirocephalus diaphanus(Crustacea: Anostraca) could be considered as a species capable of biomonitoring environmental contamination by accumulating trace elements. This preliminary investigation aimed at assessing the levels of As, Cd, Cu, Hg, Pb, Se, and Zn in natural waters as well as in adults and cysts of fairy shrimps sampled from five different sites in central Italy. Trace elements were determined by inductively coupled plasma (ICP)-based spectrometry. In particular, ICP–mass spectrometry (ICP-MS) was resorted to in most cases due to its high detection power. Pretreatment of samples (adults and cysts) consisted basically in the HNO3-assisted microwave digestion of the material. The highest levels of trace elements were found in the anostracan cysts, with concentration ranges (μg/g) of 0.464–3.11 for As, up to 0.820 for Cd, 2.62–13.0 for Cu, 0.011–0.213 for Hg, 0.966–8.46 for Pb, 0.295–2.45 for Se, and 16.4–50.4 for Zn. On the other hand, the lowest concentrations were found in natural waters, with values close to the ICP-MS detection power for some elements. These data are probative of a bioconcentration process, the extent of which is proportional to the environmental level of each element. This may turn out to be useful in planning biological monitoring and assessing ecotoxicological consequences which might ensue from the diffusion of the exploitation of such organisms in aquaculture. 相似文献
39.
Glaucia R. Martinez Flávia Garcia Jean Cadet Graziella E. Ronsein Marisa H.G. Medeiros 《Tetrahedron》2006,62(46):10762-10770
We report herein the synthesis of a new hydrophilic and non-ionic anthracene derivative, the N,N′-di-(2,3-dihydroxypropyl)-9,10-anthracenedipropanamide. The evaluation of this compound as chemical trap of singlet molecular oxygen by using labeling experiments and HPLC-MS analysis showed that it could be efficiently used in biological investigations. 相似文献
40.
Ab initio SCF-MO-LCAO calculations have been performed with a 7s3p/3s GTO basis set for the CH3O--lactam + OH– reaction which is related to the mode of action of -lactam antibiotics. The comparison of the present results with the previous ones for -lactam + OH– and 3-cephem + OH– shows that the CH3O substitution has a negligible effect on the amidic bond breaking of -lactam, so that this group probably influences other steps of the antibiotic reactivity of cephaloporins. 相似文献