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81.
Najah Cheriaa Rym Abidi Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(3-4):223-229
The synthesis of a new di-imidazolyl-di-methoxy acetamido p-tert-butylcalix[4]arene 4 is reported. 4 has been prepared by reacting the corresponding di-methyl ester di-methoxy derivative with histamine in 1:1 mixture of methanol: toluene. The binding properties of 4 towards alkali, alkaline earth, transition (Zn2+, Co2+) and heavy (Pb2+, Cd2+) metals have been investigated along with the complexes stoichiometries. The 1H-NMR spectra of complexes show the location of cations in receptor 4. Partial cone conformation is observed only with strontium and calcium whereas the cone conformation is detected with most of the cations. Comparison of the complexation results with those obtained for di-imidazolyl acetamido p-tert-butylcalix[4]arene 3 missing the methyl groups is also reported. 相似文献
82.
Amel Ben Othman Young Hoon Lee Keisuke Ohto Rym Abidi Yang Kim Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(1-2):187-191
Hyperbranched molecules, 4–8, based on calixarenes attached to newly synthesised cores 2 and 3 have been prepared. Preliminary complexation studies of the complexation of Zn(Pic)2 by 8 showed that the ligand prefers to bind the picrate anions. 相似文献
83.
New acylhydrazone derivatives 1–6 have been synthesized by condensation of tert‐butylphenoxyhydrazide and cinnamaldehyde A or β‐chloro‐α,β‐unsaturated aldehydes B–F . They were characterized by IR, (1H, 13C, 19F) nuclear magnetic resonance (NMR), and high‐resolution mass spectroscopy. The NMR data show the existence of the cis/trans‐amide conformers due to N–C(O) bond rotation in addition to the E/Z isomers around the C=C bond of some of the starting aldehydes. The solvent polarity effects on the ratios of the cis/trans‐amide rotamers have also been investigated. Importantly, rotational barriers around the N–C(O) bond for all compounds 1–6 (62.9–68.8 kJ mol–1) were calculated using the coalescence‐temperature method according to the Eyring equation. The results are discussed and compared with those previously reported for related acylhydrazones of aryl adehydes and acetone. 相似文献
84.
L. Baklouti R. Abidi P. Thuery M. Nierlich Z. Asfari J. Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(4):323-325
The direct preparation of the sodium complex of 5,11,17,23-tetra(tert-butyl)-25,27-di(ethoxymethoxy)-26,28-(diethylacetamido) calix[4]arene 1.NaI is reported. The crystal structure of 1.NaI shows the calix unit to be in a cone conformation with the sodium located in the cavity delineated by the oxygen atoms. 相似文献
85.
Dr. Iwona Nierengarten Dr. Sebastiano Guerra Dr. Haifa Ben Aziza Dr. Michel Holler Prof. Rym Abidi Prof. Joaquín Barberá Prof. Robert Deschenaux Dr. Jean‐François Nierengarten 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(18):6185-6189
New liquid‐crystalline pillar[5]arene derivatives have been prepared by grafting first‐generation Percec‐type poly(benzylether) dendrons onto the macrocyclic scaffold. The molecules adopt a disc‐shaped structure perfectly suited for self‐organization into a columnar liquid‐crystalline phase. In this way, the pillar[5]arene cores are piled up, thus forming a nanotubular wire encased within a shell of peripheral dendrons. The capability of pillar[5]arenes to form inclusion complexes has been also exploited. Specifically, detailed binding studies have been carried out in solution with 1,6‐dicyanohexane as the guest. Inclusion complexes have also been prepared in the solid state. Supramolecular organization into the Colh mesophase has been deduced from X‐ray diffraction data and found to be similar to that observed within the crystal lattice of a model inclusion complex prepared from 1,4‐dimethoxypillar[5]arene and 1,6‐dicyanohexane. 相似文献
86.
Abidi Awatef Manaa Nessrin Mohamed Degani Estellé Patrice Borjini Mohammed Naceur 《Journal of Thermal Analysis and Calorimetry》2022,147(22):12391-12408
Journal of Thermal Analysis and Calorimetry - A parametric numerical investigation has been performed of three-dimensional combined thermal–solutal capillary and buoyancy convection... 相似文献
87.
Sanjit Acharya Noureddine Abidi Rajeev Rajbhandari Frank Meulewaeter 《Cellulose (London, England)》2014,21(6):4693-4706
Cotton fabric is usually dyed with reactive dyes. During the dyeing process, a large amount of salt is required to achieve higher exhaustion of the dye from the dyebath onto the fiber. Dyeing of cotton with reactive dyes has a substantial environmental impact due to the discharge of a large volume of highly colored and saline effluents. Chemical cationization allows cotton fibers to be dyed without salt by chemically modifying cellulosic macromolecules to introduce positively charged sites. In this study, cotton fabric was cationized using (3-chloro-2-hydroxylpropyl) trimethyl-ammonium chloride (CHPTAC). Dye uptake was assessed using two reactive dyes, CI Reactive Blue 235 and CI Reactive Blue 19. Dye exhaustion kinetics were determined using a Datacolor-HueMetrix Monitor system. Analysis of variance demonstrated significant effects of CHPTAC concentration and exhaustion time on the percent exhaustion. Color strength at the end of the dyeing cycle was significantly higher for cationized fabrics compared to the control fabric. This work shows that treatment of cotton with CHPTAC enhanced dye uptake properties due to the introduction of cationic sites and resulted in superior dyeing without the addition of salt. 相似文献
88.
Ferid Abidi Neyssene Aissaoui Jean-Marc Chobert Thomas Haertlé Mohamed Nejib Marzouki 《Applied biochemistry and biotechnology》2014,174(1):186-205
In the present study, purification and properties of an extracellular neutral serine protease from the fungus Penicillium italicum and its potential application as an antioxidant peptides producer are reported. The protease was purified to homogeneity using ammonium sulfate precipitation, Sephacryl S-200 gel filtration, diethylaminoethanol (DEAE)-Sepharose ion exchange chromatography, and TSK-HPLC gel filtration with a 10.2-fold increase in specific activity and 25.8 % recovery. The purified enzyme appeared as single protein band with a molecular mass of 24 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for the proteolytic activity were pH 7.0 and 50 °C, respectively. The enzyme was stable in the pH range of 6.0–9.0. The protease was activated by divalent cations such as Ca2+ and Mg2+. Complete inhibition of the purified enzyme by phenylmethylsulfonyl fluoride confirmed that the protease was of serine-type. The purified enzyme revealed high stability and relatively broad specificity. Scorpaena notata muscle protein hydrolysates prepared using purified serine protease (protease from P. italicum (Prot-Pen)) showed good in vitro antioxidative activities. The antioxidant activities of Scorpaena muscle protein hydrolyzed by Prot-Pen (SMPH-PP) were evaluated using various antioxidant assays: 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, ferrous chelating activity, and DNA nicking assay. SMPH-PP showed varying degrees of antioxidant activity and almost the same strongest protection against hydroxyl radical induced DNA breakage. 相似文献
89.
A Metal‐Free Synthesis of 2‐Alkyl(or Aryl) Thiomethyl‐2‐cyclohexenones from Cyclic Morita–Baylis–Hillman Bromides
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Under mild conditions, an efficient and rapid S‐allylation of thiols with cyclic Morita–Baylis–Hillman (MBH) bromides without the need of a transition‐metal catalyst or an expensive additive is described herein. Treatment of the MBH bromides with various thiols or ethane‐1,2‐dithiol in the presence of Et3N regioselectively affords the corresponding 2‐alkyl(or aryl) thiomethyl‐2‐cyclohexenones or the perhydro benzo[1,4]dithiepinone, respectively, in moderate to good yields (40 – 73%). The reaction is rapid and carried out in THF at room temperature. 相似文献
90.
Changshun Ruan Yongjun Zhu Xin Zhou Noureddine Abidi Yang Hu Jeffrey M. Catchmark 《Cellulose (London, England)》2016,23(6):3417-3427
Bacterial cellulose (BC) is a promising biomaterial as well as a model system useful for investigating cellulose biosynthesis. BC produced under static cultivation condition is a hydrous pellicle consisting of an interconnected network of fibrils assembled in numerous dense layers. The mechanisms responsible for this layered BC assembly remain unknown. This study used calcofluor as a fluorescent marker to examine BC layer formation at the air/liquid interface. Layers are found to move downward into the media after formation while new layers continue to form at the air/liquid interface. Calcoflour is also known to reduce the crystallinity of cellulose, changing the mechanical properties of the formed BC microfibrils. Consecutive addition and accumulation of calcofluor in the culture medium is found to disrupt the layered assembly of BC. BC crystalllinity decreased by 22 % in the presence of 12 % calcofluor (v/v) in the medium as compared to BC produced without calcofluor. This result suggests that cellulose crystallinity and the mechanical properties which crystallinity provides to cellulose are major factors influencing the layered BC structure formed during biosynthesis. 相似文献