Novel Amphiphilic Star-Shaped Poly(2-Oxazoline)s with Calix[4]Arene Branching Center

Novel amphiphlic four-arm star-shaped poly (2-alkyl-2-oxazoline) s with calix [4] arene core were synthesized using the “grafting from” approach. The chlorosulfonated calix [4] arene derivative was synthesized and successfully applied as a multifunctional initiator for the cationic ring-opening polymerization of 2-alkyl-2-oxazolines. Obtained star-shaped poly (2-alkyl-2-oxazoline) s were characterized by means of NMR, UV-Vis spectroscopy and gel-permeation chromatography. It was shown that star-shaped poly (2-isopropyl-2-oxazoline) perform thermosensitivity in aqueous solutions.

Application of Silica Supported Calix[4]arene Derivative as Anti-reversion Agent in Tire Tread Formulation

In this research the influence of the silica supported calix[4]arene derivative (SS-Calix) on the reversion resistance, mechanical properties and thermal behavior of NR/BR tire tread formulation was investigated by the oscillating disc rheometer, FTIR, TGA and tensile testing. The results revealed that the reversion behavior of NR/BR vulcanizate is affected by SS-Calix. The data obtained from curing characteristics and thermal stability of test pieces indicate that, SS-Calix acts as an anti-reversion for rubbery materials that are exposed to thermal shock in the early stages of temperature rise. It’s predicted that these results are due to the interaction between the OH groups present in the SS-Calix surface and the carbon of the polymer chains. The broad peak observed in the IR spectrum around 1824 cm−1 which is referred to C=O bond, confirms this prediction. In addition, the presence of SS-Calix in compound causes to increase modulus and hardness but reduce elongation and resilience.

Polymerization of a biscalix[5]arene derivative

A calix[5]arene appended monomer molecule was subjected to polymerization reaction to yield corresponding methacrylate polymers. The calix[5]arene appended polymers showed excellent encapsulation capability for fullerene molecules.

Nucleophile-Induced Transformation of Phenoxathiin-Based Thiacalixarenes

Oxidized phenoxathiin-based macrocycle, an easily accessible thiacalix[4]arene derivative, consists of a unique set of structural elements representing a key prerequisite for the unexpected reactivity described in this paper. As proposed,...

Improvement of the Anticancer Activity of Chlorambucil and Ibuprofen via Calix[4]arene Conjugates

Background: One of the possible ways of improving the activity and selectivity profile of anticancer agents is to design drug carrier systems employing nanomolecules. Calix[4]arene derivatives and chlorambucil and ibuprofen are important compounds that exhibit interesting anticancer properties. Objective: The objective of this article is the synthesis of new calix[4]arene-derivative conjugates of chlorambucil or ibuprofen with potential anticancer activity. Methods: Cytotoxicity assays were determined using the protein-binding dye sulforhodamine B (SRB) in microculture to measure cell growth as described [19, 20]. Conjugates of chlorambucil and resorcinarene-dendrimers were prepared in 2% DMSO and added into the culture medium immediately before use. Control cells were treated with 2% DMSO. Results: Thus, calix[4]arene-derivative conjugates of chlorambucil or ibuprofen showed good stability of the chemical link between drug and spacer. Evaluation of the cytotoxicity of the calix[4]arene chlorambucil or ibuprofen conjugates employing a sulforhodamine B (SRB) assay in K-562 (human chronic myelogenous leukemia cells) and U-251 (human glioblastoma cells) demonstrated that the conjugate was more potent as an antiproliferative agent than free chlorambucil and ibuprofen. The conjugates did not show any activity against the COS-7 African green monkey kidney fibroblast cell line. Conclusion: In the paper, we report the synthesis and spectroscopic analyses of new calix[4]arene derivative conjugates of chlorambucil or ibuprofen. Cytotoxicity assays revealed that at 10 μM, the conjugates were very active against K-562 (human chronic myelogenous leukemia cells) and U- 251 (human glioblastoma cells) cancer cells' proliferation. In order to explain the molecular mechanisms involved in the anticancer activity of calix[4]arene chlorambucil or ibuprofen conjugates, our research will be continued.

Synthesis and Characterization of New Heterocyclic Compounds from Calix [4] arene Derivative

In this work, a new heterocyclic compounds derived from Calix[4]arene Derivative had been synthesized. The characterization of the produced compounds was performed using melting point, FT-IR spectroscopy and some of them with 1H-NMR spectroscopy. The spectral data confirm the formation of these compounds. This research includes the following two parts:- Part 1: Synthesis of Calix[4]arane Derivative from reaction Calix[4]arane with 4- Aminobutyric acid to produce ester compound this part4-Aminobutyric acid reaction with freshly distilled thinly chloride , the produce final was purified via distillation below pressure reduced. The product was purified by repeated recrystallization. In this step Converted the substituted carboxylic acid to substituted acid chloride included to obtained good leaving group the compound product containing primary amine and the reaction of Calix[4]arane Derivative with compounds containing carbonyl group(aldehyde or ketone) the carbonyl group of aldehyde or ketone react with primary amine to produce imine compounds(Schiff bases. Part 2: Reaction of produced Schiff base compounds with mercaptoacetic acid (thioglycolic acid) or maleic anhydride to synthesized new heterocyclic compounds Compounds with heterogeneous ring are characterized by having many biological activitiesWhich attracts the attention of researchers, and accordingly various derivatives containing sulfur or oxygen were prepared for heterocyclic compounds, these prepared compounds can have inhibitory activity for some bacteria, fungi, and viruses.