Use Of Calixarenes Research Articles

Density Functional Theory Study on the Reactivity and Stability of Calix[n]arene-paba Complexes: Drug Sensor Application

As drug carriers, calixarenes are often investigated and employed in numerous sectors as host molecules. The use of calixarenes in drug delivery systems is a relatively new notion, despite the fact that countless studies have been conducted on calixarenes and their various applications. It is worthwhile to research the computational investigation of the host-guest interaction between calixarenes and para-aminobenzoic acid (PABA) in terms of their binding energy and band gap. The first principles study of PABA sensing by calix [4] arene (C4) and calix [6] arene (C6) based on density functional theory (DFT) was carried out in this study using Quantum ESPRESSO software. By using the computational method, the binding energy, as well as the band gap of C4, C6, PABA, and the novel complexes, C4-PABA, and C6-PABA, were calculated. Different interaction distances were used in the formation of complexes. Our results demonstrate the reduction of the band gap for both complexes. Furthermore, the calculated binding energy shows the promising stability of the complexes. This demonstrates the sensing ability of calixarenes towards PABA and the potential anti-cancer properties of calixarene-PABA in sunscreens.

Advancements in calixarene-protected titanium-oxo clusters: from structural assembly to catalytic functionality.

This review explores calixarenes, a prominent family of third-generation supramolecules celebrated for their distinct hollow, cavity-shaped structures. These macrocycles are intricately assembled by linking multiple phenolic units orthogonally through methylene (-CH2-), sulfur (-S-), or sulfonyl (-SO2-) bridges. This structural framework plays a pivotal role in the intricate assembly of nanoclusters, significantly advancing the field of cluster chemistry. A key focus of current research is the remarkable ability of calixarenes to stabilize titanium-oxo clusters. Our review details the application of calixarenes in constructing titanium-oxo cluster structures, emphasizing how these clusters, when encapsulated within calixarenes, exploit flexible coordination sites for structural modifications and serve as foundational units for more complex assemblies. Additionally, we investigate how these calixarene-stabilized metal-oxo clusters function as versatile scaffolds for catalytically active metal ions, facilitating the creation of bimetallic nanoclusters. These clusters not only exhibit unique structural diversity but also demonstrate exceptional catalytic efficiency. This review aims to inspire ongoing exploration and innovation in the use of calixarenes for the synthesis and application of advanced cluster materials.

Electrochemical Biosensor for Detection of the CYP2C19*2 Allele Based on Exonuclease Ⅲ

Currently, the therapeutic effect of clopidogrel differs considerably among individuals and is thought to be closely related to the genetic polymorphism of CYP2C19. The CYP2C19*2 gene can reduce the antiplatelet aggregation effect of clopidogrel, which increases the risk of major cardiovascular adverse events in patients. In this research, we report a new type of biosensor for the highly sensitive detection of the CYP2C19*2 gene based on exonuclease III assisted electric signal amplification and the use of calixarene to enrich electrical signal substances. Specifically, under the best conditions, the logarithmic concentrations of the analytes have a good linear relationship with the peak current in the range of 0.01 fM to 100 pM and the detection limit is 13.49 aM. The results have also shown that this method has good selectivity, high sensitivity, and stability, etc., and will provide a very promising application for the detection of the CYP2C19*2 gene and other biological molecules by replacing corresponding nucleic acid sequences.

Role of Calixarene in Chemotherapy Delivery Strategies.

Since cancer is a multifactorial disease with a high mortality rate, the study of new therapeutic strategies is one of the main objectives in modern research. Numerous chemotherapeutic agents, although widely used, have the disadvantage of being not very soluble in water or selective towards cancerous cells, with consequent side effects. Therefore, in recent years, a greater interest has emerged in innovative drug delivery systems (DDSs) such as calixarene, a third-generation supramolecular compound. Calixarene and its water-soluble derivatives show good biocompatibility and have low cytotoxicity. Thanks to their chemical–physical characteristics, calixarenes can be easily functionalized, and by itself can encapsulate host molecules forming nanostructures capable of releasing drugs in a controlled way. The encapsulation of anticancer drugs in a calixarene derivate improves their bioavailability and efficacy. Thus, the use of calixarenes as carriers of anticancer drugs could reduce their side effects and increase their affinity towards the target. This review summarizes the numerous research advances regarding the development of calixarene nanoparticles capable of encapsulating various anticancer drugs.

Calixarene-based pure and mixed assemblies for biomedical applications

ABSTRACT The spontaneous preparation of well-defined functional nanoscale systems is very important, since this formulation process requires additional resources, external supply of energy and time. One of the widely used methods of their spontaneous formation is the self-assembling process using of various calixarene building blocks. The relative simplicity of the synthesis of initial calixarene skeleton, the possibility of modifying both of its rims with a wide range of chemical groups, and the presence of a hydrophobic aromatic cavity allow the use of calixarenes to create both individual and mixed aggregates. This article summarises different types of self-assembled calixarene-based amphiphilic aggregates with useful properties. Potential applications of these aggregates in biological nanotechnology are also described.

Use of calixarenes bearing diazonium groups for the development of robust monolayers with unique tailored properties.

Surface modification represents an active field of research that finds applications, amongst others, in the development of medical devices, sensors and biosensors, anti-biofouling materials, self-cleaning surfaces, surfaces with controlled wettability, corrosion resistance, heterogeneous catalysis and microelectronics. For some applications, surface functionalization with a nanometric-size monolayer is desired. In this review, efforts to covalently functionalize a wide array of surfaces with calixarenes bearing diazonium groups are described. More specifically, methodologies to obtain monolayers of calix[4 or 6]arene derivatives on conductive, semi-conductive or insulating surfaces as well as on nanoparticles are presented. The main advantages of this general surface modification strategy (i.e. formation of true monolayers that can be post-functionalized, high robustness and control over the composition of the calixarene-based coating) and its current scope of applications and future challenges are discussed.

Recent applications of chiral calixarenes in asymmetric catalysis.

The use of calixarenes in asymmetric catalysis is receiving increasing attention due to their tunable three-dimensional molecular platforms along with their easy syntheses and versatile modification at the upper and lower rims. This review summarizes the recent progress of synthesis and use of chiral calixarenes in asymmetric syntheses which emerged later than 2010.

Calixarene-based Stationary Phases for Chromatography

Due to their easy functionalization and their unique conformational and recognition properties, calixarenes are attracting molecular platforms for the elaboration of separation systems. Thus, in the last decades, these macrocyclic compounds have been subject to extensive research in analytical chemistry. This review is focused on the use of calixarenes as selectors in the chromatographic separation field. The structures of calixarene derivatives and their applications as stationary phases for gas chromatography as well as high-performance liquid chromatography are described. Keywords: Calixarenes, chromatography, macrocycle, selector, separation mechanism, stationary phase.

Applications of calixarenes in cancer chemotherapy: facts and perspectives.

Research on the therapeutic applications of calixarene derivatives is an emerging area of interest. The anticancer activity of various functionalized calixarenes has been reported by several research groups. Due to their superior geometric shape, calixarenes can accommodate drug molecules by forming inclusion complexes. Controlled release of anticancer drugs by calixarenes might help in targeted chemotherapy. This review summarizes the anticancer potential of the calixarenes and their drug loading properties. The potential use of calixarenes in chemoradiotherapy is also highlighted in brief.

Solvent-free multicomponent synthesis of 2-arylpyridines using p-sulfonic acid calix[6]arene as a reusable catalyst

An efficient methodology for obtaining 2-arylpyrimidines based on the use of p -sulfonic acid calix[6]arene as an organocatalyst is proposed. The methodology involves the formation of 1,2-dihydropyridine intermediates using a variety of aromatic aldehydes with methyl or ethyl acetoacetate and ammonium acetate, which are the same starting materials as in the Hantzsch reaction, under solvent-free reaction conditions, at 25 °C, followed by air oxidation for 12 h. The catalyst efficiency is not compromised after its successive use in reactions. Eleven examples were obtained with very good to excellent yields of 2-arylpyridines (92–62%). This is the first report about the use of calixarenes as catalysts in the multicomponent synthesis of 2-arylpyridines (molecules with potential biological activity).

Purification of flavonoid metal complexes from Alhagi camelorum with calix[4]arene based impregnated resin

The use of calixarenes for the isolation of flavonoids from plant extracts.

DFT/NBO study of Nanotube and Calixarene with anti-cancer drug

AbstractNowadays use of calixarenes and nanotubes are widely spread in the pharmaceutical industry. In this work, interaction of between calix[4]arene and nanotube (6, 6) with Fluorouracil drug are investigated. The DFT calculations have been performed using the Gauss view and Gaussian98 in B3LYP method and 6-31G (d) standard basis set at 298.15K. There are calculated length bond (Å), bond angel (deg), dihedral angel (deg), energy hyperconjucation, and total energy (KJ mol-1), moment dipole (Debye), occupancy between nanotube (6, 6) and calix[4]arene with anticancer drug in B3LYP/6-31G (d) method. These cases and medicines show that complex1 is more stable than complex1. The parameter ofE2, gap energy and∆E°in composite of nanotube- Fluorouracil are higher than calix[4]arene-Fluororacil; therefore, complex1is more stable.

Comparison of drug delivery systems: Nanotube and p- Sulphonatocalix[4]arene, by Density Functional Theory

Nowadays, the use of calixarenes and nanotubes are widely spread in the field of drug delivery. In this work, interaction between p-sulphonatocalix[4]arene and nanotube(6,6)with Fluorouracil drug is investigated. Density function theory (DFT) calculations have been performed using the Gauss view and Gaussian03 by B3LYP (beck three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional) method and 6-31G (d) standard basis set. The length bond (Å), bond angel (degree), dihedral angel (in degree), hyperconjucation energy, and total energy (KJ mol-1), formation energy (KJ mol-1), moment dipole (in Debye) and occupancy of between nanotube (6,6) and p-sulphonatocalix[4]arene with anti-cancer drug are calculated by B3LYP/6-31G (d) method. The results show that composite 2 is more stable than the other composite. The hyperconjucation energy (E 2 ) in the p-sulphonatocalix[4]arene-fluorouracil is higher than that in the other composite. The standard formation energy in the the p-sulphonatocalix[4]arene-fluorouracil is more negative value (lower) to composite 1.

Application of Calixarenes as Macrocyclic Ligands for Uranium(VI): A Review

Calixarenes represent a well‐known family of macrocyclic molecules with broad range of potential applications in chemical, analytical, and engineering materials fields. This paper covers the use of calixarenes as complexing agents for uranium(VI). The high effectiveness of calix[6]arenes in comparison to other calixarenes in uranium(VI) separation process is also presented. Processes such as liquid‐liquid extraction (LLE), liquid membrane (LM) separation, and ion exchange are considered as potential fields for application of calixarenes as useful agents for binding for effective separation from aqueous solutions containing other metal components.

The Use of Calixarenes in Asymmetric Catalysis

The Use of Calixarenes in Asymmetric Catalysis

Calixarenes as New Platforms for Drug Design

Calixarenes, macrocyclic compounds of phenolic units linked by methylene groups at the 2,6-positions, present some of the requirements to serve as platforms for the design and synthesis of biological active compounds. They are also interesting host molecules for chemical biology study purposes. Their basic molecular scaffold has potential ability for molecule recognition; it is promptly synthesized in large amounts, and might be easily modified for maximizing molecular interactions toward relevant guest molecules. Calixarenes present well-defined conformational properties and cavities with molecular dimensions that enable to encapsulate guest drugs. Calixarenes have been shown to have antiviral, antibacterial, antifungal, and anticancer activities (including HIV as target). We provide here an overview of the use of calixarenes either as new chemical entity of distinct biological activities or as host for bioactive guest molecules. The importance of calixarenes for drugs development is discussed. The use of Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) techniques for the study of calixarenes as biological molecule hosts is also described.

Evaluation of the performance of calix[8]arene derivatives as liquid phase extraction material for the removal of azo dyes

This paper presents a study on the removal of azo dyes (Reactive Black 5, Trapaeolin 000, Methyl Orange and Direct Violet 51) with calix[ n]arene derivatives from aqueous solution into the organic phase in order to explore the potential use of calixarenes as low-cost efficient extractants for wastewater dye removal. The carboxylic acid derivative of calix[8]arene shows highest affinity towards the azo dyes. The influence of NaCl (present in the solution) on extraction process was also studied. The extent of the dye removal increased with the addition of NaCl. The proposed extraction mechanism involves several kinds of interactions: electrostatic repulsion between carboxylic acid groups of calix[8]arenes and sulfonate groups of azo dyes, hydrogen bonding and formation of an inclusion complex due to three dimensional cavity type calix[ n]arene molecules through host–guest interactions.

Extraction of strategic materials from the concentrated brine rejected by integrated nuclear desalination systems

Seawater usually contains sixty elements from the Periodic Table. The brine, rejected by a desalination unit, is a concentrate of all compounds contained by seawater. However, some of the elements are very scarce on land and/or are very expensive. There is thus a strong motivation for extracting these materials. Current practice in countries using large-scale desalination is to reject brine back to the sea. Increasing ecological objections are now being voiced since this rejection leads to a degradation of local fauna and flora. Extraction of materials and subsequent brine conditioning for surface storage would therefore be also another advantage for these integrated desalination plants, making them more environmentally friendly. This paper summarizes our preliminary investigations to achieve the above objectives. Elements of interest were first selected on the basis of several economic, physical-chemical and technical criteria. Research was then undertaken to elaborate a common extraction method. After several different solutions, the protocol finally retained comprises a first extraction of Phosphorus through purification by alum. The next step is the recovery of Caesium through an innovative liquid–liquid extraction approach, based on the use of Calixarenes. Indium is then recovered by another liquid–liquid extraction with the help of organic acids. In the final phase germanium and magnesium are extracted. The remaining solution is principally composed of sodium and potassium chlorides, which are separated by hot lixiviation techniques, using the different solubilities of NaCl and KCl. The protocol of extraction thus elaborated would now require exhaustive economic evaluation and experimental verification. These are currently in progress.

Calixarenes as Platforms for the Construction of Multimetallic Complexes

AbstractFor Abstract see ChemInform Abstract in Full Text.

Biopharmaceutical applications of calixarenes

During the last 15 years, water soluble calixarenes and especially para-sulphonato-calix[n]arene and amphiphilic calixarenes have been the subject of growing interest in the biological domain. This article provides an overview of the studies, by our group and other research groups, that led to the elucidation of biological and biopharmaceutical activity of these calixarenes. The different studies concerning the specific interac- tions of calixarenes with molecules such as organic and inorganic ions, peptides, polar or neutral organic molecules and biomolecules including proteins and lipids are discussed. The interactions have been studied in solution and in the solid and gaseous using a wide range of methods such as NMR spectroscopy, RP-HPLC, micro-calorimetry, X-ray crystallography, atomic force microscopy, Langmuir balance, etc. Increasingly detailed knowledge is being obtained on the mechanism of the interactions of the calixarenes with biomolecules. At this time, the calixarenes have demonstrated neither toxicity or immune responses, further increasing their interest in the field of biopharmaceutical applications. Undoubtedly, the use of calixarenes as biopharmaceutical molecules will show a large increase in the future.