Cyclodextrins, the macrocyclic compounds are renowned for their inclusion ability. Several chemical and polymerized derivatives of parent cyclodextrins are synthesized to improve the ...physicochemical/biopharmaceutical properties of drug and inclusion capacity of cyclodextrin. This review article recapitulates the potential aspects of polymerized water-soluble derivative of β-cyclodextrin viz. epichlorohydrin-β-cyclodextrin polymer in different areas of drug delivery. Polymerized cyclodextrin combines the advantage of the properties of polymer (high molecular weight and higher solubility) with the formation of inclusion complex with cyclodextrin. This justifies the superiority of polymerized cyclodextrin over parent cyclodextrin and some other chemically modified and non-polymerized derivatives. The use of polymerized cyclodextrin in various fields like biomedical, pharmaceutical and gene delivery is increasing day-by-day. β-Cyclodextrin-epichlorohydrin polymer is a high molecular weight compound, which acts as an effective drug carrier for enhancing the solubility and oral bioavailability of drugs along with the increase in therapeutic efficiency. The future panorama of polymerized cyclodextrins is quite bright as they can serve as useful multifunctional tools for pharmaceutical scientists to develop and optimize drug delivery through various routes. Also, no information concerning the regulatory status and toxicity of polymerized cyclodextrins is available. So, there is a need to focus on these critical issues for resolving the problems associated with the development and commercialization of drug products.
In this research, an attempt to develop zwitterion composite adsorbent is conducted by modifying chitosan (CHS) with a covalent cross-linker (epichlorohydrin, ECH) and an aluminosilicate mineral ...(zeolite, ZL). The zwitterion composite adsorbent of chitosan-epichlorohydrin/zeolite (CHS-ECH/ZL) is performed multifunctional tasks by removing two structurally different cationic (methylene blue dye, MB), and anionic (reactive red 120 dye, RR120) dyes from aqueous solutions. The surface property, crystallinity, morphology, functionality, and charge of the CHS-ECH/ZL are analyzed using BET, XRD, SEM, FTIR, and pHpzc, analyses, respectively. The influence of pertinent parameters namely CHS-ECH/ZL dosage (0.02–0.5 g), solution pH (4–10), temperature (303−323K), initial dye concentration (30–400 mg/L), and contact time (0–600 min) on the MB and RR120 removal are tested. The research findings revealed that the adsorption isotherm at equilibrium well explained in according to the Freundlich isotherm model, and the recorded adsorption capacities of CHS-ECH/ZL are 156.1 and 284.2 mg/g for MB and RR120 respectively at 30 °C. The mechanism of MB and RR120 adsorption onto the CHS-ECH/ZL indicates various types of interactions namely, electrostatic interaction, hydrogen bonding, and Yoshida H-bonding in addition to n-π interaction. Overall, this research introduces CHS-ECH/ZL composite as an eco-friendly zwitterion adsorbent with good applicability towards the two structurally different cationic and anionic dyes from aqueous environment.
In current research work, chitosan (Chi) was subjected to subsequent physical and chemical modifications by incorporating kaolin clay (KA) into its polymeric structure, and crosslinking process with ...a covalent cross-linker namely epichlorohydrin (ECH) respectively. The final product of crosslinked chitosan-epichlorohydrin/kaolin (Chi-ECH/KA) composite was successfully applied for color removal and chemical oxygen demand (COD) reduction of textile dye namely reactive blue 19 dye (RB19) from aqueous environment. The influence of pertinent parameters, i.e. A: Chi-ECH/KA dose (0.02–0.1 g), B: pH (4–10), and C: time (5–30 min) on the RB19 color removal and COD reduction were statistically optimized by using response surface methodology with Box–Behnken design (RSM-BBD). The experimental data of the adsorption kinetic and the adsorption isotherm demonstrated a better fitness to pseudo-second order model and Langmuir isotherm model respectively. Excellent absorption ability of 560.9 mg/g was recorded for Chi-ECH/KA composite. The calculated thermodynamic functions clarified that the RB19 adsorption process was endothermic and spontaneous in nature. The mechanism of RB19 adsorption onto the Chi-ECH/KA may include electrostatic interactions, hydrogen bonding, Yoshida H-bonding, and n-π interactions. This study introduces Chi-ECH/KA composite as an eco-friendly, potential and multi-function composite bio adsorbent for removal of textile dye and COD reduction from aqueous environment.
•Chitosan-epichlorohydrin/kaolin (Chi-ECH/KA) composite was synthesized.•The Chi-ECH/KA was applied for color removal and COD reduction of reactive blue 19 (RB19) dye.•Box–Behnken design was applied to optimize the adsorption input variables.•The adsorption capacity for RB19 was 560.9 mg/g.•The adsorption isotherm follows Langmuir model.
Protein modifications by crosslinkers have been known to be the most effective way to improve the bonding performance of plant‐based protein adhesives. However, utilizing a huge amount of chemical ...crosslinkers in wood industries rises a concern about product's sustainability and environmental pollution. Therefore, the objective of this study was to improve the water resistance of soy protein (SP) adhesives using renewable bio‐based lignin with minimal use of polyamide‐epichlorohydrin (PAE). The effects of lignin, PAE and combination of lignin‐PAE on SP adhesives were investigated. The results showed that the addition of lignin enhanced the thermal properties of SP adhesives with an increment in the denaturing temperature of 11S protein subunit, whereas PAE elevated the denaturing temperature of 7S protein subunit. Moreover, individual addition of either lignin or PAE increased the elastic modulus and wet adhesion performance of SP adhesives. The same trend was also observed on adhesion performance when both lignin and PAE were used in conjunction. Fourier transform infrared spectroscopy spectra indicated interactions of lignin and PAE to carbonyl, hydroxyl, and amino groups of SP, which lead to a stronger SP network. SP adhesive (10%) modified by a combination of 1% lignin and 1% PAE improved wet adhesion strength by 111% (from 1.8 to 3.8 MPa) with no impact on the spreadability. Further addition of either lignin or PAE did not show a positive effect on the adhesion performance, but rather a decrease in adhesive spreadability due to excessive interactions among SP, lignin, and PAE as well as the interference of the excessive lignin/PAE.
Although water-insoluble cyclodextrin-epichlorohydrin polymers have been known for half a century, these materials are of continued interest to the scientific community, in particular for their ...interesting environmental applications as sorbents in liquid-solid sorption processes. However, in spite of the abundance of literature and conclusive results obtained at the laboratory scale, interpreting the mechanisms of pollutant elimination remains an interesting source of debate and sometimes of contradiction. This review summarizes and discusses the various mechanisms proposed in the literature. A distinction was made in the description of these interactions depending on whether the polymer structures were modified or not.
Sulfone-substituted bicyclo1.1.0butanes and housanes have found widespread application in organic synthesis due to their bench stability and high reactivity in strain-releasing processes in the ...presence of nucleophiles or radical species. Despite their increasing utility, their preparation typically requires multiple steps in low overall yield. In this work, we report an expedient and general one-pot procedure for the synthesis of 1-sulfonylbicyclo1.1.0butanes from readily available methyl sulfones and inexpensive epichlorohydrin via the dialkylmagnesium-mediated formation of 3-sulfonylcyclobutanol intermediates. Furthermore, the process was extended to the formation of 1-sulfonylbicyclo2.1.0pentane (housane) analogues when 4-chloro-1,2-epoxybutane was used as the electrophile instead of epichlorohydrin. Both procedures could be applied on a gram scale with similar efficiency and are shown to be fully stereospecific in the case of housanes when an enantiopure epoxide was employed, leading to a streamlined access to highly valuable optically active strain-release reagents.
A method for immobilization of functional proteins by chemical cross-linking of the protein of interest and uncoated iron oxide nanoparticles in the presence of Epichlorohydrin is described. As a ...result of the cross-linking, the proteins form a matrix in which the particles get entrapped. The optimum concentration of Epichlorohydrin that facilitates immobilization of protein without affecting the functional properties of the protein was determined. This method was used to immobilize several functional proteins and the development and functional activity of Protein A-magnetic nanoparticles (MNPs) is described here in detail. The Protein A-MNPs possess high binding capacity due to the increased surface area of uncoated nanoparticles and robust magnetic separation due to the absence of polymeric coating materials. Protein A-MNPs were successfully used for purification of antibodies and also for immunoprecipitation. We also immobilized enzymes such as horse radish peroxidase and esterase and found that by providing the optimum incubation time, temperature and protein to nanoparticle ratio, we can retain the activity and improve the stability of the enzyme. This study is the first demonstration that Epichlorohydrin can be used to entrap nanoparticles in a cross-linked matrix of protein without impairing the activity of immobilized protein.
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•LTA type membranes were fabricated on capillary and tubular supports.•Fluorescence confocal optical microscopy revealed no defects in the membranes.•Membrane worked well for ...azeotropic H2O/isopropanol/epichlorohydrin mixtures.•Use of capillary supports with thinner wall thickness allowed for a high H2O flux.•Capillary-supported membranes showed marked dehydration even at low H2O contents.
Among the various zeolite membranes, hydrophilic Linde Type A (LTA) zeolite membranes (LTA membranes) are highly desirable for the dehydration of organic solvents. In particular, both high flux and separation factors for H2O can be achieved with such membranes. Therefore, in this study, we fabricated LTA membranes on thin-walled capillary tubes and compared the dehydration performance with those of LTA membranes prepared on conventional tubular supports. We found that neither LTA membrane contained noticeable defects using fluorescence confocal optical microscopy analysis. Accordingly, both membranes effectively dehydrated an azeotropic ternary mixture of H2O/isopropanol (IPA)/epichlorohydrin (ECH), an industrially important mixture. Specifically, the capillary-supported LTA membrane showed better dehydration performance than that on the conventional tubular support, mainly because of the relatively thinner support thickness (ca. 0.35 mm vs. 2 mm of the conventional tubular support). The corresponding H2O flux was ca. 8.02 ± 0.94 kg·m−2·h−1 for the azeotropic ternary mixture (20 wt% H2O/30 wt% IPA/50 wt% ECH) at 70 °C (vs. 4.26 ± 0.39 kg·m−2·h−1 through the LTA membrane on the conventional tube). Further, the H2O/IPA and H2O/ECH separation factors exceeded approximately 10,000. Finally, a comparison with the literature data revealed that the capillary-supported LTA membrane had higher H2O flux and selectivity for H2O/IPA mixtures than other LTA membranes prepared on conventional discs/sheets/tubes.
Oxidative stress is a key mechanism underlying arsenicinduced liver injury, the Kelch-like epichlorohydrin-related protein 1 (Keap1)/nuclear factor E2 related factor 2 (Nrf2) pathway is the main ...regulatory pathway involved in antioxidant protein and phase II detoxification enzyme expression. The aim of the present study was to investigate the role and mechanism of baicalein in the alleviation of arsenic-induced oxidative stress in normal human liver cells.
Normal human liver cells (MIHA cells) were treated with NaAsO
(0, 5, 10, 20 μM) to observe the effect of different doses of NaAsO
on MIHA cells. In addition, the cells were treated with DMSO (0.1%), NaAsO
(20 μM), or a combination of NaAsO
(20 μM) and Baicalein (25, 50 or 100 μM) for 24 h to observe the antagonistic effect of Baicalein on NaAsO
. Cell viability was determined using a Cell Counting Kit- 8 (CCK-8 kit). The intervention doses of baicalein in subsequent experiments were determined to be 25, 50 and 100μM. The intracellular content of reactive oxygen species (ROS) was assessed using a 2',7'-dichlorodihydrofluorescein diacetate (DCFHDA) probe kit. The malonaldehyde (MDA), Cu-Zn superoxide dismutase (Cu-Zn SOD) and glutathione peroxidase (GSH-Px) activities were determined by a test kit. The expression levels of key genes and proteins were determined by real-time fluorescence quantitative polymerase chain reaction (qPCR) and Western blotting.
Baicalein upregulated the protein expression levels of phosphorylated Nrf2 (
-Nrf2) and nuclear Nrf2, inhibited the downregulation of Nrf2 target genes induced by arsenic, and decreased the production of ROS and MDA. These results demonstrate that baicalein promotes Nrf2 nuclear translocation by upregulating p-Nrf2 and inhibiting the downregulation of Nrf2 target genes in arsenic-treated MIHA cells, thereby enhancing the antioxidant capacity of cells and reducing oxidative stress.
Baicalein alleviated arsenic-induced oxidative stress through activation of the Keap1/Nrf2 signalling pathway in normal human liver cells.
This work investigated the redispersion and setting behavior of highly loaded (~ 18 wt.% solids in water) pastes of cellulose nanofibrils (CNFs) with carboxymethyl cellulose (CMC). A single-screw ...extruder was used to continuously process CNF + CMC pastes into cord. The adsorption of CMC onto the CNFs was assessed through zeta potential and titration which revealed a surface charge change of ~ 61% from − 36.8 mV and 0.094 mmol/g COOH for pure CNF to -58.1 mV and 0.166 mmol/g COOH for CNF + CMC with a CMC degree of substitution of 0.9. Dried CNFs with adsorbed CMC was found to be fully redispersible in water and re-extruded back into a cord without any difficulties. On the other hand, chemical treatment with hydrochloric acid, a carbodiimide crosslinker, or two wet strength enhancers (polyamide epichlorohydrin and polyamine epichlorohydrin) completely suppressed the dispersibility previously observed for dried-untreated CNF + CMC. Turbidity was used to quantify the level of redispersion or setting achieved by the untreated and chemically treated CNF + CMC in both water and a strong alkaline solution (0.1 M NaOH). Depending on the chemical treatment used, FTIR analysis revealed the presence of ester, N-acyl urea, and anhydride absorption bands which were attributed to newly formed linkages between CNFs, possibly explaining the suppressed redispersion behavior. Water uptake of the differently treated and dried CNF + CMC materials agreed with both turbidity and FTIR results.
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