Design and Synthesis of Thiourea-Conjugating Organic Arsenic D-Glucose with Anticancer Activities.

Organic arsenic compounds such as p-aminophenylarsine oxide (p-APAO) are easier for structural optimization to improve drug-like properties such as pharmacokinetic properties, therapeutic efficacy, and target selectivity. In order to strengthen the selectivity of 4-(1,3,2-dithiarsinan-2-yl) aniline 7 to tumor cell, a thiourea moiety was used to strengthen the anticancer activity. To avoid forming a mixture of α/ß anomers, the strategy of 2-acetyl's neighboring group participation was used to lock the configuration of 2,3,4,6-tetra-O-acetyl-ß-d-glucopyranosyl isothiocyanate from 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide. 1-(4-(1,3,2-dithiarsinan-2-yl) aniline)-2-N-(2,3,4,6-tetra-O-acetyl-ß-d-glucopyranos-1-yl)-thiourea 2 can increase the selectivity of human colon cancer cells HCT-116 (0.82 ± 0.06 µM vs. 1.82 ± 0.07 µM) to human embryonic kidney 293T cells (1.38 ± 0.01 µM vs. 1.22 ± 0.06 µM) from 0.67 to 1.68, suggesting a feasible approach to improve the therapeutic index of arsenic-containing compounds as chemotherapeutic agents.

Starch of oat derived nanostructured Fe/Mn bimetallic carbon materials for sulfamethoxazole degradation via peroxymonosulfate activation.

Fe/Mn bimetallic carbon materials were synthesized by combining oat and urea, followed by and carbonization processes, the activity and mechanism of the obtained materials in activating peroxymonosulfate (PMS) for sulfamethoxazole (SMX) degradation were determined. Data suggested that the obtained material (CN@FeMn-10-800) showed the optimal performance for SMX degradation under the1:8:0.05:0.05 mass ratios of oat/urea/Fe/Mn. Around 91.2 % SMX (10 mg L-1) was removed under the conditions of 0.15 g L-1 CN@FeMn-10-800 and 0.20 g L-1 PMS. The CN@FeMn-10-800 showed great adaptability under different conditions, satisfactory activation repeatability and versatility. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that core-shell structure with rich porous of CN@FeMn-10-800 was achieved. Quenching test and electron paramagnetic resonance (EPR) indicated that surface bound oxygen and singlet oxygen (1O2) were the dominate reactive groups in this system. X-ray photoelectron spectroscopy (XPS) suggested that graphite N, Fe0, Fe3C and Mn(II) were the dominant active sites. Through the work, a simple strategy could be found to make high-value use of biomass and use it to effectively purified wastewater.

Nitrogen doped magnetic porous carbon derived from starch of oatmeal for efficient activation peroxymonosulfate to degradation sulfadiazine.

Nitrogen doped magnetic porous carbon catalyst based on starch of oatmeal was obtained by mixing and pyrolysis process, and its catalytic activity of peroxymonosulfate activation for sulfadiazine degradation was evaluated. When ratio of oatmeal/urea/iron was 1: 2: 0.1, CN@Fe-10 had the best catalytic activity to degrade sulfadiazine. Around 97.8 % removal of 20 mg L-1 sulfadiazine was achieved under incorporating of 0.05 g L-1 catalyst and 0.20 g L-1 peroxymonosulfate. Good adaptability, stability and universality of CN@Fe-10 were verified under different conditions. Electron paramagnetic resonance and radical quenching test suggested that surface-bound reactive oxides species and singlet oxygen were the main reactive oxides species in this reaction. Electrochemical analysis indicated that CN@Fe-10 had a good electrical conductivity and electron transferred did occur among CN@Fe-10 surface, peroxymonosulfate and sulfadiazine. X-ray photoelectron spectroscopy suggested that Fe0, Fe3C, pyridine nitrogen and graphite nitrogen were the potential active sites for peroxymonosulfate activation. Therefore, the work provided a practical approach for recycling biomass.

Copper Foam as Active Catalysts for the Borylation of α, ß-Unsaturated Compounds.

The use of simple, inexpensive, and efficient methods to construct carbon-boron and carbon-oxygen bonds has been a hot research topic in organic synthesis. We demonstrated that the desired ß-boronic acid products can be obtained under mild conditions using copper foam as an efficient heterogeneous catalyst. The structure of copper foam before and after the reaction was investigated by polarized light microscopy (PM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and the results have shown that the structure of the catalyst copper foam remained unchanged before and after the reaction. The XPS test results showed that the Cu(0) content increased after the reaction, indicating that copper may be involved in the boron addition reaction. The specific optimization conditions were as follows: CH3COCH3 and H2O were used as mixed solvents, 4-methoxychalcone was used as the raw material, 8 mg of catalyst was used and the reaction was carried out at room temperature and under air for 10 h. The yield of the product obtained was up to 92%, and the catalytic efficiency of the catalytic material remained largely unchanged after five cycles of use.

Synthesis and pharmacological characterization of glucopyranosyl-conjugated benzyl derivatives as novel selective cytotoxic agents against colon cancer.

Glucopyranosyl-conjugated benzyl derivatives containing a [1,2,3]-triazole linker were synthesized. Benzyl served as an important pharmacophore in anti-cancer compounds. Compound 8d inhibited the proliferation of colorectal cancer cells with the potency comparable to 5-fluorouracil (5-FU) with improved selectivity towards cancer cells. The antiproliferative activity of 8d is achieved through triggering apoptotic cell death.

Chitosan quaternary ammonium salt induced mitochondrial membrane permeability transition pore opening study in a spectroscopic perspective.

Chitosan is non-toxic, biodegradable and biocompatible. However, it is insoluble in water, which limits its applications in biomedical areas. Hydroxypropyltrimethyl ammonium chloride chitosan (HACC), a chitosan derivative, can be dissolved in physiological condition and has been widely used in the field of biomedicine and bioengineering. The biological effect of HACC has been extensively studied. However, it is rarely investigated at the subcellular level. To study the biological effect of HACC, mitochondria, energy-producing organelles in eukaryotes, were chosen as a model. The investigation mainly focused on the changes of mitochondrial membrane property in the presence of HACC. Results showed that HACC can induce the collapse of mitochondrial transmembrane potential (∆Ψm), the increase in mitochondrial membrane swelling and the decrease of mitochondrial membrane fluidity, demonstrating that mitochondrial membrane permeability transition pore (mPTP) opening happened. Possible mechanism of mPTP opening investigation indicated that it was occurred in a typical model. In addition, HACC can induce the release of cytochrome C (Cyt c) and affect the respiratory activity of mitochondria. The study will provide a lot of important information on biosafety evaluation of HACC.

Chitosan oligosaccharide combined with running benefited the immune status of rats.

Chitosan oligosaccharide (COS) degraded by chitosan, is an easily accessible and biocompatible natural molecule, which can facilitate the immune system. Running is one of the most effective forms of exercise. Persistence in running can effectively improve the body's resistance against pathogens. However, whether the combination of COS and running could benefit immune status still remains to be elucidated. We used Sprague-Dawley (SD) rats to explore the combinatory effect of COS and running. The organs and blood of the rats were collected after four weeks and the organ body mass index, biochemical and blood routine examination, cytokines, and T cells in the spleen and blood were detected and analyzed. In the group intragastric administration of COS only, the level of blood lactate dehydrogenase was increased, while the blood creatinine, red blood cells, lymphocytes, and serum TNF were decreased. Furthermore, COS combined with running promoted the development of spleen and lung, the level of lymphocytes, T cell and CD8+ T cell ratio in the blood, and serum TNF level. At the same time, the level of lactate dehydrogenase, serum IL-2, and T cell ratio in spleen were decreased. Therefore, our study indicated that COS combined with running could improve the immune status of rats.

Preparation of Bentonite/Chitosan Composite for Bleaching of Deteriorating Transformer Oil.

A novel adsorbent containing chitosan (CS) and bentonite (BT) was developed by mixing, drying, and calcining, and used as an adsorbent for the efficient bleaching of deteriorating transformer oil. The effects of calcination temperature, dosage of CS, adsorbent content, adsorption temperature, and adsorption time on the bleaching capacity of transformer oil were investigated. The structure of the adsorbent was also investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and N2 adsorption-desorption isotherm techniques. The results showed that there was only physical interaction between CS and BT; CS did transform to carbon (C) and covered the surface of BT. The specific surface area and micropore volume of the adsorbent were affected by the calcination process. The composite adsorbent offered an excellent bleaching performance. When the calcination temperature was 300 °C and dosage of CS was 5%, the composite adsorbent had the optimum bleaching properties. When the composite adsorbent content was 4%, the adsorption temperature was 50 °C and the adsorption time was 75 min, the colour number and transmittance of the deteriorating transformer oil decreased from no. 10 to no. 1 and increased from 70.1% to 99.5%, respectively.

Influence of Nano Titanium Dioxide and Clove Oil on Chitosan-Starch Film Characteristics.

The combined effects of nano titanium dioxide (TiO2-N) and clove oil (CO) on the physico-chemical, biological and structural properties of chitosan (CH)/starch (ST) films were investigated by using a solvent casting method. Results indicated that the incorporation of TiO2-N could improve the compactness of the film, increase the tensile strength (TS) and antioxidant activity, and decrease the water vapour permeability (WVP). As may be expected, the incorporation of CO into the film matrix decreased TS but increased the hydrophobicity as well as water vapour barrier antimicrobial and antioxidant properties. Fourier-transform infrared spectroscopy (FTIR) data supported intermolecular interactions between TiO2-N, CO and the film matrix. Use of a scanning electron microscope (SEM) showed that TiO2-N and CO were well dispersed and emulsified in the film network. Thermogravimetric (TG) and derivative thermogravimetric (DTG) curves demonstrated that TiO2-N and CO were well embedded in the film matrix, hence this blend film system could provide new formulation options for food packaging materials in the future.

Preparation of Modified Chitosan Microsphere-Supported Copper Catalysts for the Borylation of α,ß-Unsaturated Compounds.

Chitosan microspheres modified by 2-pyridinecarboxaldehyde were prepared and used in the construction of a heterogeneous catalyst loaded with nano-Cu prepared by a reduction reaction. The chemical structure of the catalyst was investigated by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). Under mild conditions, such as no ligand at room temperature, the catalyst was successfully applied to catalyze the borylation of α,ß-unsaturated receptors in a water-methanol medium, yielding 17%-100% of the corresponding -hydroxy product. Even after repeated use five times, the catalyst still exhibited excellent catalytic activity.

A fast responsive chromogenic and near-infrared fluorescence lighting-up probe for visual detection of toxic thiophenol in environmental water and living cells.

Thiophenols as high toxic environmental pollutants are poisonous for animals and aquatic organisms. Therefore, it is indispensable to monitor thiophenols in the environment. Herein, a novel near-infrared fluorescent probe was developed for the detection of thiophenols, which was easily prepared by one-step coupling of 2,4-dinitrobenzenesulfonyl chloride with Nile blue. The probe showed a significant near infrared (∼675 nm) fluorescence "turn-on" response to thiophenols with some good features including chromogenic reaction, high sensitivity and selectivity, fast response, near-infrared emission along with low detection limit (1.8 nM). The probe was employed to rapidly and visually determine thiophenols in several industrial wastewaters with good recoveries (90-110%). Moreover, this probe has been demonstrated good capability for imaging thiophenol in HeLa cells.

Chitosan-acorn starch-eugenol edible film: Physico-chemical, barrier, antimicrobial, antioxidant and structural properties.

Edible films from chitosan (CH) containing various amount of acorn starch (AS) and eugenol (Eu) were developed by casting and solvent-evaporation method, and their physico-chemical, barrier, antimicrobial, antioxidant and structural properties were also investigated. The experimental data showed that an appropriate proportion of AS could improve the mechanical and barrier properties of the film, and the incorporation of Eu in the film significantly improved the flexibility, barrier, hydrophobicity, antimicrobial and antioxidant properties. The results showed that the optimum comprehensive properties of the film were obtained when the mass ratio of AS to CH was 0.9 and the content of Eu was 9%. Possible intermolecular interactions between CH, AS and Eu were confirmed by Fourier-transform infrared spectroscopy (FTIR). SEM indicated that a good compatibility was present between CH and AS, and Eu was well emulsified and dispersed in the film matrix network. TG and DTG curves further confirmed Eu present in the film matrix network. Such edible films can provide new ways for packaging industries in developing active packaging materials.

Preparation and characterisation of carboxymethyl-chitosan/sodium phytate composite membranes for adsorption in transformer oil.

Adsorption of metal impurities from transformer oil was studied using a novel porous membrane. A solution of N, O­carboxymethyl­chitosan (CMC) and sodium phytate (SP) was blended to prepare a novel porous membrane for the metal impurities adsorption from transformer oil. The chemical structure of the membranes was characterised by their FTIR spectra, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and video camera observations. The effects of the SP content of the membrane, contact time, and contact temperature on adsorption of copper, iron, and aluminium impurities were studied. The FTIR spectra and thermogravimetric curves of the membranes indicated good compatibility between CMC and SP. The SEM and video camera observations suggested that CMC-SP composite membranes had a mature, porous structure. The experimental results showed that the SP content significantly affected the adsorption capacity of a CMC membrane. The maximum adsorption percentages of elemental copper, iron, and aluminium were 88.12%, 82.35%, and 80.36% when the SP ratio was 80% at 60 °C.

Lipid-lowering activities of chitosan and its quaternary ammonium salt for the hyperlipidemia rats induced by high-fat diets.

The lipid-lowering activities of chitosan (CS) and its quaternary ammonium salt (HACC) with two molecular weights (CS1, 2.5 × 105; HACC1, 2.4 × 105; CS2, 3.8 × 104; HACC2, 3.5 × 104) were evaluated for the rats fed with high-fat diets, respectively. The results showed that oral four CS samples resulted in the significant decrease of food efficiency ratio with the increase of fecal fat and cholesterol excretion (P < 0.05) compared with high-fat control group. Furthermore, the lipid-mediated oxidative stress and lipid levels in plasma and liver reduced, and hepatic lipase and lipoprotein lipase activities increased after the administration of CS and HACC. But the lipid-lowering effects of the four CS samples were different, which was HACC2 > HACC1 > CS2 > CS1 successively. The findings indicated that CS and HACC could reduce the absorption of dietary fat and cholesterol in vivo, which helped to alleviate hyperlipidemia and fatty liver effectively in the rats.

Glycine betaine intercalated layered double hydroxide modified quaternized chitosan/polyvinyl alcohol composite membranes for alkaline direct methanol fuel cells.

Utilization of chitosan as the host polymer of anion exchange membranes (AEMs) can avoid the carcinogenic chloromethylation step which is indispensable for aromatic polymers during their quaternization process. To further improve the ionic conductivity and mechanical stability, a hydroxide ion conductor (layered double hydroxides, LDHs) was intercalated by glycine betaine and then incorporated to quaternized chitosan and polyvinyl alcohol mixed matrix to prepare AEMs. Due to intercalated organic ions, the LDHs can be homogeneously dispersed in the matrix, thus promoting the load transfer from the matrix to stiff LDHs. The tensile strength and elongation of the composite membrane (5% intercalated LDHs content) are 23.6 MPa and 51.4% which are 71% and 44% respectively higher than those of the pure QCS/PVA membrane. Moreover, the hydroxide ion conductor (LDHs) and the intercalated quaternary ammonium groups could act as new OH- conductive sites and further enhance the ionic conductivity. The membrane with 5 wt.% intercalated LDHs loading shows ionic conductivity of ˜35.7 mS cm-1 (80 °C) and peak power density of 97.8 mW cm-2 which are respectively 42% and ˜50% higher than those of the pure membrane. Furthermore, better alkaline stability was also proved in the composite system, and the ionic conductivity of the composite membrane can retain 70% (only 49% for the pure membrane) even after immersing in a 1 M KOH for 168 h.

Microcalorimetric and microscopic studies of the effect of chitosan quaternary ammonium salt on mitochondria.

Chitosan quaternary ammonium salt (HACC) has been regarded as an effective biomedical carrier with good application because of its good water-solubility, high cationic potential and strong cell adhesion. Mitochondria are important organelle involved in ATP production and are the center of energy metabolism. In this work, we firstly investigated the effect of HACC on the thermogenic curve of isolated mitochondrial metabolism by microcalorimetry. The results showed that different concentration of HACC had great influence on the mitochondrial energy metabolism. Specifically, low level of HACC stimulated the metabolic activity of mitochondria and the inhibition was found with high concentration of HACC. Then, the effect of HACC on mitochondrial respiratory chain was studied, which was consistent with the results of microcalorimetry. Finally, the alteration of mitochondrial structure induced by HACC was observed and it showed that the membrane of mitochondria was dramatically damaged. These new findings can help us deeply understand the influence and action mechanism of HACC in the metabolic process and provide theoretical and practical foundation for the biosafety of HACC as a medical carrier.

Rapid and Visual Detection of Benzoyl Peroxide in Food by a Colorimetric and Ratiometric Fluorescent Probe.

A coumarin-based fluorescent probe was prepared for rapid and visual detection of benzoyl peroxide. The probe could quantitatively determine benzoyl peroxide with fast response (<6 min), high sensitivity, and low limit of detection (163 nM). The probe exhibited good response toward benzoyl peroxide with a significant color change from blue to yellow along with fluorescence color alteration from red to blue. The probe determined benzoyl peroxide in real food samples (wheat flour, noodle, and dumpling flour) with good recoveries (90-114%). Furthermore, the probe was prepared into a paper-based test kit to determine benzoyl peroxide (30-100 µM) in real food samples with noticeable color and fluorescence change.

Physical, antibacterial and antioxidant properties of chitosan films containing hardleaf oatchestnut starch and Litsea cubeba oil.

More and more attention was attached to food safety, it is necessary to endow food packaging films with good antibacterial and antioxidant properties Edible films based on chitosan (CH), hardleaf oatchestnut starch (HOS) and Litsea cubeba oil (LEO) were prepared by solution casting. The properties and structures of the blend film with different proportion (xCH/yHOS) were evaluated. The CH-HOS films were firstly prepared by blending CH solution with HOS paste. The tensile strength (TS) and DPPH radical scavenging ability of CH-HOS films increased from 27.33 MPa to 33.54 MPa and 20.67% to 52.34%, respectively, and water vapor permeability (WVP) decreased from 1.531 × 10-11 g m-1 pa-1 s-1 to 1.491 × 10-11 g m-1 pa-1 s-1, with the HOS content increased from the ratio of 1:0 to 1:1. Then, the LEO was added to 1CH-1HOS films. Tensile strength (TS), water vapor permeability, moisture absorption and total soluble matter (TSM) of the 1CH-1HOS film were remarkably decreased with 16%LEO. Meanwhile, the static contact angle and antimicrobial activity of 1CH-1HOS-16LEO film increased significantly. Hence, this blend film system has great potential for food packaging in the future.

Chitosan combined with swimming promotes health in rats.

PURPOSE: Chitosan is an easily accessible and biocompatible natural molecule which facilitate the immune system. In recent studies, chitosan is being applied to the drug nanosphere to deliver drugs. However, whether chitosan could promote health under exercising condition remains yet to be elucidated. Hence, we designed to investigate the effect of chitosan on swimming rats. METHODS: Sprague-Dawley (SD) rats were divided into four groups, exercise with chitosan, exercise with water, sedentary with chitosan, and sedentary with water. After four weeks of exercise and chitosan/water gavage, the blood was collected, and its biochemical index, complete blood count, and related parameters, and cytokines were detected and analyzed. RESULTS: The level of blood urea nitrogen (p = 0.0380), total cholesterol (p = 0.048), and low-density lipoprotein (p = 0.0338) were decreased, while the number of red blood cells (p = 0.001), hematocrit (p = 0.01), and mean corpuscular volume (p = 0.039) were increased in chitosan group. Furthermore, the combination of chitosan and swimming decreased the red blood cells distribution width. CONCLUSIONS: Our study support that chitosan could facilitate the health during exercise.

Superhydrophobic surfaces generated by one-pot spray-coating of chitosan-based nanoparticles.

Superhydrophobic surfaces have attracted great attention due to their attractive properties. Biopolymer-based low-cost and environmentally-friendly superhydrophobic coatings with easy-to-perform fabrication methods are always desirable. Herein, we report superhydrophobic surfaces using a one-step spray-coating of chitosan-based nanoparticles. The particles were easily prepared by a nanoprecipitation strategy using synthesized organosoluble chitosan stearoyl ester (CSSE). The resulting particles had an average size of 165 ∼ 235 nm depending on the applied concentration. Subsequently, spray-coating of such particles onto silicon wafer generated a surface with a water contact angle of 155 ±â€¯1°. SEM and AFM images exhibited a nano/microscaled roughness appeared on the coated surface. The superhydrophobic surfaces showed a stable superhydrophobic performance even after storage for 15 days, pH stability between pH 1 to pH 11 and thermal stability until a temperature no more than 50 °C. These properties would broaden the application fields of superhydrophobic surfaces as well as the chitosan itself.